Merge branch '10.5' into 'master'10.5

10.5

See merge request opensource-tracking/FreeFileSync!2

102 files changed, 2197 insertions, 1216 deletions

diff --git a/Changelog.txt b/Changelog.txt
index 90955af9..004aca9d 100755
--- a/Changelog.txt
+++ b/Changelog.txt
@@ -1,3 +1,22 @@
+FreeFileSync 10.5 [2018-10-11]
+------------------------------
+New file matching algorithm considering Unicode normalization
+User-configurable timeout for FTP and SFTP connections
+Obsoleted old CHM manual in favor of PDF
+Ignore case sensitivity during filter matching (Linux)
+Unicode-normalized and faster case-insensitive grid search
+New button to save current view filter settings as default
+Both slash and backslash can be used in filter expressions
+Improved Unicode case conversion routines
+Keyboard shortcuts for swap sides (F10) and view category (F11)
+Don't steal input focus when closing progress dialog (macOS)
+Fixed shutdown crash when accessing already destroyed state
+Fixed file grid column order not being preserved
+Fixed manual activation input fields being disabled (macOS)
+Fixed FTP parsing error due to invalid folder time
+Fixed statistics boxes background distortion (macOS)
+
+
 FreeFileSync 10.4 [2018-09-09]
 ------------------------------
 Allow overriding log folder path for gui and batch runs
diff --git a/FreeFileSync/Build/Languages/german.lng b/FreeFileSync/Build/Languages/german.lng
index 51d22174..4b79745a 100755
--- a/FreeFileSync/Build/Languages/german.lng
+++ b/FreeFileSync/Build/Languages/german.lng
@@ -7,11 +7,20 @@
 	<plural_definition>n == 1 ? 0 : 1</plural_definition>
 </header>
 
-<source>Default log path:</source>
-<target>Standardprotokollpfad:</target>
+<source>Access timeout (in seconds):</source>
+<target>Zeitlimit für Zugriff(in Sekunden):</target>
 
-<source>&Override default log path:</source>
-<target>&Standardprotokollpfad überschreiben:</target>
+<source>The server returned an error:</source>
+<target>Der Server hat einen Fehler zurückgegeben:</target>
+
+<source>You may close this page now and continue with FreeFileSync.</source>
+<target>Sie können diese Seite nun schließen und mit FreeFileSync fortfahren.</target>
+
+<source>Authentication failed.</source>
+<target>Authentifizierung fehlgeschlagen.</target>
+
+<source>Authentication completed.</source>
+<target>Authentifizierung abgeschlossen.</target>
 
 <source>Both sides have changed since last synchronization.</source>
 <target>Beide Seiten wurden seit der letzten Synchronisation verändert.</target>
@@ -193,9 +202,6 @@
 <source>File time tolerance</source>
 <target>Dateizeittoleranz</target>
 
-<source>Folder access timeout</source>
-<target>Zeitlimit für Ordnerzugriff</target>
-
 <source>Run with background priority</source>
 <target>Mit Hintergrundpriorität ausführen</target>
 
@@ -591,6 +597,12 @@ Tatsächlich: %y bytes
 <source>Unable to move %x to the recycle bin.</source>
 <target>%x kann nicht in den Papierkorb verschoben werden.</target>
 
+<source>Unable to access %x.</source>
+<target>Auf %x kann nicht zugegriffen werden.</target>
+
+<source>Cannot determine free disk space for %x.</source>
+<target>Der freie Speicherplatz für %x konnte nicht ermittelt werden.</target>
+
 <source>Cannot find %x.</source>
 <target>%x wurde nicht gefunden.</target>
 
@@ -603,18 +615,12 @@ Tatsächlich: %y bytes
 <source>Cannot delete symbolic link %x.</source>
 <target>Die symbolischen Verknüpfung %x kann nicht gelöscht werden.</target>
 
-<source>Cannot determine free disk space for %x.</source>
-<target>Der freie Speicherplatz für %x konnte nicht ermittelt werden.</target>
-
 <source>Incorrect command line:</source>
 <target>Ungültige Befehlszeile:</target>
 
 <source>The server does not support authentication via %x.</source>
 <target>Der Server unterstützt keine Authentifizierung über %x.</target>
 
-<source>Unable to access %x.</source>
-<target>Auf %x kann nicht zugegriffen werden.</target>
-
 <source>
 <pluralform>Operation timed out after 1 second.</pluralform>
 <pluralform>Operation timed out after %x seconds.</pluralform>
@@ -1144,6 +1150,9 @@ Die Befehlszeile wird ausgelöst, wenn:
 <source>Last x days:</source>
 <target>Letzte x Tage:</target>
 
+<source>&Override default log path:</source>
+<target>&Standardprotokollpfad überschreiben:</target>
+
 <source>Run a command after synchronization:</source>
 <target>Befehl nach Synchronisation ausführen:</target>
 
@@ -1309,6 +1318,9 @@ Dadurch wird ein konsistenter Datenstand auch bei schweren Fehlern garantiert.
 <source>Show all permanently hidden dialogs and warning messages again</source>
 <target>Alle dauerhaft versteckten Fenster und Warnmeldungen wieder anzeigen</target>
 
+<source>Default log path:</source>
+<target>Standardprotokollpfad:</target>
+
 <source>Remove old log files after x days:</source>
 <target>Alte Protokolldateien nach x Tagen entfernen:</target>
 
@@ -1954,12 +1966,6 @@ Dadurch wird ein konsistenter Datenstand auch bei schweren Fehlern garantiert.
 <source>Checking recycle bin failed for folder %x.</source>
 <target>Die Prüfung des Papierkorbs für Ordner %x ist fehlgeschlagen.</target>
 
-<source>The following XML elements could not be read:</source>
-<target>Die folgenden XML-Elemente konnten nicht gelesen werden:</target>
-
-<source>Configuration file %x is incomplete. The missing elements will be set to their default values.</source>
-<target>Die Konfigurationsdatei %x ist unvollständig. Die fehlenden Elemente werden auf ihre Standardwerte gesetzt.</target>
-
 <source>Prepare installation</source>
 <target>Installation vorbereiten</target>
 
diff --git a/FreeFileSync/Source/Makefile b/FreeFileSync/Source/Makefile
index efc73825..bd274138 100755
--- a/FreeFileSync/Source/Makefile
+++ b/FreeFileSync/Source/Makefile
@@ -68,14 +68,13 @@ CPP_FILES+=ui/gui_generated.cpp
 CPP_FILES+=ui/gui_status_handler.cpp
 CPP_FILES+=ui/main_dlg.cpp
 CPP_FILES+=ui/progress_indicator.cpp
-CPP_FILES+=ui/search.cpp
+CPP_FILES+=ui/search_grid.cpp
 CPP_FILES+=ui/small_dlgs.cpp
 CPP_FILES+=ui/sync_cfg.cpp
 CPP_FILES+=ui/taskbar.cpp
 CPP_FILES+=ui/tray_icon.cpp
 CPP_FILES+=ui/triple_splitter.cpp
 CPP_FILES+=ui/version_check.cpp
-CPP_FILES+=../../zen/xml_io.cpp
 CPP_FILES+=../../zen/recycler.cpp
 CPP_FILES+=../../zen/file_access.cpp
 CPP_FILES+=../../zen/file_io.cpp
@@ -118,11 +117,11 @@ install:
 
 	mkdir -p $(APPSHAREDIR)
 	cp -R ../Build/Languages/ \
-	../Build/Help/ \
 	../Build/ding.wav \
 	../Build/gong.wav \
 	../Build/harp.wav \
 	../Build/Resources.zip \
+	"../Build/User Manual.pdf" \
 	$(APPSHAREDIR)
 
 	mkdir -p $(DOCSHAREDIR)
diff --git a/FreeFileSync/Source/RealTimeSync/Makefile b/FreeFileSync/Source/RealTimeSync/Makefile
index 61aee2cb..900d2d22 100755
--- a/FreeFileSync/Source/RealTimeSync/Makefile
+++ b/FreeFileSync/Source/RealTimeSync/Makefile
@@ -23,7 +23,6 @@ CPP_FILES+=folder_selector2.cpp
 CPP_FILES+=../base/localization.cpp
 CPP_FILES+=../base/resolve_path.cpp
 CPP_FILES+=../base/ffs_paths.cpp
-CPP_FILES+=../../../zen/xml_io.cpp
 CPP_FILES+=../../../zen/dir_watcher.cpp
 CPP_FILES+=../../../zen/file_access.cpp
 CPP_FILES+=../../../zen/file_io.cpp
diff --git a/FreeFileSync/Source/RealTimeSync/application.cpp b/FreeFileSync/Source/RealTimeSync/application.cpp
index 69f7475f..6047468f 100755
--- a/FreeFileSync/Source/RealTimeSync/application.cpp
+++ b/FreeFileSync/Source/RealTimeSync/application.cpp
@@ -17,7 +17,7 @@
 #include "../base/localization.h"
 #include "../base/ffs_paths.h"
 #include "../base/return_codes.h"
-#include "../base/error_log.h"
+#include "../base/fatal_error.h"
 #include "../base/help_provider.h"
 #include "../base/resolve_path.h"
 
diff --git a/FreeFileSync/Source/RealTimeSync/folder_selector2.cpp b/FreeFileSync/Source/RealTimeSync/folder_selector2.cpp
index 0f895246..298d55b6 100755
--- a/FreeFileSync/Source/RealTimeSync/folder_selector2.cpp
+++ b/FreeFileSync/Source/RealTimeSync/folder_selector2.cpp
@@ -36,7 +36,7 @@ void setFolderPath(const Zstring& dirpath, wxTextCtrl* txtCtrl, wxWindow& toolti
         tooltipWnd.SetToolTip(utfTo<wxString>(folderPathFmt));
 
     if (staticText) //change static box label only if there is a real difference to what is shown in wxTextCtrl anyway
-        staticText->SetLabel(equalFilePath(appendSeparator(trimCpy(dirpath)), appendSeparator(folderPathFmt)) ? wxString(_("Drag && drop")) : utfTo<wxString>(folderPathFmt));
+        staticText->SetLabel(equalLocalPath(appendSeparator(trimCpy(dirpath)), appendSeparator(folderPathFmt)) ? wxString(_("Drag && drop")) : utfTo<wxString>(folderPathFmt));
 }
 }
 
@@ -150,9 +150,7 @@ void FolderSelector2::onSelectDir(wxCommandEvent& event)
 
 Zstring FolderSelector2::getPath() const
 {
-    Zstring path = utfTo<Zstring>(folderPathCtrl_.GetValue());
-
-    return path;
+    return utfTo<Zstring>(folderPathCtrl_.GetValue());
 }
 
 
diff --git a/FreeFileSync/Source/RealTimeSync/main_dlg.cpp b/FreeFileSync/Source/RealTimeSync/main_dlg.cpp
index 3ee8956b..e4dfcb56 100755
--- a/FreeFileSync/Source/RealTimeSync/main_dlg.cpp
+++ b/FreeFileSync/Source/RealTimeSync/main_dlg.cpp
@@ -18,7 +18,6 @@
 #include "tray_menu.h"
 #include "app_icon.h"
 #include "../base/help_provider.h"
-//#include "../base/process_xml.h"
 #include "../base/ffs_paths.h"
 #include "../version/version.h"
 
@@ -35,8 +34,8 @@ namespace
 
 std::wstring extractJobName(const Zstring& cfgFilePath)
 {
-    const Zstring shortName = afterLast(cfgFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL);
-    const Zstring jobName   = beforeLast(shortName, Zstr('.'), IF_MISSING_RETURN_ALL);
+    const Zstring fileName = afterLast(cfgFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL);
+    const Zstring jobName  = beforeLast(fileName, Zstr('.'), IF_MISSING_RETURN_ALL);
     return utfTo<std::wstring>(jobName);
 }
 
@@ -213,7 +212,7 @@ void MainDialog::OnStart(wxCommandEvent& event)
     Hide();
 
     XmlRealConfig currentCfg = getConfiguration();
-    const Zstring activeCfgFilePath = !equalFilePath(activeConfigFile_, lastRunConfigPath_) ? activeConfigFile_ : Zstring();
+    const Zstring activeCfgFilePath = !equalLocalPath(activeConfigFile_, lastRunConfigPath_) ? activeConfigFile_ : Zstring();
 
     switch (runFolderMonitor(currentCfg, ::extractJobName(activeCfgFilePath)))
     {
@@ -232,16 +231,16 @@ void MainDialog::OnStart(wxCommandEvent& event)
 
 void MainDialog::OnConfigSave(wxCommandEvent& event)
 {
-    Zstring defaultFilePath = !activeConfigFile_.empty() && !equalFilePath(activeConfigFile_, lastRunConfigPath_) ? activeConfigFile_ : Zstr("Realtime.ffs_real");
+    const Zstring defaultFilePath = !activeConfigFile_.empty() && !equalLocalPath(activeConfigFile_, lastRunConfigPath_) ? activeConfigFile_ : Zstr("Realtime.ffs_real");
+    auto defaultFolder   = utfTo<wxString>(beforeLast(defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE));
+    auto defaultFileName = utfTo<wxString>(afterLast (defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL));
+
     //attention: currentConfigFileName may be an imported *.ffs_batch file! We don't want to overwrite it with a GUI config!
-    if (endsWith(defaultFilePath, Zstr(".ffs_batch"), CmpFilePath()))
-        defaultFilePath = beforeLast(defaultFilePath, Zstr("."), IF_MISSING_RETURN_NONE) + Zstr(".ffs_real");
+    defaultFileName = beforeLast(defaultFileName, L'.', IF_MISSING_RETURN_ALL) + L".ffs_real";
 
     wxFileDialog filePicker(this,
                             wxString(),
-                            //OS X really needs dir/file separated like this:
-                            utfTo<wxString>(beforeLast(defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE)), //default dir
-                            utfTo<wxString>(afterLast (defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL)), //default file
+                            defaultFolder, defaultFileName, //OS X really needs dir/file separated like this
                             wxString(L"RealTimeSync (*.ffs_real)|*.ffs_real") + L"|" +_("All files") + L" (*.*)|*",
                             wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
     if (filePicker.ShowModal() != wxID_OK)
@@ -291,7 +290,7 @@ void MainDialog::setLastUsedConfig(const Zstring& filepath)
 {
     activeConfigFile_ = filepath;
 
-    const Zstring activeCfgFilePath = !equalFilePath(activeConfigFile_, lastRunConfigPath_) ? activeConfigFile_ : Zstring();
+    const Zstring activeCfgFilePath = !equalLocalPath(activeConfigFile_, lastRunConfigPath_) ? activeConfigFile_ : Zstring();
 
     if (!activeCfgFilePath.empty())
         SetTitle(utfTo<wxString>(activeCfgFilePath));
@@ -309,7 +308,7 @@ void MainDialog::OnConfigNew(wxCommandEvent& event)
 
 void MainDialog::OnConfigLoad(wxCommandEvent& event)
 {
-    const Zstring activeCfgFilePath = !equalFilePath(activeConfigFile_, lastRunConfigPath_) ? activeConfigFile_ : Zstring();
+    const Zstring activeCfgFilePath = !equalLocalPath(activeConfigFile_, lastRunConfigPath_) ? activeConfigFile_ : Zstring();
 
     wxFileDialog filePicker(this,
                             wxString(),
diff --git a/FreeFileSync/Source/RealTimeSync/monitor.cpp b/FreeFileSync/Source/RealTimeSync/monitor.cpp
index 84e3e363..8d12080b 100755
--- a/FreeFileSync/Source/RealTimeSync/monitor.cpp
+++ b/FreeFileSync/Source/RealTimeSync/monitor.cpp
@@ -22,14 +22,14 @@ const std::chrono::seconds FOLDER_EXISTENCE_CHECK_INTERVAL(1);
 
 
 //wait until all directories become available (again) + logs in network share
-std::set<Zstring, LessFilePath> waitForMissingDirs(const std::vector<Zstring>& folderPathPhrases, //throw FileError
-                                                   const std::function<void(const Zstring& folderPath)>& requestUiRefresh, std::chrono::milliseconds cbInterval)
+std::set<Zstring, LessLocalPath> waitForMissingDirs(const std::vector<Zstring>& folderPathPhrases, //throw FileError
+                                                    const std::function<void(const Zstring& folderPath)>& requestUiRefresh, std::chrono::milliseconds cbInterval)
 {
     //early failure! check for unsupported folder paths:
     for (const Zstring& protoName : { Zstr("FTP"), Zstr("SFTP"), Zstr("MTP") })
         for (const Zstring& phrase : folderPathPhrases)
             //hopefully clear enough now: https://freefilesync.org/forum/viewtopic.php?t=4302
-            if (startsWith(trimCpy(phrase), protoName + Zstr(":"), CmpAsciiNoCase()))
+            if (startsWithAsciiNoCase(trimCpy(phrase), protoName + Zstr(":")))
                 throw FileError(replaceCpy(_("The %x protocol does not support directory monitoring:"), L"%x", utfTo<std::wstring>(protoName)) + L"\n\n" + fmtPath(phrase));
 
     for (;;)
@@ -39,7 +39,7 @@ std::set<Zstring, LessFilePath> waitForMissingDirs(const std::vector<Zstring>& f
             Zstring folderPathPhrase;
             std::future<bool> folderAvailable;
         };
-        std::map<Zstring, FolderInfo, LessFilePath> folderInfos; //folderPath => FolderInfo
+        std::map<Zstring, FolderInfo, LessLocalPath> folderInfos; //folderPath => FolderInfo
 
         for (const Zstring& phrase : folderPathPhrases)
         {
@@ -50,12 +50,11 @@ std::set<Zstring, LessFilePath> waitForMissingDirs(const std::vector<Zstring>& f
                 folderInfos[folderPath] = { phrase, runAsync([folderPath]{ return dirAvailable(folderPath); }) };
         }
 
-        std::set<Zstring, LessFilePath> availablePaths;
-        std::set<Zstring, LessFilePath> missingPathPhrases;
-        for (auto& item : folderInfos)
+        std::set<Zstring, LessLocalPath> availablePaths;
+        std::set<Zstring, LessLocalPath> missingPathPhrases;
+        for (auto& [folderPath, folderInfo] : folderInfos)
         {
-            const Zstring& folderPath = item.first;
-            std::future<bool>& folderAvailable = item.second.folderAvailable;
+            std::future<bool>& folderAvailable = folderInfo.folderAvailable;
 
             while (folderAvailable.wait_for(cbInterval) != std::future_status::ready)
                 requestUiRefresh(folderPath); //throw X
@@ -63,7 +62,7 @@ std::set<Zstring, LessFilePath> waitForMissingDirs(const std::vector<Zstring>& f
             if (folderAvailable.get())
                 availablePaths.insert(folderPath);
             else
-                missingPathPhrases.insert(item.second.folderPathPhrase);
+                missingPathPhrases.insert(folderInfo.folderPathPhrase);
         }
         if (missingPathPhrases.empty())
             return availablePaths; //only return when all folders were found on *first* try!
@@ -119,7 +118,7 @@ struct WaitResult
 };
 
 
-WaitResult waitForChanges(const std::set<Zstring, LessFilePath>& folderPaths, //throw FileError
+WaitResult waitForChanges(const std::set<Zstring, LessLocalPath>& folderPaths, //throw FileError
                           const std::function<void(bool readyForSync)>& requestUiRefresh, std::chrono::milliseconds cbInterval)
 {
     assert(std::all_of(folderPaths.begin(), folderPaths.end(), [](const Zstring& folderPath) { return dirAvailable(folderPath); }));
@@ -154,19 +153,16 @@ WaitResult waitForChanges(const std::set<Zstring, LessFilePath>& folderPaths, //
             return false;
         }();
 
-        for (const auto& item : watches)
+        for (const auto& [folderPath, watcher] : watches)
         {
-            const Zstring& folderPath = item.first;
-            DirWatcher& watcher       = *item.second;
-
             //IMPORTANT CHECK: DirWatcher has problems detecting removal of top watched directories!
             if (checkDirNow)
                 if (!dirAvailable(folderPath)) //catch errors related to directory removal, e.g. ERROR_NETNAME_DELETED
                     return WaitResult(folderPath);
             try
             {
-                std::vector<DirWatcher::Entry> changedItems = watcher.getChanges([&] { requestUiRefresh(false /*readyForSync*/); /*throw X*/ },
-                                                                                 cbInterval); //throw FileError
+                std::vector<DirWatcher::Entry> changedItems = watcher->getChanges([&] { requestUiRefresh(false /*readyForSync*/); /*throw X*/ },
+                                                                                  cbInterval); //throw FileError
                 erase_if(changedItems, [](const DirWatcher::Entry& e)
                 {
                     return
@@ -226,7 +222,7 @@ void rts::monitorDirectories(const std::vector<Zstring>& folderPathPhrases, std:
     for (;;)
         try
         {
-            std::set<Zstring, LessFilePath> folderPaths = waitForMissingDirs(folderPathPhrases, [&](const Zstring& folderPath) { requestUiRefresh(&folderPath); }, cbInterval); //throw FileError
+            std::set<Zstring, LessLocalPath> folderPaths = waitForMissingDirs(folderPathPhrases, [&](const Zstring& folderPath) { requestUiRefresh(&folderPath); }, cbInterval); //throw FileError
 
             //schedule initial execution (*after* all directories have arrived)
             auto nextExecTime = std::chrono::steady_clock::now() + delay;
diff --git a/FreeFileSync/Source/RealTimeSync/tray_menu.cpp b/FreeFileSync/Source/RealTimeSync/tray_menu.cpp
index ddc5ea1c..667b480d 100755
--- a/FreeFileSync/Source/RealTimeSync/tray_menu.cpp
+++ b/FreeFileSync/Source/RealTimeSync/tray_menu.cpp
@@ -114,7 +114,7 @@ private:
         realtimeIcon.CopyFromBitmap(bmp);
         wxString tooltip = L"RealTimeSync\n" + statusTxt;
         if (!jobName_.empty())
-            tooltip += L"\n\"" + jobName_ + L"\"";
+            tooltip += L"\n\"" + jobName_ + L'"';
         SetIcon(realtimeIcon, tooltip);
     }
 
diff --git a/FreeFileSync/Source/RealTimeSync/xml_proc.cpp b/FreeFileSync/Source/RealTimeSync/xml_proc.cpp
index dd933e0d..1e8ca476 100755
--- a/FreeFileSync/Source/RealTimeSync/xml_proc.cpp
+++ b/FreeFileSync/Source/RealTimeSync/xml_proc.cpp
@@ -6,6 +6,7 @@
 
 #include "xml_proc.h"
 #include <zen/file_access.h>
+#include <zenxml/xml.h>
 #include <wx/intl.h>
 #include "../base/ffs_paths.h"
 #include "../base/localization.h"
@@ -75,7 +76,7 @@ void writeConfig(const XmlRealConfig& config, XmlOut& out)
 template <class ConfigType>
 void readConfig(const Zstring& filePath, RtsXmlType type, ConfigType& cfg, std::wstring& warningMsg) //throw FileError
 {
-    XmlDoc doc = loadXmlDocument(filePath); //throw FileError
+    XmlDoc doc = loadXml(filePath); //throw FileError
 
     if (getXmlTypeNoThrow(doc) != type) //noexcept
         throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
@@ -85,7 +86,7 @@ void readConfig(const Zstring& filePath, RtsXmlType type, ConfigType& cfg, std::
 
     try
     {
-        checkForMappingErrors(in, filePath); //throw FileError
+        checkXmlMappingErrors(in, filePath); //throw FileError
     }
     catch (const FileError& e) { warningMsg = e.toString(); }
 }
@@ -106,14 +107,14 @@ void rts::writeConfig(const XmlRealConfig& config, const Zstring& filepath) //th
     XmlOut out(doc);
     ::writeConfig(config, out);
 
-    saveXmlDocument(doc, filepath); //throw FileError
+    saveXml(doc, filepath); //throw FileError
 }
 
 
 void rts::readRealOrBatchConfig(const Zstring& filePath, XmlRealConfig& config, std::wstring& warningMsg) //throw FileError
 {
-    //do NOT use zen::loadStream as it will needlessly load even huge files!
-    XmlDoc doc = loadXmlDocument(filePath); //throw FileError; quick exit if file is not an FFS XML
+    XmlDoc doc = loadXml(filePath); //throw FileError
+    //quick exit if file is not an FFS XML
 
     const RtsXmlType xmlType = ::getXmlTypeNoThrow(doc);
 
@@ -123,7 +124,7 @@ void rts::readRealOrBatchConfig(const Zstring& filePath, XmlRealConfig& config,
         XmlIn in(doc);
 
         //read folder pairs
-        std::set<Zstring, LessFilePath> uniqueFolders;
+        std::set<Zstring, LessLocalPath> uniqueFolders;
 
         for (XmlIn inPair = in["FolderPairs"]["Pair"]; inPair; inPair.next())
         {
@@ -137,13 +138,13 @@ void rts::readRealOrBatchConfig(const Zstring& filePath, XmlRealConfig& config,
         }
 
         //don't consider failure a warning only:
-        checkForMappingErrors(in, filePath); //throw FileError
+        checkXmlMappingErrors(in, filePath); //throw FileError
 
         //---------------------------------------------------------------------------------------
 
         erase_if(uniqueFolders, [](const Zstring& str) { return trimCpy(str).empty(); });
         config.directories.assign(uniqueFolders.begin(), uniqueFolders.end());
-        config.commandline = Zstr("\"") + fff::getFreeFileSyncLauncherPath() + Zstr("\" \"") + filePath + Zstr("\"");
+        config.commandline = Zstr('"') + fff::getFreeFileSyncLauncherPath() + Zstr("\" \"") + filePath + Zstr('"');
     }
     else
         return readConfig(filePath, config, warningMsg); //throw FileError
@@ -157,7 +158,7 @@ wxLanguage rts::getProgramLanguage() //throw FileError
     XmlDoc doc;
     try
     {
-        doc = loadXmlDocument(filePath); //throw FileError
+        doc = loadXml(filePath); //throw FileError
     }
     catch (FileError&)
     {
@@ -174,6 +175,6 @@ wxLanguage rts::getProgramLanguage() //throw FileError
     wxLanguage lng = wxLANGUAGE_UNKNOWN;
     in["General"]["Language"].attribute("Name", lng);
 
-    checkForMappingErrors(in, filePath); //throw FileError
+    checkXmlMappingErrors(in, filePath); //throw FileError
     return lng;
 }
diff --git a/FreeFileSync/Source/RealTimeSync/xml_proc.h b/FreeFileSync/Source/RealTimeSync/xml_proc.h
index 305ca76d..ebad3c7e 100755
--- a/FreeFileSync/Source/RealTimeSync/xml_proc.h
+++ b/FreeFileSync/Source/RealTimeSync/xml_proc.h
@@ -8,7 +8,6 @@
 #define XML_PROC_H_0813748158321813490
 
 #include <vector>
-#include <zen/xml_io.h>
 #include <zen/zstring.h>
 #include <wx/language.h>
 
diff --git a/FreeFileSync/Source/base/algorithm.cpp b/FreeFileSync/Source/base/algorithm.cpp
index 044349b3..ff1bc787 100755
--- a/FreeFileSync/Source/base/algorithm.cpp
+++ b/FreeFileSync/Source/base/algorithm.cpp
@@ -192,13 +192,6 @@ bool fff::allElementsEqual(const FolderComparison& folderCmp)
 namespace
 {
 template <SelectedSide side> inline
-const InSyncDescrFile& getDescriptor(const InSyncFile& dbFile) { return dbFile.left; }
-
-template <> inline
-const InSyncDescrFile& getDescriptor<RIGHT_SIDE>(const InSyncFile& dbFile) { return dbFile.right; }
-
-
-template <SelectedSide side> inline
 bool matchesDbEntry(const FilePair& file, const InSyncFolder::FileList::value_type* dbFile, const std::vector<unsigned int>& ignoreTimeShiftMinutes)
 {
     if (file.isEmpty<side>())
@@ -206,10 +199,10 @@ bool matchesDbEntry(const FilePair& file, const InSyncFolder::FileList::value_ty
     else if (!dbFile)
         return false;
 
-    const Zstring&     shortNameDb = dbFile->first;
-    const InSyncDescrFile& descrDb = getDescriptor<side>(dbFile->second);
+    const Zstring&      fileNameDb = dbFile->first;
+    const InSyncDescrFile& descrDb = SelectParam<side>::ref(dbFile->second.left, dbFile->second.right);
 
-    return file.getItemName<side>() == shortNameDb && //detect changes in case (windows)
+    return getUnicodeNormalForm(file.getItemName<side>()) == getUnicodeNormalForm(fileNameDb) && //detect changes in case (but ignore Unicode normal forms)
            //respect 2 second FAT/FAT32 precision! copying a file to a FAT32 drive changes it's modification date by up to 2 seconds
            //we're not interested in "fileTimeTolerance" here!
            sameFileTime(file.getLastWriteTime<side>(), descrDb.modTime, 2, ignoreTimeShiftMinutes) &&
@@ -244,13 +237,6 @@ bool stillInSync(const InSyncFile& dbFile, CompareVariant compareVar, int fileTi
 
 //--------------------------------------------------------------------
 
-template <SelectedSide side> inline
-const InSyncDescrLink& getDescriptor(const InSyncSymlink& dbLink) { return dbLink.left; }
-
-template <> inline
-const InSyncDescrLink& getDescriptor<RIGHT_SIDE>(const InSyncSymlink& dbLink) { return dbLink.right; }
-
-
 //check whether database entry and current item match: *irrespective* of current comparison settings
 template <SelectedSide side> inline
 bool matchesDbEntry(const SymlinkPair& symlink, const InSyncFolder::SymlinkList::value_type* dbSymlink, const std::vector<unsigned int>& ignoreTimeShiftMinutes)
@@ -260,10 +246,10 @@ bool matchesDbEntry(const SymlinkPair& symlink, const InSyncFolder::SymlinkList:
     else if (!dbSymlink)
         return false;
 
-    const Zstring&     shortNameDb = dbSymlink->first;
-    const InSyncDescrLink& descrDb = getDescriptor<side>(dbSymlink->second);
+    const Zstring&      linkNameDb = dbSymlink->first;
+    const InSyncDescrLink& descrDb = SelectParam<side>::ref(dbSymlink->second.left, dbSymlink->second.right);
 
-    return symlink.getItemName<side>() == shortNameDb &&
+    return getUnicodeNormalForm(symlink.getItemName<side>()) == getUnicodeNormalForm(linkNameDb) &&
            //respect 2 second FAT/FAT32 precision! copying a file to a FAT32 drive changes its modification date by up to 2 seconds
            sameFileTime(symlink.getLastWriteTime<side>(), descrDb.modTime, 2, ignoreTimeShiftMinutes);
 }
@@ -297,14 +283,14 @@ bool stillInSync(const InSyncSymlink& dbLink, CompareVariant compareVar, int fil
 template <SelectedSide side> inline
 bool matchesDbEntry(const FolderPair& folder, const InSyncFolder::FolderList::value_type* dbFolder)
 {
-    if (folder.isEmpty<side>())
-        return !dbFolder || dbFolder->second.status == InSyncFolder::DIR_STATUS_STRAW_MAN;
-    else if (!dbFolder || dbFolder->second.status == InSyncFolder::DIR_STATUS_STRAW_MAN)
+    if (!dbFolder || dbFolder->second.status == InSyncFolder::DIR_STATUS_STRAW_MAN)
+        return folder.isEmpty<side>();
+    else if (folder.isEmpty<side>())
         return false;
 
-    const Zstring& shortNameDb = dbFolder->first;
+    const Zstring& folderNameDb = dbFolder->first;
 
-    return folder.getItemName<side>() == shortNameDb;
+    return getUnicodeNormalForm(folder.getItemName<side>()) == getUnicodeNormalForm(folderNameDb);
 }
 
 
@@ -344,7 +330,7 @@ private:
             {
                 if (dbFolder)
                 {
-                    auto it = dbFolder->files.find(file.getPairItemName());
+                    auto it = dbFolder->files.find(file.getItemNameAny());
                     if (it != dbFolder->files.end())
                         return &it->second;
                 }
@@ -382,7 +368,7 @@ private:
             const InSyncFolder* dbSubFolder = nullptr; //try to find corresponding database entry
             if (dbFolder)
             {
-                auto it = dbFolder->folders.find(folder.getPairItemName());
+                auto it = dbFolder->folders.find(folder.getItemNameAny());
                 if (it != dbFolder->folders.end())
                     dbSubFolder = &it->second;
             }
@@ -393,18 +379,18 @@ private:
 
     void detectMovePairs(const InSyncFolder& container) const
     {
-        for (auto& dbFile : container.files)
-            findAndSetMovePair(dbFile.second);
+        for (const auto& [fileName, dbAttrib] : container.files)
+            findAndSetMovePair(dbAttrib);
 
-        for (auto& dbFolder : container.folders)
-            detectMovePairs(dbFolder.second);
+        for (const auto& [folderName, subFolder] : container.folders)
+            detectMovePairs(subFolder);
     }
 
     template <SelectedSide side>
     static bool sameSizeAndDate(const FilePair& file, const InSyncFile& dbFile)
     {
         return file.getFileSize<side>() == dbFile.fileSize &&
-               sameFileTime(file.getLastWriteTime<side>(), getDescriptor<side>(dbFile).modTime, 2, {});
+               sameFileTime(file.getLastWriteTime<side>(), SelectParam<side>::ref(dbFile.left, dbFile.right).modTime, 2, {});
         //- respect 2 second FAT/FAT32 precision! not user-configurable!
         //- "ignoreTimeShiftMinutes" may lead to false positive move detections => let's be conservative and not allow it
         //  (time shift is only ever required during FAT DST switches)
@@ -427,7 +413,7 @@ private:
             //- note: exOneSideById isn't filled in this case, see recurse()
         }
 
-        const AFS::FileId fileId = getDescriptor<side>(dbFile).fileId;
+        const AFS::FileId fileId = SelectParam<side>::ref(dbFile.left, dbFile.right).fileId;
         if (!fileId.empty())
         {
             auto it = exOneSideById.find(fileId);
@@ -484,7 +470,7 @@ private:
 
        FAT caveat: File Ids are generally not stable when file is either moved or renamed!
        => 1. Move/rename operations on FAT cannot be detected reliably.
-       => 2. database generally contains wrong file ID on FAT after renaming from .ffs_tmp files => correct file Ids in database only after next sync
+       => 2. database generally contains wrong file ID on FAT after renaming from .ffs_tmp files => correct file IDs in database only after next sync
        => 3. even exFAT screws up (but less than FAT) and changes IDs after file move. Did they learn nothing from the past?
     */
 };
@@ -535,7 +521,7 @@ private:
         const InSyncFolder::FileList::value_type* dbEntry = nullptr;
         if (dbFolder)
         {
-            auto it = dbFolder->files.find(file.getPairItemName());
+            auto it = dbFolder->files.find(file.getItemNameAny());
             if (it != dbFolder->files.end())
                 dbEntry = &*it;
         }
@@ -571,7 +557,7 @@ private:
         const InSyncFolder::SymlinkList::value_type* dbEntry = nullptr;
         if (dbFolder)
         {
-            auto it = dbFolder->symlinks.find(symlink.getPairItemName());
+            auto it = dbFolder->symlinks.find(symlink.getItemNameAny());
             if (it != dbFolder->symlinks.end())
                 dbEntry = &*it;
         }
@@ -612,7 +598,7 @@ private:
         const InSyncFolder::FolderList::value_type* dbEntry = nullptr;
         if (dbFolder)
         {
-            auto it = dbFolder->folders.find(folder.getPairItemName());
+            auto it = dbFolder->folders.find(folder.getItemNameAny());
             if (it != dbFolder->folders.end())
                 dbEntry = &*it;
         }
@@ -890,19 +876,19 @@ private:
     void processFile(FilePair& file) const
     {
         if (Eval<strategy>::process(file))
-            file.setActive(filterProc.passFileFilter(file.getPairRelativePath()));
+            file.setActive(filterProc.passFileFilter(file.getRelativePathAny()));
     }
 
     void processLink(SymlinkPair& symlink) const
     {
         if (Eval<strategy>::process(symlink))
-            symlink.setActive(filterProc.passFileFilter(symlink.getPairRelativePath()));
+            symlink.setActive(filterProc.passFileFilter(symlink.getRelativePathAny()));
     }
 
     void processDir(FolderPair& folder) const
     {
         bool childItemMightMatch = true;
-        const bool filterPassed = filterProc.passDirFilter(folder.getPairRelativePath(), &childItemMightMatch);
+        const bool filterPassed = filterProc.passDirFilter(folder.getRelativePathAny(), &childItemMightMatch);
 
         if (Eval<strategy>::process(folder))
             folder.setActive(filterPassed);
@@ -1138,7 +1124,7 @@ std::optional<PathDependency> fff::getPathDependency(const AbstractPath& basePat
             const auto& relPathP = leftParent ? relPathL : relPathR;
             const auto& relPathC = leftParent ? relPathR : relPathL;
 
-            if (std::equal(relPathP.begin(), relPathP.end(), relPathC.begin(), [](const Zstring& lhs, const Zstring& rhs) { return equalFilePath(lhs, rhs); }))
+            if (std::equal(relPathP.begin(), relPathP.end(), relPathC.begin(), [](const Zstring& lhs, const Zstring& rhs) { return equalNoCase(lhs, rhs); }))
             {
                 Zstring relDirPath;
                 std::for_each(relPathC.begin() + relPathP.size(), relPathC.end(), [&](const Zstring& itemName)
@@ -1591,9 +1577,9 @@ void fff::deleteFromGridAndHD(const std::vector<FileSystemObject*>& rowsToDelete
     {
         std::wstring msg = _("The recycle bin is not supported by the following folders. Deleted or overwritten files will not be able to be restored:") + L"\n";
 
-        for (const auto& item : recyclerSupported)
-            if (!item.second)
-                msg += L"\n" + AFS::getDisplayPath(item.first);
+        for (const auto& [folderPath, supported] : recyclerSupported)
+            if (!supported)
+                msg += L"\n" + AFS::getDisplayPath(folderPath);
 
         callback.reportWarning(msg, warnRecyclerMissing); //throw?
     }
diff --git a/FreeFileSync/Source/base/algorithm.h b/FreeFileSync/Source/base/algorithm.h
index 7e073945..a8facb9d 100755
--- a/FreeFileSync/Source/base/algorithm.h
+++ b/FreeFileSync/Source/base/algorithm.h
@@ -81,7 +81,7 @@ struct FileDescriptor
 };
 bool operator<(const FileDescriptor& lhs, const FileDescriptor& rhs);
 
-//get native Win32 paths or create temporary copy for SFTP/MTP, ect.
+//get native Win32 paths or create temporary copy for SFTP/MTP, etc.
 class TempFileBuffer
 {
 public:
diff --git a/FreeFileSync/Source/base/application.cpp b/FreeFileSync/Source/base/application.cpp
index a160ff06..4707fd98 100755
--- a/FreeFileSync/Source/base/application.cpp
+++ b/FreeFileSync/Source/base/application.cpp
@@ -18,16 +18,14 @@
 #include "synchronization.h"
 #include "help_provider.h"
 #include "process_xml.h"
-#include "error_log.h"
+#include "fatal_error.h"
 #include "resolve_path.h"
 #include "generate_logfile.h"
 #include "../ui/batch_status_handler.h"
 #include "../ui/main_dlg.h"
-//#include "../fs/concrete.h"
 
     #include <gtk/gtk.h>
 
-
 using namespace zen;
 using namespace fff;
 
@@ -181,27 +179,27 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
             if (it == arg.begin()) return false; //require at least one prefix character
 
             const Zstring argTmp(it, arg.end());
-            return strEqual(argTmp, Zstr("help"), CmpAsciiNoCase()) ||
-                   strEqual(argTmp, Zstr("h"),    CmpAsciiNoCase()) ||
+            return equalAsciiNoCase(argTmp, Zstr("help")) ||
+                   equalAsciiNoCase(argTmp, Zstr("h"))    ||
                    argTmp == Zstr("?");
         };
 
         auto isCommandLineOption = [&](const Zstring& arg)
         {
-            return strEqual(arg, optionEdit,     CmpAsciiNoCase()) ||
-                   strEqual(arg, optionLeftDir,  CmpAsciiNoCase()) ||
-                   strEqual(arg, optionRightDir, CmpAsciiNoCase()) ||
-                   strEqual(arg, optionDirPair,  CmpAsciiNoCase()) ||
-                   strEqual(arg, optionSendTo,   CmpAsciiNoCase()) ||
+            return equalAsciiNoCase(arg, optionEdit    ) ||
+                   equalAsciiNoCase(arg, optionLeftDir ) ||
+                   equalAsciiNoCase(arg, optionRightDir) ||
+                   equalAsciiNoCase(arg, optionDirPair ) ||
+                   equalAsciiNoCase(arg, optionSendTo  ) ||
                    syntaxHelpRequested(arg);
         };
 
         for (auto it = commandArgs.begin(); it != commandArgs.end(); ++it)
             if (syntaxHelpRequested(*it))
                 return showSyntaxHelp();
-            else if (strEqual(*it, optionEdit, CmpAsciiNoCase()))
+            else if (equalAsciiNoCase(*it, optionEdit))
                 openForEdit = true;
-            else if (strEqual(*it, optionLeftDir, CmpAsciiNoCase()))
+            else if (equalAsciiNoCase(*it, optionLeftDir))
             {
                 if (++it == commandArgs.end() || isCommandLineOption(*it))
                 {
@@ -210,7 +208,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
                 }
                 dirPathPhrasesLeft.push_back(*it);
             }
-            else if (strEqual(*it, optionRightDir, CmpAsciiNoCase()))
+            else if (equalAsciiNoCase(*it, optionRightDir))
             {
                 if (++it == commandArgs.end() || isCommandLineOption(*it))
                 {
@@ -219,7 +217,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
                 }
                 dirPathPhrasesRight.push_back(*it);
             }
-            else if (strEqual(*it, optionDirPair, CmpAsciiNoCase()))
+            else if (equalAsciiNoCase(*it, optionDirPair))
             {
                 if (++it == commandArgs.end() || isCommandLineOption(*it))
                 {
@@ -235,7 +233,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
                 }
                 dirPathPhrasePairs.back().second = *it;
             }
-            else if (strEqual(*it, optionSendTo, CmpAsciiNoCase()))
+            else if (equalAsciiNoCase(*it, optionSendTo))
             {
                 for (size_t i = 0; ; ++i)
                 {
@@ -245,7 +243,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
                         break;
                     }
 
-                    if (i < 2) //-SendTo with more than 2 paths? Doesn't make any sense, does it!?
+                    if (i < 2) //else: -SendTo with more than 2 paths? Doesn't make any sense, does it!?
                     {
                         //for -SendTo we expect a list of full native paths, not "phrases" that need to be resolved!
                         auto getFolderPath = [](Zstring itemPath)
@@ -266,7 +264,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
                         else
                         {
                             const Zstring folderPath = getFolderPath(*it);
-                            if (!equalFilePath(dirPathPhrasePairs.back().first, folderPath)) //user accidentally sending to two files, which each time yield the same parent folder
+                            if (dirPathPhrasePairs.back().first != folderPath) //else: user accidentally sending to two files, which each time yield the same parent folder
                                 dirPathPhrasePairs.back().second = folderPath;
                         }
                     }
@@ -439,15 +437,15 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
             return;
         }
 
-        std::vector<Zstring> filepaths;
-        for (const auto& item : configFiles)
-            filepaths.push_back(item.first);
+        std::vector<Zstring> filePaths;
+        for (const auto& [filePath, xmlType] : configFiles)
+            filePaths.push_back(filePath);
 
         XmlGuiConfig guiCfg; //structure to receive gui settings with default values
         try
         {
             std::wstring warningMsg;
-            readAnyConfig(filepaths, guiCfg, warningMsg); //throw FileError
+            readAnyConfig(filePaths, guiCfg, warningMsg); //throw FileError
 
             if (!warningMsg.empty())
                 showNotificationDialog(nullptr, DialogInfoType::WARNING, PopupDialogCfg().setDetailInstructions(warningMsg));
@@ -458,7 +456,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
             notifyFatalError(e.toString(), _("Error"));
             return;
         }
-        runGuiMode(globalConfigFilePath, guiCfg, filepaths, !openForEdit /*startComparison*/);
+        runGuiMode(globalConfigFilePath, guiCfg, filePaths, !openForEdit /*startComparison*/);
     }
 }
 
@@ -580,7 +578,6 @@ void runBatchMode(const Zstring& globalConfigFilePath, const XmlBatchConfig& bat
                                              globalCfg.fileTimeTolerance,
                                              showPopupAllowed, //allowUserInteraction
                                              globalCfg.runWithBackgroundPriority,
-                                             globalCfg.folderAccessTimeout,
                                              globalCfg.createLockFile,
                                              dirLocks,
                                              extractCompareCfg(batchCfg.mainCfg),
@@ -593,7 +590,6 @@ void runBatchMode(const Zstring& globalConfigFilePath, const XmlBatchConfig& bat
                     globalCfg.copyFilePermissions,
                     globalCfg.failSafeFileCopy,
                     globalCfg.runWithBackgroundPriority,
-                    globalCfg.folderAccessTimeout,
                     extractSyncCfg(batchCfg.mainCfg),
                     cmpResult,
                     deviceParallelOps,
@@ -609,7 +605,7 @@ void runBatchMode(const Zstring& globalConfigFilePath, const XmlBatchConfig& bat
 
     //update last sync stats for the selected cfg file
     for (ConfigFileItem& cfi : globalCfg.gui.mainDlg.cfgFileHistory)
-        if (equalFilePath(cfi.cfgFilePath, cfgFilePath))
+        if (equalLocalPath(cfi.cfgFilePath, cfgFilePath))
         {
             if (r.finalStatus != SyncResult::ABORTED)
                 cfi.lastSyncTime = std::chrono::system_clock::to_time_t(syncStartTime);
diff --git a/FreeFileSync/Source/base/comparison.cpp b/FreeFileSync/Source/base/comparison.cpp
index 84b392cf..ce601ac8 100755
--- a/FreeFileSync/Source/base/comparison.cpp
+++ b/FreeFileSync/Source/base/comparison.cpp
@@ -69,7 +69,6 @@ struct ResolvedBaseFolders
 
 
 ResolvedBaseFolders initializeBaseFolders(const std::vector<FolderPairCfg>& fpCfgList, const std::map<AbstractPath, size_t>& deviceParallelOps,
-                                          std::chrono::seconds folderAccessTimeout,
                                           bool allowUserInteraction,
                                           bool& warnFolderNotExisting,
                                           ProcessCallback& callback /*throw X*/)
@@ -95,19 +94,19 @@ ResolvedBaseFolders initializeBaseFolders(const std::vector<FolderPairCfg>& fpCf
         }
 
         const FolderStatus status = getFolderStatusNonBlocking(uniqueBaseFolders, deviceParallelOps, //re-check *all* directories on each try!
-                                                               folderAccessTimeout, allowUserInteraction, callback); //throw X
+                                                               allowUserInteraction, callback); //throw X
         output.existingBaseFolders = status.existing;
         notExisting                = status.notExisting;
         if (!status.failedChecks.empty())
         {
             std::wstring msg = _("Cannot find the following folders:") + L"\n";
 
-            for (const auto& fc : status.failedChecks)
-                msg += L"\n" + AFS::getDisplayPath(fc.first);
+            for (const auto& [folderPath, error] : status.failedChecks)
+                msg += L"\n" + AFS::getDisplayPath(folderPath);
 
             msg += L"\n___________________________________________";
-            for (const auto& fc : status.failedChecks)
-                msg += L"\n\n" + replaceCpy(fc.second.toString(), L"\n\n", L"\n");
+            for (const auto& [folderPath, error] : status.failedChecks)
+                msg += L"\n\n" + replaceCpy(error.toString(), L"\n\n", L"\n");
 
             throw FileError(msg);
         }
@@ -262,7 +261,8 @@ void categorizeSymlinkByTime(SymlinkPair& symlink)
             //1. SYMLINK_EQUAL may only be set if short names match in case: InSyncFolder's mapping tables use short name as a key! see db_file.cpp
             //2. harmonize with "bool stillInSync()" in algorithm.cpp
 
-            if (symlink.getItemName<LEFT_SIDE>() == symlink.getItemName<RIGHT_SIDE>())
+            if (getUnicodeNormalForm(symlink.getItemName<LEFT_SIDE >()) ==
+                getUnicodeNormalForm(symlink.getItemName<RIGHT_SIDE>()))
                 symlink.setCategory<FILE_EQUAL>();
             else
                 symlink.setCategoryDiffMetadata(getDescrDiffMetaShortnameCase(symlink));
@@ -311,7 +311,8 @@ std::shared_ptr<BaseFolderPair> ComparisonBuffer::compareByTimeSize(const Resolv
                 //3. harmonize with "bool stillInSync()" in algorithm.cpp, FilePair::setSyncedTo() in file_hierarchy.h
                 if (file->getFileSize<LEFT_SIDE>() == file->getFileSize<RIGHT_SIDE>())
                 {
-                    if (file->getItemName<LEFT_SIDE>() == file->getItemName<RIGHT_SIDE>())
+                    if (getUnicodeNormalForm(file->getItemName<LEFT_SIDE >()) ==
+                        getUnicodeNormalForm(file->getItemName<RIGHT_SIDE>()))
                         file->setCategory<FILE_EQUAL>();
                     else
                         file->setCategoryDiffMetadata(getDescrDiffMetaShortnameCase(*file));
@@ -368,7 +369,8 @@ void categorizeSymlinkByContent(SymlinkPair& symlink, ProcessCallback& callback)
             //2. harmonize with "bool stillInSync()" in algorithm.cpp, FilePair::setSyncedTo() in file_hierarchy.h
 
             //symlinks have same "content"
-            if (symlink.getItemName<LEFT_SIDE>() != symlink.getItemName<RIGHT_SIDE>())
+            if (getUnicodeNormalForm(symlink.getItemName<LEFT_SIDE >()) !=
+                getUnicodeNormalForm(symlink.getItemName<RIGHT_SIDE>()))
                 symlink.setCategoryDiffMetadata(getDescrDiffMetaShortnameCase(symlink));
             //else if (!sameFileTime(symlink.getLastWriteTime<LEFT_SIDE>(),
             //                       symlink.getLastWriteTime<RIGHT_SIDE>(), symlink.base().getFileTimeTolerance(), symlink.base().getIgnoredTimeShift()))
@@ -404,7 +406,8 @@ std::shared_ptr<BaseFolderPair> ComparisonBuffer::compareBySize(const ResolvedFo
         //3. harmonize with "bool stillInSync()" in algorithm.cpp, FilePair::setSyncedTo() in file_hierarchy.h
         if (file->getFileSize<LEFT_SIDE>() == file->getFileSize<RIGHT_SIDE>())
         {
-            if (file->getItemName<LEFT_SIDE>() == file->getItemName<RIGHT_SIDE>())
+            if (getUnicodeNormalForm(file->getItemName< LEFT_SIDE>()) ==
+                getUnicodeNormalForm(file->getItemName<RIGHT_SIDE>()))
                 file->setCategory<FILE_EQUAL>();
             else
                 file->setCategoryDiffMetadata(getDescrDiffMetaShortnameCase(*file));
@@ -433,7 +436,7 @@ namespace
 {
 void categorizeFileByContent(FilePair& file, const std::wstring& txtComparingContentOfFiles, AsyncCallback& acb, std::mutex& singleThread) //throw ThreadInterruption
 {
-    acb.reportStatus(replaceCpy(txtComparingContentOfFiles, L"%x", fmtPath(file.getPairRelativePath()))); //throw ThreadInterruption
+    acb.reportStatus(replaceCpy(txtComparingContentOfFiles, L"%x", fmtPath(file.getRelativePathAny()))); //throw ThreadInterruption
 
     bool haveSameContent = false;
     const std::wstring errMsg = tryReportingError([&]
@@ -462,7 +465,8 @@ void categorizeFileByContent(FilePair& file, const std::wstring& txtComparingCon
             //1. FILE_EQUAL may only be set if short names match in case: InSyncFolder's mapping tables use short name as a key! see db_file.cpp
             //2. FILE_EQUAL is expected to mean identical file sizes! See InSyncFile
             //3. harmonize with "bool stillInSync()" in algorithm.cpp, FilePair::setSyncedTo() in file_hierarchy.h
-            if (file.getItemName<LEFT_SIDE>() != file.getItemName<RIGHT_SIDE>())
+            if (getUnicodeNormalForm(file.getItemName< LEFT_SIDE>()) !=
+                getUnicodeNormalForm(file.getItemName<RIGHT_SIDE>()))
                 file.setCategoryDiffMetadata(getDescrDiffMetaShortnameCase(file));
 #if 0 //don't synchronize modtime only see FolderPairSyncer::synchronizeFileInt(), SO_COPY_METADATA_TO_*
             else if (!sameFileTime(file.getLastWriteTime<LEFT_SIDE>(),
@@ -520,12 +524,12 @@ std::list<std::shared_ptr<BaseFolderPair>> ComparisonBuffer::compareByContent(co
 
     const Zstringw txtConflictSkippedBinaryComparison = getConflictSkippedBinaryComparison(); //avoid premature pess.: save memory via ref-counted string
 
-    for (const auto& w : workLoad)
+    for (const auto& [folderPair, fpCfg] : workLoad)
     {
         std::vector<FilePair*> undefinedFiles;
         std::vector<SymlinkPair*> uncategorizedLinks;
         //run basis scan and retrieve candidates for binary comparison (files existing on both sides)
-        output.push_back(performComparison(w.first, w.second, undefinedFiles, uncategorizedLinks));
+        output.push_back(performComparison(folderPair, fpCfg, undefinedFiles, uncategorizedLinks));
 
         RingBuffer<FilePair*> filesToCompareBytewise;
         //content comparison of file content happens AFTER finding corresponding files and AFTER filtering
@@ -638,19 +642,19 @@ std::list<std::shared_ptr<BaseFolderPair>> ComparisonBuffer::compareByContent(co
 class MergeSides
 {
 public:
-    MergeSides(const std::map<Zstring, Zstringw, LessFilePath>& failedItemReads,
+    MergeSides(const std::map<ZstringNoCase, Zstringw>& errorsByRelPath,
                std::vector<FilePair*>& undefinedFilesOut,
                std::vector<SymlinkPair*>& undefinedSymlinksOut) :
-        failedItemReads_(failedItemReads),
+        errorsByRelPath_(errorsByRelPath),
         undefinedFiles_(undefinedFilesOut),
         undefinedSymlinks_(undefinedSymlinksOut) {}
 
     void execute(const FolderContainer& lhs, const FolderContainer& rhs, ContainerObject& output)
     {
-        auto it = failedItemReads_.find(Zstring()); //empty path if read-error for whole base directory
+        auto it = errorsByRelPath_.find(Zstring()); //empty path if read-error for whole base directory
 
         mergeTwoSides(lhs, rhs,
-                      it != failedItemReads_.end() ? &it->second : nullptr,
+                      it != errorsByRelPath_.end() ? &it->second : nullptr,
                       output);
     }
 
@@ -662,8 +666,8 @@ private:
 
     const Zstringw* checkFailedRead(FileSystemObject& fsObj, const Zstringw* errorMsg);
 
-    const std::map<Zstring, Zstringw, LessFilePath>& failedItemReads_; //base-relative paths or empty if read-error for whole base directory
-    std::vector<FilePair*>&   undefinedFiles_;
+    const std::map<ZstringNoCase, Zstringw>& errorsByRelPath_; //base-relative paths or empty if read-error for whole base directory
+    std::vector<FilePair*>&    undefinedFiles_;
     std::vector<SymlinkPair*>& undefinedSymlinks_;
 };
 
@@ -673,8 +677,8 @@ const Zstringw* MergeSides::checkFailedRead(FileSystemObject& fsObj, const Zstri
 {
     if (!errorMsg)
     {
-        auto it = failedItemReads_.find(fsObj.getPairRelativePath());
-        if (it != failedItemReads_.end())
+        auto it = errorsByRelPath_.find(fsObj.getRelativePathAny());
+        if (it != errorsByRelPath_.end())
             errorMsg = &it->second;
     }
 
@@ -691,65 +695,106 @@ const Zstringw* MergeSides::checkFailedRead(FileSystemObject& fsObj, const Zstri
 template <SelectedSide side>
 void MergeSides::fillOneSide(const FolderContainer& folderCont, const Zstringw* errorMsg, ContainerObject& output)
 {
-    for (const auto& file : folderCont.files)
+    for (const auto& [fileName, attrib] : folderCont.files)
     {
-        FilePair& newItem = output.addSubFile<side>(file.first, file.second);
+        FilePair& newItem = output.addSubFile<side>(fileName, attrib);
         checkFailedRead(newItem, errorMsg);
     }
 
-    for (const auto& symlink : folderCont.symlinks)
+    for (const auto& [linkName, attrib] : folderCont.symlinks)
     {
-        SymlinkPair& newItem = output.addSubLink<side>(symlink.first, symlink.second);
+        SymlinkPair& newItem = output.addSubLink<side>(linkName, attrib);
         checkFailedRead(newItem, errorMsg);
     }
 
-    for (const auto& dir : folderCont.folders)
+    for (const auto& [folderName, attrAndSub] : folderCont.folders)
     {
-        FolderPair& newFolder = output.addSubFolder<side>(dir.first, dir.second.first);
+        FolderPair& newFolder = output.addSubFolder<side>(folderName, attrAndSub.first);
         const Zstringw* errorMsgNew = checkFailedRead(newFolder, errorMsg);
-        fillOneSide<side>(dir.second.second, errorMsgNew, newFolder); //recurse
+        fillOneSide<side>(attrAndSub.second, errorMsgNew, newFolder); //recurse
     }
 }
 
 
-//perf: 70% faster than traversing over left and right containers + more natural default sequence
-//- 2 x lessKey vs 1 x cmpFilePath() => no significant difference
-//- simplify loop by placing the eob check at the beginning => slightly slower
 template <class MapType, class ProcessLeftOnly, class ProcessRightOnly, class ProcessBoth> inline
-void linearMerge(const MapType& mapLeft, const MapType& mapRight, ProcessLeftOnly lo, ProcessRightOnly ro, ProcessBoth bo)
+void matchFolders(const MapType& mapLeft, const MapType& mapRight, ProcessLeftOnly lo, ProcessRightOnly ro, ProcessBoth bo)
 {
-    auto itL = mapLeft .begin();
-    auto itR = mapRight.begin();
+    struct FileRef
+    {
+        Zstring normalName; //buffer expensive makeUpperCopy() calls!!
+        const typename MapType::value_type* ref;
+        bool leftSide;
+    };
+    std::vector<FileRef> fileList;
+    fileList.reserve(mapLeft.size() + mapRight.size()); //perf: ~5% shorter runtime
 
-    auto finishLeft  = [&] { std::for_each(itL, mapLeft .end(), lo); };
-    auto finishRight = [&] { std::for_each(itR, mapRight.end(), ro); };
+    for (const auto& item : mapLeft ) fileList.push_back({ makeUpperCopy(item.first), &item, true });
+    for (const auto& item : mapRight) fileList.push_back({ makeUpperCopy(item.first), &item, false });
 
-    if (itL == mapLeft .end()) return finishRight();
-    if (itR == mapRight.end()) return finishLeft ();
+    std::sort(fileList.begin(), fileList.end(), [&](const FileRef& lhs, const FileRef& rhs)
+    {
+        int rv = compareString(lhs.normalName, rhs.normalName);
+        if (rv != 0)
+            return rv < 0; //primary sort key: ignore unicode normal form and case
 
-    const auto lessKey = typename MapType::key_compare();
+        //perf: sorting by secondary/tertiary key here costs about 7% additional runtime
+        rv = compareString(getUnicodeNormalForm(lhs.ref->first), getUnicodeNormalForm(rhs.ref->first));
+        if (rv != 0)
+            return rv < 0; //secondary sort key: ignore unicode normal
 
-    for (;;)
-        if (lessKey(itL->first, itR->first))
-        {
-            lo(*itL);
-            if (++itL == mapLeft.end())
-                return finishRight();
-        }
-        else if (lessKey(itR->first, itL->first))
-        {
-            ro(*itR);
-            if (++itR == mapRight.end())
-                return finishLeft();
-        }
-        else
+        return lhs.ref->first < rhs.ref->first; //tertiary sort key: raw string value
+    });
+    //bonus: natural default sequence on file guid UI
+
+    auto tryMatchRange = [&](auto it, auto itLast)
+    {
+        const size_t equalCountL = std::count_if(it, itLast, [](const FileRef& fr) { return fr.leftSide; });
+        const size_t equalCountR = itLast - it - equalCountL;
+
+        if (equalCountL == 1 && equalCountR == 1) //we have a match
         {
-            bo(*itL, *itR);
-            ++itL; //
-            ++itR; //increment BOTH before checking for end of range!
-            if (itL == mapLeft .end()) return finishRight();
-            if (itR == mapRight.end()) return finishLeft ();
+            if (it->leftSide)
+                bo(*it[0].ref, *it[1].ref);
+            else
+                bo(*it[1].ref, *it[0].ref);
         }
+        else if (equalCountL == 0) //no match
+            std::for_each(it, itLast, [&](const FileRef& fr) { ro(*fr.ref); });
+        else if (equalCountR == 0) //no match
+            std::for_each(it, itLast, [&](const FileRef& fr) { lo(*fr.ref); });
+        else //ambiguous
+            return false;
+        return true;
+    };
+
+    for (auto it = fileList.begin(); it != fileList.end();)
+    {
+        //find equal range: ignore case, ignore Unicode normalization
+        auto itEndEq = std::find_if(it + 1, fileList.end(), [&](const FileRef& fr) { return fr.normalName != it->normalName; });
+        if (!tryMatchRange(it, itEndEq))
+            for (auto itCase = it; itCase != itEndEq;)
+            {
+                //find equal range: respect case, ignore Unicode normalization
+                auto itEndCase = std::find_if(itCase + 1, itEndEq, [&](const FileRef& fr) { return getUnicodeNormalForm(fr.ref->first) != getUnicodeNormalForm(itCase->ref->first); });
+                if (!tryMatchRange(itCase, itEndCase))
+                    for (auto itRaw = itCase; itRaw != itEndCase;)
+                    {
+                        //find equal range: respect case, respect Unicode normalization
+                        auto itEndRaw = std::find_if(itRaw + 1, itEndCase, [&](const FileRef& fr) { return fr.ref->first != itRaw->ref->first; });
+                        if (!tryMatchRange(itRaw, itEndRaw))
+                            std::for_each(itRaw, itEndRaw, [&](const FileRef& fr)
+                        {
+                            if (fr.leftSide)
+                                lo(*fr.ref);
+                            else
+                                ro(*fr.ref);
+                        });
+                        itRaw = itEndRaw;
+                    }
+                itCase = itEndCase;
+            }
+        it = itEndEq;
+    }
 }
 
 
@@ -757,7 +802,7 @@ void MergeSides::mergeTwoSides(const FolderContainer& lhs, const FolderContainer
 {
     using FileData = FolderContainer::FileList::value_type;
 
-    linearMerge(lhs.files, rhs.files,
+    matchFolders(lhs.files, rhs.files,
     [&](const FileData& fileLeft ) { FilePair& newItem = output.addSubFile< LEFT_SIDE>(fileLeft .first, fileLeft .second); checkFailedRead(newItem, errorMsg); }, //left only
     [&](const FileData& fileRight) { FilePair& newItem = output.addSubFile<RIGHT_SIDE>(fileRight.first, fileRight.second); checkFailedRead(newItem, errorMsg); }, //right only
 
@@ -776,7 +821,7 @@ void MergeSides::mergeTwoSides(const FolderContainer& lhs, const FolderContainer
     //-----------------------------------------------------------------------------------------------
     using SymlinkData = FolderContainer::SymlinkList::value_type;
 
-    linearMerge(lhs.symlinks, rhs.symlinks,
+    matchFolders(lhs.symlinks, rhs.symlinks,
     [&](const SymlinkData& symlinkLeft ) { SymlinkPair& newItem = output.addSubLink< LEFT_SIDE>(symlinkLeft .first, symlinkLeft .second); checkFailedRead(newItem, errorMsg); }, //left only
     [&](const SymlinkData& symlinkRight) { SymlinkPair& newItem = output.addSubLink<RIGHT_SIDE>(symlinkRight.first, symlinkRight.second); checkFailedRead(newItem, errorMsg); }, //right only
 
@@ -794,8 +839,8 @@ void MergeSides::mergeTwoSides(const FolderContainer& lhs, const FolderContainer
     //-----------------------------------------------------------------------------------------------
     using FolderData = FolderContainer::FolderList::value_type;
 
-    linearMerge(lhs.folders, rhs.folders,
-                [&](const FolderData& dirLeft) //left only
+    matchFolders(lhs.folders, rhs.folders,
+                 [&](const FolderData& dirLeft) //left only
     {
         FolderPair& newFolder = output.addSubFolder<LEFT_SIDE>(dirLeft.first, dirLeft.second.first);
         const Zstringw* errorMsgNew = checkFailedRead(newFolder, errorMsg);
@@ -814,7 +859,8 @@ void MergeSides::mergeTwoSides(const FolderContainer& lhs, const FolderContainer
         const Zstringw* errorMsgNew = checkFailedRead(newFolder, errorMsg);
 
         if (!errorMsgNew)
-            if (dirLeft.first != dirRight.first)
+            if (getUnicodeNormalForm(dirLeft.first) !=
+                getUnicodeNormalForm(dirRight.first))
                 newFolder.setCategoryDiffMetadata(getDescrDiffMetaShortnameCase(newFolder));
 
         mergeTwoSides(dirLeft.second.second, dirRight.second.second, errorMsgNew, newFolder); //recurse
@@ -836,7 +882,7 @@ void stripExcludedDirectories(ContainerObject& hierObj, const HardFilter& filter
 
     hierObj.refSubFolders().remove_if([&](FolderPair& folder)
     {
-        const bool included = filterProc.passDirFilter(folder.getPairRelativePath(), nullptr); //childItemMightMatch is false, child items were already excluded during scanning
+        const bool included = filterProc.passDirFilter(folder.getRelativePathAny(), nullptr); //childItemMightMatch is false, child items were already excluded during scanning
 
         if (!included) //falsify only! (e.g. might already be inactive due to read error!)
             folder.setActive(false);
@@ -867,15 +913,16 @@ std::shared_ptr<BaseFolderPair> ComparisonBuffer::performComparison(const Resolv
     const DirectoryValue* bufValueLeft  = getDirValue(fp.folderPathLeft);
     const DirectoryValue* bufValueRight = getDirValue(fp.folderPathRight);
 
-    std::map<Zstring, Zstringw, LessFilePath> failedReads; //base-relative paths or empty if read-error for whole base directory
+    std::map<ZstringNoCase, Zstringw> failedReads; //base-relative paths or empty if read-error for whole base directory
     {
-        auto append = [&](const std::map<Zstring, std::wstring, LessFilePath>& c)
+        auto append = [&](const std::map<Zstring, std::wstring>& c)
         {
-            for (const auto& item : c)
-                failedReads.emplace(item.first, copyStringTo<Zstringw>(item.second));
+            for (const auto& [relPath, errorMsg] : c)
+                failedReads.emplace(relPath, copyStringTo<Zstringw>(errorMsg));
         };
+
         //mix failedFolderReads with failedItemReads:
-        //mark directory errors already at directory-level (instead for child items only) to show on GUI! See "MergeSides"
+        //associate folder traversing errors with folder (instead of child items only) to show on GUI! See "MergeSides"
         //=> minor pessimization for "excludefilterFailedRead" which needlessly excludes parent folders, too
         if (bufValueLeft ) append(bufValueLeft ->failedFolderReads);
         if (bufValueRight) append(bufValueRight->failedFolderReads);
@@ -888,8 +935,8 @@ std::shared_ptr<BaseFolderPair> ComparisonBuffer::performComparison(const Resolv
     if (failedReads.find(Zstring()) != failedReads.end()) //empty path if read-error for whole base directory
         excludefilterFailedRead += Zstr("*\n");
     else
-        for (const auto& item : failedReads)
-            excludefilterFailedRead += item.first + Zstr("\n"); //exclude item AND (potential) child items!
+        for (const auto& [relPath, errorMsg] : failedReads)
+            excludefilterFailedRead += relPath.upperCase + Zstr("\n"); //exclude item AND (potential) child items!
 
     std::shared_ptr<BaseFolderPair> output = std::make_shared<BaseFolderPair>(fp.folderPathLeft,
                                                                               bufValueLeft != nullptr, //dir existence must be checked only once: available iff buffer entry exists!
@@ -939,9 +986,6 @@ void fff::logNonDefaultSettings(const XmlGlobalSettings& activeSettings, Process
     if (activeSettings.fileTimeTolerance != defaultSettings.fileTimeTolerance)
         changedSettingsMsg += L"\n    " + _("File time tolerance") + L" - " + numberTo<std::wstring>(activeSettings.fileTimeTolerance);
 
-    if (activeSettings.folderAccessTimeout != defaultSettings.folderAccessTimeout)
-        changedSettingsMsg += L"\n    " + _("Folder access timeout") + L" - " + numberTo<std::wstring>(activeSettings.folderAccessTimeout.count());
-
     if (activeSettings.runWithBackgroundPriority != defaultSettings.runWithBackgroundPriority)
         changedSettingsMsg += L"\n    " + _("Run with background priority") + L" - " + (activeSettings.runWithBackgroundPriority ? _("Enabled") : _("Disabled"));
 
@@ -960,7 +1004,6 @@ FolderComparison fff::compare(WarningDialogs& warnings,
                               int fileTimeTolerance,
                               bool allowUserInteraction,
                               bool runWithBackgroundPriority,
-                              std::chrono::seconds folderAccessTimeout,
                               bool createDirLocks,
                               std::unique_ptr<LockHolder>& dirLocks,
                               const std::vector<FolderPairCfg>& fpCfgList,
@@ -999,7 +1042,7 @@ FolderComparison fff::compare(WarningDialogs& warnings,
         callback.reportInfo(e.toString()); //throw X
     }
 
-    const ResolvedBaseFolders& resInfo = initializeBaseFolders(fpCfgList, deviceParallelOps, folderAccessTimeout, allowUserInteraction, warnings.warnFolderNotExisting, callback); //throw X
+    const ResolvedBaseFolders& resInfo = initializeBaseFolders(fpCfgList, deviceParallelOps, allowUserInteraction, warnings.warnFolderNotExisting, callback); //throw X
     //directory existence only checked *once* to avoid race conditions!
     if (resInfo.resolvedPairs.size() != fpCfgList.size())
         throw std::logic_error("Contract violation! " + std::string(__FILE__) + ":" + numberTo<std::string>(__LINE__));
@@ -1034,13 +1077,13 @@ FolderComparison fff::compare(WarningDialogs& warnings,
     {
         std::wstring msg;
 
-        for (const auto& w : workLoad)
-            if (std::optional<PathDependency> pd = getPathDependency(w.first.folderPathLeft,  *w.second.filter.nameFilter,
-                                                                     w.first.folderPathRight, *w.second.filter.nameFilter))
+        for (const auto& [folderPair, fpCfg] : workLoad)
+            if (std::optional<PathDependency> pd = getPathDependency(folderPair.folderPathLeft,  *fpCfg.filter.nameFilter,
+                                                                     folderPair.folderPathRight, *fpCfg.filter.nameFilter))
             {
                 msg += L"\n\n" +
-                       AFS::getDisplayPath(w.first.folderPathLeft) + L"\n" +
-                       AFS::getDisplayPath(w.first.folderPathRight);
+                       AFS::getDisplayPath(folderPair.folderPathLeft) + L"\n" +
+                       AFS::getDisplayPath(folderPair.folderPathRight);
                 if (!pd->relPath.empty())
                     msg += L"\n" + _("Exclude:") + L" " + utfTo<std::wstring>(FILE_NAME_SEPARATOR + pd->relPath + FILE_NAME_SEPARATOR);
             }
@@ -1068,12 +1111,12 @@ FolderComparison fff::compare(WarningDialogs& warnings,
         //------------------- fill directory buffer ---------------------------------------------------
         std::set<DirectoryKey> foldersToRead;
 
-        for (const auto& w : workLoad)
+        for (const auto& [folderPair, fpCfg] : workLoad)
         {
-            if (basefolderExisting(w.first.folderPathLeft)) //only traverse *currently existing* folders: at this point user is aware that non-ex + empty string are seen as empty folder!
-                foldersToRead.emplace(DirectoryKey({ w.first.folderPathLeft, w.second.filter.nameFilter, w.second.handleSymlinks }));
-            if (basefolderExisting(w.first.folderPathRight))
-                foldersToRead.emplace(DirectoryKey({ w.first.folderPathRight, w.second.filter.nameFilter, w.second.handleSymlinks }));
+            if (basefolderExisting(folderPair.folderPathLeft)) //only traverse *currently existing* folders: at this point user is aware that non-ex + empty string are seen as empty folder!
+                foldersToRead.emplace(DirectoryKey({ folderPair.folderPathLeft, fpCfg.filter.nameFilter, fpCfg.handleSymlinks }));
+            if (basefolderExisting(folderPair.folderPathRight))
+                foldersToRead.emplace(DirectoryKey({ folderPair.folderPathRight, fpCfg.filter.nameFilter, fpCfg.handleSymlinks }));
         }
 
         FolderComparison output;
@@ -1087,21 +1130,21 @@ FolderComparison fff::compare(WarningDialogs& warnings,
 
             //process binary comparison as one junk
             std::vector<std::pair<ResolvedFolderPair, FolderPairCfg>> workLoadByContent;
-            for (const auto& w : workLoad)
-                if (w.second.compareVar == CompareVariant::CONTENT)
-                    workLoadByContent.push_back(w);
+            for (const auto& [folderPair, fpCfg] : workLoad)
+                if (fpCfg.compareVar == CompareVariant::CONTENT)
+                    workLoadByContent.push_back({ folderPair, fpCfg });
 
             std::list<std::shared_ptr<BaseFolderPair>> outputByContent = cmpBuff.compareByContent(workLoadByContent);
 
             //write output in expected order
-            for (const auto& w : workLoad)
-                switch (w.second.compareVar)
+            for (const auto& [folderPair, fpCfg] : workLoad)
+                switch (fpCfg.compareVar)
                 {
                     case CompareVariant::TIME_SIZE:
-                        output.push_back(cmpBuff.compareByTimeSize(w.first, w.second));
+                        output.push_back(cmpBuff.compareByTimeSize(folderPair, fpCfg));
                         break;
                     case CompareVariant::SIZE:
-                        output.push_back(cmpBuff.compareBySize(w.first, w.second));
+                        output.push_back(cmpBuff.compareBySize(folderPair, fpCfg));
                         break;
                     case CompareVariant::CONTENT:
                         assert(!outputByContent.empty());
diff --git a/FreeFileSync/Source/base/comparison.h b/FreeFileSync/Source/base/comparison.h
index 4c93a3ba..b956019b 100755
--- a/FreeFileSync/Source/base/comparison.h
+++ b/FreeFileSync/Source/base/comparison.h
@@ -55,7 +55,6 @@ FolderComparison compare(WarningDialogs& warnings,
                          int fileTimeTolerance,
                          bool allowUserInteraction,
                          bool runWithBackgroundPriority,
-                         std::chrono::seconds folderAccessTimeout,
                          bool createDirLocks,
                          std::unique_ptr<LockHolder>& dirLocks, //out
                          const std::vector<FolderPairCfg>& fpCfgList,
diff --git a/FreeFileSync/Source/base/db_file.cpp b/FreeFileSync/Source/base/db_file.cpp
index 5945918c..2dc88402 100755
--- a/FreeFileSync/Source/base/db_file.cpp
+++ b/FreeFileSync/Source/base/db_file.cpp
@@ -182,7 +182,7 @@ public:
         {
             try
             {
-                /* Zlib: optimal level - testcase 1 million files
+                /* Zlib: optimal level - test case 1 million files
                 level|size [MB]|time [ms]
                   0    49.54      272 (uncompressed)
                   1    14.53     1013
@@ -552,19 +552,16 @@ private:
 
     void recurse(const ContainerObject& hierObj, InSyncFolder& dbFolder)
     {
-        process(hierObj.refSubFiles  (), hierObj.getPairRelativePath(), dbFolder.files);
-        process(hierObj.refSubLinks  (), hierObj.getPairRelativePath(), dbFolder.symlinks);
-        process(hierObj.refSubFolders(), hierObj.getPairRelativePath(), dbFolder.folders);
+        process(hierObj.refSubFiles  (), hierObj.getRelativePathAny(), dbFolder.files);
+        process(hierObj.refSubLinks  (), hierObj.getRelativePathAny(), dbFolder.symlinks);
+        process(hierObj.refSubFolders(), hierObj.getRelativePathAny(), dbFolder.folders);
     }
 
     template <class M, class V>
     static V& mapAddOrUpdate(M& map, const Zstring& key, V&& value)
     {
-#if defined ZEN_LINUX && !defined __cpp_lib_map_try_emplace
-        auto rv = map.emplace(key, value); //C++11 emplace will move r-value arguments => don't use std::forward!
-#else //C++17's map::try_emplace() is faster than map::emplace() if key is already existing
-        auto rv = map.try_emplace(key, std::forward<V>(value)); //and does NOT MOVE r-value arguments in this case!
-#endif
+        //C++17's map::try_emplace() is faster than map::emplace() if key is already existing
+        auto rv = map.try_emplace(key, std::forward<V>(value)); //and does NOT MOVE r-value arguments unlike map::emplace()!
         if (rv.second)
             return rv.first->second;
 
@@ -582,12 +579,12 @@ private:
                 {
                     //Caveat: If FILE_EQUAL, we *implicitly* assume equal left and right short names matching case: InSyncFolder's mapping tables use short name as a key!
                     //This makes us silently dependent from code in algorithm.h!!!
-                    assert(file.getItemName<LEFT_SIDE>() == file.getItemName<RIGHT_SIDE>());
+                    assert(getUnicodeNormalForm(file.getItemName<LEFT_SIDE>()) == getUnicodeNormalForm(file.getItemName<RIGHT_SIDE>()));
                     //this should be taken for granted:
                     assert(file.getFileSize<LEFT_SIDE>() == file.getFileSize<RIGHT_SIDE>());
 
                     //create or update new "in-sync" state
-                    InSyncFile& dbFile = mapAddOrUpdate(dbFiles, file.getPairItemName(),
+                    InSyncFile& dbFile = mapAddOrUpdate(dbFiles, file.getItemNameAny(),
                                                         InSyncFile(InSyncDescrFile(file.getLastWriteTime< LEFT_SIDE>(),
                                                                                    file.getFileId       < LEFT_SIDE>()),
                                                                    InSyncDescrFile(file.getLastWriteTime<RIGHT_SIDE>(),
@@ -598,7 +595,7 @@ private:
                 }
                 else //not in sync: preserve last synchronous state
                 {
-                    auto it = dbFiles.find(file.getPairItemName());
+                    auto it = dbFiles.find(file.getItemNameAny());
                     if (it != dbFiles.end())
                         toPreserve.insert(&it->second);
                 }
@@ -625,10 +622,10 @@ private:
             {
                 if (symlink.getLinkCategory() == SYMLINK_EQUAL) //data in sync: write current state
                 {
-                    assert(symlink.getItemName<LEFT_SIDE>() == symlink.getItemName<RIGHT_SIDE>());
+                    assert(getUnicodeNormalForm(symlink.getItemName<LEFT_SIDE>()) == getUnicodeNormalForm(symlink.getItemName<RIGHT_SIDE>()));
 
                     //create or update new "in-sync" state
-                    InSyncSymlink& dbSymlink = mapAddOrUpdate(dbSymlinks, symlink.getPairItemName(),
+                    InSyncSymlink& dbSymlink = mapAddOrUpdate(dbSymlinks, symlink.getItemNameAny(),
                                                               InSyncSymlink(InSyncDescrLink(symlink.getLastWriteTime<LEFT_SIDE>()),
                                                                             InSyncDescrLink(symlink.getLastWriteTime<RIGHT_SIDE>()),
                                                                             activeCmpVar_));
@@ -636,7 +633,7 @@ private:
                 }
                 else //not in sync: preserve last synchronous state
                 {
-                    auto it = dbSymlinks.find(symlink.getPairItemName());
+                    auto it = dbSymlinks.find(symlink.getItemNameAny());
                     if (it != dbSymlinks.end())
                         toPreserve.insert(&it->second);
                 }
@@ -663,10 +660,10 @@ private:
                 {
                     case DIR_EQUAL:
                     {
-                        assert(folder.getItemName<LEFT_SIDE>() == folder.getItemName<RIGHT_SIDE>());
+                        assert(getUnicodeNormalForm(folder.getItemName<LEFT_SIDE>()) == getUnicodeNormalForm(folder.getItemName<RIGHT_SIDE>()));
 
                         //update directory entry only (shallow), but do *not touch* exising child elements!!!
-                        const Zstring& key = folder.getPairItemName();
+                        const Zstring& key = folder.getItemNameAny();
                         auto insertResult = dbFolders.emplace(key, InSyncFolder(InSyncFolder::DIR_STATUS_IN_SYNC)); //get or create
                         auto it = insertResult.first;
 
@@ -684,7 +681,7 @@ private:
                         //Example: directories on left and right differ in case while sub-files are equal
                     {
                         //reuse last "in-sync" if available or insert strawman entry (do not try to update and thereby remove child elements!!!)
-                        InSyncFolder& dbFolder = dbFolders.emplace(folder.getPairItemName(), InSyncFolder(InSyncFolder::DIR_STATUS_STRAW_MAN)).first->second;
+                        InSyncFolder& dbFolder = dbFolders.emplace(folder.getItemNameAny(), InSyncFolder(InSyncFolder::DIR_STATUS_STRAW_MAN)).first->second;
                         toPreserve.insert(&dbFolder);
                         recurse(folder, dbFolder); //unconditional recursion without filter check! => no problem since "childItemMightMatch" is optional!!!
                     }
@@ -694,7 +691,7 @@ private:
                     case DIR_LEFT_SIDE_ONLY:
                     case DIR_RIGHT_SIDE_ONLY:
                     {
-                        auto it = dbFolders.find(folder.getPairItemName());
+                        auto it = dbFolders.find(folder.getItemNameAny());
                         if (it != dbFolders.end())
                         {
                             toPreserve.insert(&it->second);
@@ -926,11 +923,11 @@ void fff::saveLastSynchronousState(const BaseFolderPair& baseFolder, const std::
 
     //operation finished: rename temp files -> this should work (almost) transactionally:
     //if there were no write access, creation of temp files would have failed
-    AFS::removeFileIfExists(dbPathLeft);        //throw FileError
-    AFS::renameItem(dbPathLeftTmp, dbPathLeft); //throw FileError, (ErrorDifferentVolume)
+    AFS::removeFileIfExists(dbPathLeft);               //throw FileError
+    AFS::moveAndRenameItem(dbPathLeftTmp, dbPathLeft); //throw FileError, (ErrorDifferentVolume)
     guardTmpL.dismiss();
 
-    AFS::removeFileIfExists(dbPathRight);         //
-    AFS::renameItem(dbPathRightTmp, dbPathRight); //
+    AFS::removeFileIfExists(dbPathRight);                //
+    AFS::moveAndRenameItem(dbPathRightTmp, dbPathRight); //
     guardTmpR.dismiss();
 }
diff --git a/FreeFileSync/Source/base/db_file.h b/FreeFileSync/Source/base/db_file.h
index 17409c2b..ebbb0c01 100755
--- a/FreeFileSync/Source/base/db_file.h
+++ b/FreeFileSync/Source/base/db_file.h
@@ -75,19 +75,19 @@ struct InSyncFolder
     SymlinkList symlinks; //non-followed symlinks
 
     //convenience
-    InSyncFolder& addFolder(const Zstring& shortName, InSyncStatus st)
+    InSyncFolder& addFolder(const Zstring& folderName, InSyncStatus st)
     {
-        return folders.emplace(shortName, InSyncFolder(st)).first->second;
+        return folders.emplace(folderName, InSyncFolder(st)).first->second;
     }
 
-    void addFile(const Zstring& shortName, const InSyncDescrFile& dataL, const InSyncDescrFile& dataR, CompareVariant cmpVar, uint64_t fileSize)
+    void addFile(const Zstring& fileName, const InSyncDescrFile& dataL, const InSyncDescrFile& dataR, CompareVariant cmpVar, uint64_t fileSize)
     {
-        files.emplace(shortName, InSyncFile(dataL, dataR, cmpVar, fileSize));
+        files.emplace(fileName, InSyncFile(dataL, dataR, cmpVar, fileSize));
     }
 
-    void addSymlink(const Zstring& shortName, const InSyncDescrLink& dataL, const InSyncDescrLink& dataR, CompareVariant cmpVar)
+    void addSymlink(const Zstring& linkName, const InSyncDescrLink& dataL, const InSyncDescrLink& dataR, CompareVariant cmpVar)
     {
-        symlinks.emplace(shortName, InSyncSymlink(dataL, dataR, cmpVar));
+        symlinks.emplace(linkName, InSyncSymlink(dataL, dataR, cmpVar));
     }
 };
 
diff --git a/FreeFileSync/Source/base/dir_exist_async.h b/FreeFileSync/Source/base/dir_exist_async.h
index acd79a69..c445a665 100755
--- a/FreeFileSync/Source/base/dir_exist_async.h
+++ b/FreeFileSync/Source/base/dir_exist_async.h
@@ -16,6 +16,8 @@
 
 namespace fff
 {
+const int DEFAULT_FOLDER_ACCESS_TIME_OUT_SEC = 20; //consider CD-ROM insert or hard disk spin up time from sleep
+
 namespace
 {
 //directory existence checking may hang for non-existent network drives => run asynchronously and update UI!
@@ -30,8 +32,7 @@ struct FolderStatus
 };
 
 FolderStatus getFolderStatusNonBlocking(const std::set<AbstractPath>& folderPaths, const std::map<AbstractPath, size_t>& deviceParallelOps,
-                                        std::chrono::seconds folderAccessTimeout, bool allowUserInteraction,
-                                        ProcessCallback& procCallback  /*throw X*/)
+                                        bool allowUserInteraction, ProcessCallback& procCallback  /*throw X*/)
 {
     using namespace zen;
 
@@ -45,20 +46,19 @@ FolderStatus getFolderStatusNonBlocking(const std::set<AbstractPath>& folderPath
     std::vector<std::pair<AbstractPath, std::future<bool>>> futureInfo;
 
     std::vector<ThreadGroup<std::packaged_task<bool()>>> perDeviceThreads;
-    for (const auto& item : perDevicePaths)
+    for (const auto& [rootPath, deviceFolderPaths] : perDevicePaths)
     {
-        const AbstractPath& rootPath = item.first;
         const size_t parallelOps = getDeviceParallelOps(deviceParallelOps, rootPath);
 
         perDeviceThreads.emplace_back(parallelOps, "DirExist: " + utfTo<std::string>(AFS::getDisplayPath(rootPath)));
         auto& threadGroup = perDeviceThreads.back();
         threadGroup.detach(); //don't wait on threads hanging longer than "folderAccessTimeout"
 
-        for (const AbstractPath& folderPath : item.second)
+        for (const AbstractPath& folderPath : deviceFolderPaths)
         {
             std::packaged_task<bool()> pt([folderPath, allowUserInteraction] //AbstractPath is thread-safe like an int! :)
             {
-                //1. login to network share, open FTP connection, ect.
+                //1. login to network share, open FTP connection, etc.
                 AFS::connectNetworkFolder(folderPath, allowUserInteraction); //throw FileError
 
                 //2. check dir existence
@@ -77,30 +77,31 @@ FolderStatus getFolderStatusNonBlocking(const std::set<AbstractPath>& folderPath
 
     FolderStatus output;
 
-    for (auto& fi : futureInfo)
+    for (auto& [folderPath, future] : futureInfo)
     {
-        const std::wstring& displayPathFmt = fmtPath(AFS::getDisplayPath(fi.first));
+        const std::wstring& displayPathFmt = fmtPath(AFS::getDisplayPath(folderPath));
 
         procCallback.reportStatus(replaceCpy(_("Searching for folder %x..."), L"%x", displayPathFmt)); //throw X
 
-        while (std::chrono::steady_clock::now() < startTime + folderAccessTimeout &&
-               fi.second.wait_for(UI_UPDATE_INTERVAL / 2) != std::future_status::ready)
+        const int deviceTimeOut = AFS::geAccessTimeout(folderPath); //0 if no timeout in force
+        const auto timeoutTime = startTime + std::chrono::seconds(deviceTimeOut > 0 ? deviceTimeOut : DEFAULT_FOLDER_ACCESS_TIME_OUT_SEC);
+
+        while (std::chrono::steady_clock::now() < timeoutTime &&
+               future.wait_for(UI_UPDATE_INTERVAL / 2) != std::future_status::ready)
             procCallback.requestUiRefresh(); //throw X
 
-        if (isReady(fi.second))
-        {
+        if (!isReady(future))
+            output.failedChecks.emplace(folderPath, FileError(replaceCpy(_("Timeout while searching for folder %x."), L"%x", displayPathFmt)));
+        else
             try
             {
                 //call future::get() only *once*! otherwise: undefined behavior!
-                if (fi.second.get()) //throw FileError
-                    output.existing.insert(fi.first);
+                if (future.get()) //throw FileError
+                    output.existing.insert(folderPath);
                 else
-                    output.notExisting.insert(fi.first);
+                    output.notExisting.insert(folderPath);
             }
-            catch (const FileError& e) { output.failedChecks.emplace(fi.first, e); }
-        }
-        else
-            output.failedChecks.emplace(fi.first, FileError(replaceCpy(_("Timeout while searching for folder %x."), L"%x", displayPathFmt)));
+            catch (const FileError& e) { output.failedChecks.emplace(folderPath, e); }
     }
     return output;
 }
diff --git a/FreeFileSync/Source/base/dir_lock.cpp b/FreeFileSync/Source/base/dir_lock.cpp
index 161fb35e..86006337 100755
--- a/FreeFileSync/Source/base/dir_lock.cpp
+++ b/FreeFileSync/Source/base/dir_lock.cpp
@@ -80,8 +80,6 @@ Zstring abandonedLockDeletionName(const Zstring& lockFilePath) //make sure to NO
 }
 
 
-#if 0
-#endif
 
 
     using ProcessId = pid_t;
@@ -160,7 +158,7 @@ LockInformation getLockInfoFromCurrentProcess() //throw FileError
 LockInformation unserialize(MemoryStreamIn<ByteArray>& stream) //throw UnexpectedEndOfStreamError
 {
     char tmp[sizeof(LOCK_FORMAT_DESCR)] = {};
-    readArray(stream, &tmp, sizeof(tmp));                         //file format header
+    readArray(stream, &tmp, sizeof(tmp));                    //file format header
     const int lockFileVersion = readNumber<int32_t>(stream); //
 
     if (!std::equal(std::begin(tmp), std::end(tmp), std::begin(LOCK_FORMAT_DESCR)) ||
diff --git a/FreeFileSync/Source/base/fatal_error.h b/FreeFileSync/Source/base/fatal_error.h
new file mode 100755
index 00000000..a27e423b
--- /dev/null
+++ b/FreeFileSync/Source/base/fatal_error.h
@@ -0,0 +1,45 @@
+// *****************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under    *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0          *
+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
+// *****************************************************************************
+
+#ifndef ERROR_LOG_H_89734181783491324134
+#define ERROR_LOG_H_89734181783491324134
+
+#include <cassert>
+#include <zen/file_io.h>
+#include <zen/time.h>
+#include "ffs_paths.h"
+
+
+namespace fff
+{
+//write error message to a file (even with corrupted stack)- call in desperate situations when no other means of error handling is available
+void logFatalError(const std::string& msg); //noexcept
+
+
+
+
+
+
+
+
+
+//##################### implementation ############################
+inline
+void logFatalError(const std::string& msg) //noexcept
+{
+    using namespace zen;
+
+    assert(false); //this is stuff we like to debug
+    const std::string logEntry = "[" + formatTime<std::string>(FORMAT_DATE) + " " + formatTime<std::string>(FORMAT_TIME) + "] " + msg;
+    try
+    {
+        saveBinContainer(getConfigDirPathPf() + Zstr("LastError.log"), logEntry, nullptr /*notifyUnbufferedIO*/); //throw FileError
+    }
+    catch (FileError&) {}
+}
+}
+
+#endif //ERROR_LOG_H_89734181783491324134
diff --git a/FreeFileSync/Source/base/file_hierarchy.cpp b/FreeFileSync/Source/base/file_hierarchy.cpp
index 88f7f152..d6e65ebd 100755
--- a/FreeFileSync/Source/base/file_hierarchy.cpp
+++ b/FreeFileSync/Source/base/file_hierarchy.cpp
@@ -27,7 +27,7 @@ std::wstring fff::getShortDisplayNameForFolderPair(const AbstractPath& itemPathL
 
         const Zstring itemNameL = AFS::getItemName(tmpPathL);
         const Zstring itemNameR = AFS::getItemName(tmpPathR);
-        if (!strEqual(itemNameL, itemNameR, CmpNaturalSort())) //let's compare case-insensitively even on Linux!
+        if (!equalNoCase(itemNameL, itemNameR)) //let's compare case-insensitively even on Linux!
             break;
 
         tmpPathL = *parentPathL;
@@ -358,7 +358,7 @@ const wchar_t arrowRight[] = L"->";
 
 std::wstring fff::getCategoryDescription(const FileSystemObject& fsObj)
 {
-    const std::wstring footer = L"\n[" + utfTo<std::wstring>(fsObj. getPairItemName()) + L"]";
+    const std::wstring footer = L"\n[" + utfTo<std::wstring>(fsObj. getItemNameAny()) + L"]";
 
     const CompareFilesResult cmpRes = fsObj.getCategory();
     switch (cmpRes)
@@ -439,7 +439,7 @@ std::wstring fff::getSyncOpDescription(SyncOperation op)
 
 std::wstring fff::getSyncOpDescription(const FileSystemObject& fsObj)
 {
-    const std::wstring footer = L"\n[" + utfTo<std::wstring>(fsObj. getPairItemName()) + L"]";
+    const std::wstring footer = L"\n[" + utfTo<std::wstring>(fsObj. getItemNameAny()) + L"]";
 
     const SyncOperation op = fsObj.getSyncOperation();
     switch (op)
@@ -458,15 +458,16 @@ std::wstring fff::getSyncOpDescription(const FileSystemObject& fsObj)
         case SO_COPY_METADATA_TO_RIGHT:
             //harmonize with synchronization.cpp::FolderPairSyncer::synchronizeFileInt, ect!!
         {
-            Zstring shortNameOld = fsObj.getItemName<RIGHT_SIDE>();
-            Zstring shortNameNew = fsObj.getItemName< LEFT_SIDE>();
+            Zstring itemNameOld = fsObj.getItemName<RIGHT_SIDE>();
+            Zstring itemNameNew = fsObj.getItemName< LEFT_SIDE>();
             if (op == SO_COPY_METADATA_TO_LEFT)
-                std::swap(shortNameOld, shortNameNew);
+                std::swap(itemNameOld, itemNameNew);
 
-            if (shortNameOld != shortNameNew) //detected change in case
+            if (getUnicodeNormalForm(itemNameOld) !=
+                getUnicodeNormalForm(itemNameNew)) //detected change in case
                 return getSyncOpDescription(op) + L"\n" +
-                       fmtPath(shortNameOld) + L" " + arrowRight + L"\n" + //show short name only
-                       fmtPath(shortNameNew) /*+ footer -> redundant */;
+                       fmtPath(itemNameOld) + L" " + arrowRight + L"\n" + //show short name only
+                       fmtPath(itemNameNew) /*+ footer -> redundant */;
         }
         return getSyncOpDescription(op) + footer; //fallback
 
@@ -491,8 +492,8 @@ std::wstring fff::getSyncOpDescription(const FileSystemObject& fsObj)
 
                     //attention: ::SetWindowText() doesn't handle tab characters correctly in combination with certain file names, so don't use them
                     return getSyncOpDescription(op) + L"\n" +
-                           (equalFilePath(beforeLast(relSource, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE),
-                                          beforeLast(relTarget, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE)) ?
+                           (beforeLast(relSource, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE) ==
+                            beforeLast(relTarget, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE) ?
                             //detected pure "rename"
                             fmtPath(afterLast(relSource, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL)) + L" " + arrowRight + L"\n" + //show short name only
                             fmtPath(afterLast(relTarget, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL)) :
diff --git a/FreeFileSync/Source/base/file_hierarchy.h b/FreeFileSync/Source/base/file_hierarchy.h
index 0ea4a3bb..4d06f73b 100755
--- a/FreeFileSync/Source/base/file_hierarchy.h
+++ b/FreeFileSync/Source/base/file_hierarchy.h
@@ -107,9 +107,9 @@ std::wstring getShortDisplayNameForFolderPair(const AbstractPath& itemPathL, con
 struct FolderContainer
 {
     //------------------------------------------------------------------
-    using FolderList  = std::map<Zstring, std::pair<FolderAttributes, FolderContainer>, LessFilePath>; //
-    using FileList    = std::map<Zstring, FileAttributes,  LessFilePath>; //key: file name
-    using SymlinkList = std::map<Zstring, LinkAttributes,  LessFilePath>; //
+    using FolderList  = std::map<Zstring, std::pair<FolderAttributes, FolderContainer>>; //
+    using FileList    = std::map<Zstring, FileAttributes>; //key: raw file name, without any (Unicode) normalization, preserving original upper-/lower-case
+    using SymlinkList = std::map<Zstring, LinkAttributes>; //
     //------------------------------------------------------------------
 
     FolderContainer() = default;
@@ -123,7 +123,7 @@ struct FolderContainer
     void addSubFile(const Zstring& itemName, const FileAttributes& attr)
     {
         auto rv = files.emplace(itemName, attr);
-        if (!rv.second) //update entry if already existing (e.g. during folder traverser "retry") => does not handle different item name case (irrelvant!..)
+        if (!rv.second) //update entry if already existing (e.g. during folder traverser "retry")
             rv.first->second = attr;
     }
 
@@ -174,8 +174,7 @@ struct PathInformation //diamond-shaped inheritence!
 
     template <SelectedSide side> AbstractPath getAbstractPath() const;
     template <SelectedSide side> Zstring      getRelativePath() const; //get path relative to base sync dir (without leading/trailing FILE_NAME_SEPARATOR)
-
-    Zstring getPairRelativePath() const;
+    Zstring getRelativePathAny() const { return getRelativePathL(); } //side doesn't matter
 
 private:
     virtual AbstractPath getAbstractPathL() const = 0; //implemented by FileSystemObject + BaseFolderPair
@@ -191,8 +190,6 @@ template <> inline AbstractPath PathInformation::getAbstractPath<RIGHT_SIDE>() c
 template <> inline Zstring PathInformation::getRelativePath<LEFT_SIDE >() const { return getRelativePathL(); }
 template <> inline Zstring PathInformation::getRelativePath<RIGHT_SIDE>() const { return getRelativePathR(); }
 
-inline Zstring PathInformation::getPairRelativePath() const { return getRelativePathL(); } //side doesn't matter
-
 //------------------------------------------------------------------
 
 class ContainerObject : public virtual PathInformation
@@ -421,12 +418,12 @@ class FileSystemObject : public ObjectMgr<FileSystemObject>, public virtual Path
 public:
     virtual void accept(FSObjectVisitor& visitor) const = 0;
 
-    Zstring getPairItemName() const; //like getItemName() but without bias to which side is returned
     bool isPairEmpty() const; //true, if both sides are empty
+    template <SelectedSide side> bool isEmpty() const;
 
     //path getters always return valid values, even if isEmpty<side>()!
+    Zstring getItemNameAny() const; //like getItemName() but without bias to which side is returned
     template <SelectedSide side> Zstring getItemName() const; //case sensitive!
-    template <SelectedSide side> bool isEmpty() const;
 
     //comparison result
     CompareFilesResult getCategory() const { return cmpResult_; }
@@ -794,12 +791,12 @@ Zstring FileSystemObject::getItemName() const
     const Zstring& itemName = SelectParam<side>::ref(itemNameL_, itemNameR_); //empty if not existing
     if (!itemName.empty()) //avoid ternary-WTF! (implicit copy-constructor call!!!!!!)
         return itemName;
-    return SelectParam<OtherSide<side>::value>::ref(itemNameL_, itemNameR_); //empty if not existing
+    return SelectParam<OtherSide<side>::value>::ref(itemNameL_, itemNameR_);
 }
 
 
 inline
-Zstring FileSystemObject::getPairItemName() const
+Zstring FileSystemObject::getItemNameAny() const
 {
     return getItemName<LEFT_SIDE>(); //side doesn't matter
 }
diff --git a/FreeFileSync/Source/base/generate_logfile.cpp b/FreeFileSync/Source/base/generate_logfile.cpp
index cbad8a4c..dbb8e42a 100755
--- a/FreeFileSync/Source/base/generate_logfile.cpp
+++ b/FreeFileSync/Source/base/generate_logfile.cpp
@@ -77,7 +77,7 @@ void streamToLogFile(const ProcessSummary& summary, //throw FileError
                      const std::wstring& finalStatusLabel,
                      AFS::OutputStream& streamOut)
 {
-    auto fmtForTxtFile = [needLbReplace = !strEqual(LINE_BREAK, '\n')](const std::wstring& str)
+    auto fmtForTxtFile = [needLbReplace = !equalString(LINE_BREAK, '\n')](const std::wstring& str)
     {
         std::string utfStr = utfTo<std::string>(str);
         if (needLbReplace)
@@ -196,7 +196,7 @@ std::vector<LogFileInfo> getLogFiles(const AbstractPath& logFolderPath) //throw
         //"2013-09-15 015052.123 [Error].log"
         static_assert(TIME_STAMP_LENGTH == 21);
 
-        if (endsWith(fi.itemName, Zstr(".log"), CmpFilePath()))
+        if (endsWith(fi.itemName, Zstr(".log"))) //case-sensitive: e.g. ".LOG" is not from FFS, right?
         {
             auto tsBegin = fi.itemName.begin();
             auto tsEnd   = fi.itemName.end() - 4;
diff --git a/FreeFileSync/Source/base/hard_filter.cpp b/FreeFileSync/Source/base/hard_filter.cpp
index 1c735c85..dda78b6b 100755
--- a/FreeFileSync/Source/base/hard_filter.cpp
+++ b/FreeFileSync/Source/base/hard_filter.cpp
@@ -35,7 +35,12 @@ static_assert(FILE_NAME_SEPARATOR == '/');
 
 void addFilterEntry(const Zstring& filterPhrase, std::vector<Zstring>& masksFileFolder, std::vector<Zstring>& masksFolder)
 {
-    const Zstring& filterFmt = filterPhrase; //Linux DOES distinguish between upper/lower-case: nothing to do here
+    warn_static("3. ignore path separator => bug regarding copyFilterAddingExclusion() after failed directory reads when dir has path separator from other OS in name")
+
+    //normalize filter input: 1. ignore Unicode normalization form 2. ignore case 3. ignore path separator
+    Zstring filterFmt = makeUpperCopy(filterPhrase);
+    if constexpr (FILE_NAME_SEPARATOR != Zstr('/' )) replace(filterFmt, Zstr('/'),  FILE_NAME_SEPARATOR);
+    if constexpr (FILE_NAME_SEPARATOR != Zstr('\\')) replace(filterFmt, Zstr('\\'), FILE_NAME_SEPARATOR);
     /*
       phrase  | action
     +---------+--------
@@ -218,12 +223,12 @@ bool matchesMaskBegin(const Zstring& name, const std::vector<Zstring>& masks)
 }
 
 
-std::vector<Zstring> fff::splitByDelimiter(const Zstring& filterString)
+std::vector<Zstring> fff::splitByDelimiter(const Zstring& filterPhrase)
 {
     //delimiters may be FILTER_ITEM_SEPARATOR or '\n'
     std::vector<Zstring> output;
 
-    for (const Zstring& str : split(filterString, FILTER_ITEM_SEPARATOR, SplitType::SKIP_EMPTY)) //split by less common delimiter first (create few, large strings)
+    for (const Zstring& str : split(filterPhrase, FILTER_ITEM_SEPARATOR, SplitType::SKIP_EMPTY)) //split by less common delimiter first (create few, large strings)
         for (Zstring entry : split(str, Zstr('\n'), SplitType::SKIP_EMPTY))
         {
             trim(entry);
@@ -261,7 +266,9 @@ void NameFilter::addExclusion(const Zstring& excludePhrase)
 bool NameFilter::passFileFilter(const Zstring& relFilePath) const
 {
     assert(!startsWith(relFilePath, FILE_NAME_SEPARATOR));
-    const Zstring& pathFmt = relFilePath; //nothing to do here
+
+    //normalize input: 1. ignore Unicode normalization form 2. ignore case
+    const Zstring& pathFmt = makeUpperCopy(relFilePath);
 
     if (matchesMask<AnyMatch         >(pathFmt, excludeMasksFileFolder) || //either full match on file or partial match on any parent folder
         matchesMask<ParentFolderMatch>(pathFmt, excludeMasksFolder))       //partial match on any parent folder only
@@ -277,7 +284,8 @@ bool NameFilter::passDirFilter(const Zstring& relDirPath, bool* childItemMightMa
     assert(!startsWith(relDirPath, FILE_NAME_SEPARATOR));
     assert(!childItemMightMatch || *childItemMightMatch); //check correct usage
 
-    const Zstring& pathFmt = relDirPath; //nothing to do here
+    //normalize input: 1. ignore Unicode normalization form 2. ignore case
+    const Zstring& pathFmt = makeUpperCopy(relDirPath);
 
     if (matchesMask<AnyMatch>(pathFmt, excludeMasksFileFolder) ||
         matchesMask<AnyMatch>(pathFmt, excludeMasksFolder))
diff --git a/FreeFileSync/Source/base/hard_filter.h b/FreeFileSync/Source/base/hard_filter.h
index 5e1f1702..682c2502 100755
--- a/FreeFileSync/Source/base/hard_filter.h
+++ b/FreeFileSync/Source/base/hard_filter.h
@@ -62,7 +62,7 @@ HardFilter::FilterRef combineFilters(const HardFilter::FilterRef& first,
                                      const HardFilter::FilterRef& second);
 
 
-class NullFilter : public HardFilter  //no filtering at all
+class NullFilter : public HardFilter //no filtering at all
 {
 public:
     bool passFileFilter(const Zstring& relFilePath) const override { return true; }
@@ -75,7 +75,7 @@ private:
 };
 
 
-class NameFilter : public HardFilter  //standard filter by filepath
+class NameFilter : public HardFilter //filter by base-relative file path
 {
 public:
     NameFilter(const Zstring& includePhrase, const Zstring& excludePhrase);
@@ -93,7 +93,7 @@ private:
     bool cmpLessSameType(const HardFilter& other) const override;
 
     std::vector<Zstring> includeMasksFileFolder; //
-    std::vector<Zstring> includeMasksFolder;     //upper case (windows) + unique items by construction
+    std::vector<Zstring> includeMasksFolder;     //upper-case + Unicode-normalized by construction
     std::vector<Zstring> excludeMasksFileFolder; //
     std::vector<Zstring> excludeMasksFolder;     //
 };
@@ -235,7 +235,7 @@ HardFilter::FilterRef constructFilter(const Zstring& includePhrase,
 }
 
 
-std::vector<Zstring> splitByDelimiter(const Zstring& filterString); //keep external linkage for unit test
+std::vector<Zstring> splitByDelimiter(const Zstring& filterPhrase); //keep external linkage for unit test
 }
 
 #endif //HARD_FILTER_H_825780275842758345
diff --git a/FreeFileSync/Source/base/icon_buffer.cpp b/FreeFileSync/Source/base/icon_buffer.cpp
index a784f9e0..39b5459b 100755
--- a/FreeFileSync/Source/base/icon_buffer.cpp
+++ b/FreeFileSync/Source/base/icon_buffer.cpp
@@ -283,7 +283,7 @@ struct IconBuffer::Impl
     InterruptibleThread worker;
     //-------------------------
     //-------------------------
-    std::map<Zstring, wxBitmap, LessFilePath> extensionIcons; //no item count limit!? Test case C:\ ~ 3800 unique file extensions
+    std::map<Zstring, wxBitmap, LessAsciiNoCase> extensionIcons; //no item count limit!? Test case C:\ ~ 3800 unique file extensions
 };
 
 
diff --git a/FreeFileSync/Source/base/localization.cpp b/FreeFileSync/Source/base/localization.cpp
index 28f19e33..de1b7087 100755
--- a/FreeFileSync/Source/base/localization.cpp
+++ b/FreeFileSync/Source/base/localization.cpp
@@ -89,24 +89,23 @@ FFSTranslation::FFSTranslation(const Zstring& lngFilePath, wxLanguage langId) :
 
     pluralParser_ = std::make_unique<plural::PluralForm>(header.pluralDefinition); //throw plural::ParsingError
 
-    for (const auto& item : transUtf)
-    {
-        std::wstring original    = utfTo<std::wstring>(item.first);
-        std::wstring translation = utfTo<std::wstring>(item.second);
-
-        transMapping_.emplace(std::move(original), std::move(translation));
-    }
+    for (const auto& [original, translation] : transUtf)
+        transMapping_.emplace(utfTo<std::wstring>(original),
+                              utfTo<std::wstring>(translation));
 
-    for (const auto& item : transPluralUtf)
+    for (const auto& [singAndPlural, pluralForms] : transPluralUtf)
     {
-        std::wstring engSingular = utfTo<std::wstring>(item.first.first);
-        std::wstring engPlural   = utfTo<std::wstring>(item.first.second);
+        std::vector<std::wstring> transPluralForms;
+        for (const std::string& pf : pluralForms)
+            transPluralForms.push_back(utfTo<std::wstring>(pf));
 
-        std::vector<std::wstring> pluralForms;
-        for (const std::string& pf : item.second)
-            pluralForms.push_back(utfTo<std::wstring>(pf));
-
-        transMappingPl_.insert({ { std::move(engSingular), std::move(engPlural) }, std::move(pluralForms) });
+        transMappingPl_.insert(
+        {
+            {
+                utfTo<std::wstring>(singAndPlural.first),
+                utfTo<std::wstring>(singAndPlural.second)
+            },
+            std::move(transPluralForms) });
     }
 }
 
diff --git a/FreeFileSync/Source/base/lock_holder.h b/FreeFileSync/Source/base/lock_holder.h
index cfe6a4fb..d4e3371c 100755
--- a/FreeFileSync/Source/base/lock_holder.h
+++ b/FreeFileSync/Source/base/lock_holder.h
@@ -20,7 +20,7 @@ class LockHolder
 public:
     LockHolder(const std::set<Zstring, LessFilePath>& dirPathsExisting, //resolved paths
                bool& warnDirectoryLockFailed,
-               ProcessCallback& pcb)
+               ProcessCallback& pcb /*throw X*/)
     {
         using namespace zen;
 
@@ -40,10 +40,10 @@ public:
         {
             std::wstring msg = _("Cannot set directory locks for the following folders:");
 
-            for (const auto& fl : failedLocks)
+            for (const auto& [folderPath, error] : failedLocks)
             {
-                msg += L"\n\n" + fmtPath(fl.first);
-                msg += L"\n" + replaceCpy(fl.second.toString(), L"\n\n", L"\n");
+                msg += L"\n\n" + fmtPath(folderPath);
+                msg += L"\n" + replaceCpy(error.toString(), L"\n\n", L"\n");
             }
 
             pcb.reportWarning(msg, warnDirectoryLockFailed); //throw X
diff --git a/FreeFileSync/Source/base/parallel_scan.cpp b/FreeFileSync/Source/base/parallel_scan.cpp
index cc432462..9ffb5f67 100755
--- a/FreeFileSync/Source/base/parallel_scan.cpp
+++ b/FreeFileSync/Source/base/parallel_scan.cpp
@@ -116,18 +116,18 @@ DiskInfo retrieveDiskInfo(const Zstring& itemPath)
 /*
 PERF NOTE
 
---------------------------------------------
-|Testcase: Reading from two different disks|
---------------------------------------------
+---------------------------------------------
+|Test case: Reading from two different disks|
+---------------------------------------------
 Windows 7:
             1st(unbuffered) |2nd (OS buffered)
             ----------------------------------
 1 Thread:          57s      |        8s
 2 Threads:         39s      |        7s
 
---------------------------------------------------
-|Testcase: Reading two directories from same disk|
---------------------------------------------------
+---------------------------------------------------
+|Test case: Reading two directories from same disk|
+---------------------------------------------------
 Windows 7:                                        Windows XP:
             1st(unbuffered) |2nd (OS buffered)                   1st(unbuffered) |2nd (OS buffered)
             ----------------------------------                   ----------------------------------
@@ -278,8 +278,8 @@ private:
         {
             std::lock_guard<std::mutex> dummy(lockCurrentStatus_);
 
-            for (const auto& item : activeThreadIdxs_)
-                parallelOpsTotal += item.second;
+            for (const auto& [threadIdx, parallelOps] : activeThreadIdxs_)
+                parallelOpsTotal += parallelOps;
 
             filePath = currentFile_;
         }
@@ -319,8 +319,8 @@ struct TraverserConfig
     const HardFilter::FilterRef filter; //always bound!
     const SymLinkHandling handleSymlinks;
 
-    std::map<Zstring, std::wstring, LessFilePath>& failedDirReads;
-    std::map<Zstring, std::wstring, LessFilePath>& failedItemReads;
+    std::map<Zstring, std::wstring>& failedDirReads;
+    std::map<Zstring, std::wstring>& failedItemReads;
 
     AsyncCallback& acb;
     const int threadIdx;
@@ -543,18 +543,17 @@ void fff::parallelDeviceTraversal(const std::set<DirectoryKey>& foldersToRead,
     ZEN_ON_SCOPE_FAIL( for (InterruptibleThread& wt : worker) wt.interrupt(); ); //interrupt all first, then join
 
     //init worker threads
-    for (const auto& item : perDeviceFolders)
+    for (const auto& [rootPath, dirKeys] : perDeviceFolders)
     {
-        const AbstractPath& rootPath = item.first;
         const int threadIdx = static_cast<int>(worker.size());
         const size_t parallelOps = getDeviceParallelOps(deviceParallelOps, rootPath);
 
         std::map<DirectoryKey, DirectoryValue*> workload;
 
-        for (const DirectoryKey& key : item.second)
+        for (const DirectoryKey& key : dirKeys)
             workload.emplace(key, &output[key]); //=> DirectoryValue* unshared for lock-free worker-thread access
 
-        worker.emplace_back([rootPath, workload, threadIdx, &acb, parallelOps]() mutable
+        worker.emplace_back([rootPath = rootPath /*clang bug :>*/, workload, threadIdx, &acb, parallelOps]() mutable
         {
             setCurrentThreadName(("Comp Worker[" + numberTo<std::string>(threadIdx) + "]").c_str());
 
@@ -565,11 +564,11 @@ void fff::parallelDeviceTraversal(const std::set<DirectoryKey>& foldersToRead,
 
             AFS::TraverserWorkload travWorkload;
 
-            for (auto& wl : workload)
+            for (auto& [folderKey, folderVal] : workload)
             {
-                const std::vector<Zstring> relPath = split(AFS::getRootRelativePath(wl.first.folderPath), FILE_NAME_SEPARATOR, SplitType::SKIP_EMPTY);
-                assert(AFS::getRootPath(wl.first.folderPath) == rootPath);
-                travWorkload.emplace_back(relPath, std::make_shared<BaseDirCallback>(wl.first, *wl.second, acb, threadIdx, lastReportTime));
+                const std::vector<Zstring> relPath = split(AFS::getRootRelativePath(folderKey.folderPath), FILE_NAME_SEPARATOR, SplitType::SKIP_EMPTY);
+                assert(AFS::getRootPath(folderKey.folderPath) == rootPath);
+                travWorkload.emplace_back(relPath, std::make_shared<BaseDirCallback>(folderKey, *folderVal, acb, threadIdx, lastReportTime));
             }
             AFS::traverseFolderRecursive(rootPath, travWorkload, parallelOps); //throw ThreadInterruption
         });
diff --git a/FreeFileSync/Source/base/parallel_scan.h b/FreeFileSync/Source/base/parallel_scan.h
index bbe1071f..dbb0c1d9 100755
--- a/FreeFileSync/Source/base/parallel_scan.h
+++ b/FreeFileSync/Source/base/parallel_scan.h
@@ -44,10 +44,10 @@ struct DirectoryValue
     FolderContainer folderCont;
 
     //relative paths (or empty string for root) for directories that could not be read (completely), e.g. access denied, or temporary network drop
-    std::map<Zstring, std::wstring, LessFilePath> failedFolderReads; //with corresponding error message
+    std::map<Zstring, std::wstring> failedFolderReads; //with corresponding error message
 
     //relative paths (never empty) for failure to read single file/dir/symlink with corresponding error message
-    std::map<Zstring, std::wstring, LessFilePath> failedItemReads;
+    std::map<Zstring, std::wstring> failedItemReads;
 };
 
 
diff --git a/FreeFileSync/Source/base/parse_lng.h b/FreeFileSync/Source/base/parse_lng.h
index b48af8b2..c282c2de 100755
--- a/FreeFileSync/Source/base/parse_lng.h
+++ b/FreeFileSync/Source/base/parse_lng.h
@@ -127,7 +127,7 @@ public:
     template <class Function, class Function2>
     void visitItems(Function onTrans, Function2 onPluralTrans) const //onTrans takes (const TranslationMap::value_type&), onPluralTrans takes (const TranslationPluralMap::value_type&)
     {
-        for (const auto& item : sequence_)
+        for (const std::shared_ptr<Item>& item : sequence_)
             if (auto regular = dynamic_cast<const RegularItem*>(item.get()))
                 onTrans(regular->value);
             else if (auto plural = dynamic_cast<const PluralItem*>(item.get()))
@@ -183,8 +183,8 @@ struct Token
     };
 
     Token(Type t) : type(t) {}
-    Type type;
 
+    Type type;
     std::string text;
 };
 
@@ -196,19 +196,19 @@ public:
 
     using TokenMap = std::map<Token::Type, std::string>;
 
-    const TokenMap& getList() const { return tokens; }
+    const TokenMap& getList() const { return tokens_; }
 
     std::string text(Token::Type t) const
     {
-        auto it = tokens.find(t);
-        if (it != tokens.end())
+        auto it = tokens_.find(t);
+        if (it != tokens_.end())
             return it->second;
         assert(false);
         return std::string();
     }
 
 private:
-    const TokenMap tokens =
+    const TokenMap tokens_ =
     {
         //header information
         { Token::TK_HEADER_BEGIN,       "<header>" },
@@ -246,19 +246,19 @@ public:
             pos_ += zen::strLength(zen::BYTE_ORDER_MARK_UTF8);
     }
 
-    Token nextToken()
+    Token getNextToken()
     {
         //skip whitespace
-        pos_ = std::find_if(pos_, stream_.end(), [](char c) { return !zen::isWhiteSpace(c); });
+        pos_ = std::find_if(pos_, stream_.end(), std::not_fn(zen::isWhiteSpace<char>));
 
         if (pos_ == stream_.end())
             return Token(Token::TK_END);
 
-        for (const auto& token : tokens_.getList())
-            if (startsWith(token.second))
+        for (const auto& [tokenEnum, tokenString] : tokens_.getList())
+            if (startsWith(tokenString))
             {
-                pos_ += token.second.size();
-                return Token(token.first);
+                pos_ += tokenString.size();
+                return Token(tokenEnum);
             }
 
         //rest must be "text"
@@ -268,7 +268,7 @@ public:
 
         std::string text(itBegin, pos_);
 
-        normalize(text); //remove whitespace from end ect.
+        normalize(text); //remove whitespace from end etc.
 
         if (text.empty() && pos_ == stream_.end())
             return Token(Token::TK_END);
@@ -308,9 +308,7 @@ private:
 
     bool startsWith(const std::string& prefix) const
     {
-        if (stream_.end() - pos_ < static_cast<ptrdiff_t>(prefix.size()))
-            return false;
-        return std::equal(prefix.begin(), prefix.end(), pos_);
+        return zen::startsWith(zen::StringRef<const char>(pos_, stream_.end()), prefix);
     }
 
     static void normalize(std::string& text)
@@ -335,7 +333,7 @@ private:
 class LngParser
 {
 public:
-    LngParser(const std::string& fileStream) : scn_(fileStream), tk_(scn_.nextToken()) {}
+    LngParser(const std::string& fileStream) : scn_(fileStream), tk_(scn_.getNextToken()) {}
 
     void parse(TranslationMap& out, TranslationPluralMap& pluralOut, TransHeader& header)
     {
@@ -357,54 +355,54 @@ public:
 
     void parseHeader(TransHeader& header)
     {
-        consumeToken(Token::TK_HEADER_BEGIN);
+        consumeToken(Token::TK_HEADER_BEGIN); //throw ParsingError
 
-        consumeToken(Token::TK_LANG_NAME_BEGIN);
+        consumeToken(Token::TK_LANG_NAME_BEGIN); //throw ParsingError
         header.languageName = token().text;
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_LANG_NAME_END);
+        consumeToken(Token::TK_TEXT);          //throw ParsingError
+        consumeToken(Token::TK_LANG_NAME_END); //
 
-        consumeToken(Token::TK_TRANS_NAME_BEGIN);
+        consumeToken(Token::TK_TRANS_NAME_BEGIN); //throw ParsingError
         header.translatorName = token().text;
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_TRANS_NAME_END);
+        consumeToken(Token::TK_TEXT);           //throw ParsingError
+        consumeToken(Token::TK_TRANS_NAME_END); //
 
-        consumeToken(Token::TK_LOCALE_NAME_BEGIN);
+        consumeToken(Token::TK_LOCALE_NAME_BEGIN); //throw ParsingError
         header.localeName = token().text;
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_LOCALE_NAME_END);
+        consumeToken(Token::TK_TEXT);            //throw ParsingError
+        consumeToken(Token::TK_LOCALE_NAME_END); //
 
-        consumeToken(Token::TK_FLAG_FILE_BEGIN);
+        consumeToken(Token::TK_FLAG_FILE_BEGIN); //throw ParsingError
         header.flagFile = token().text;
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_FLAG_FILE_END);
+        consumeToken(Token::TK_TEXT);          //throw ParsingError
+        consumeToken(Token::TK_FLAG_FILE_END); //
 
-        consumeToken(Token::TK_PLURAL_COUNT_BEGIN);
+        consumeToken(Token::TK_PLURAL_COUNT_BEGIN); //throw ParsingError
         header.pluralCount = zen::stringTo<int>(token().text);
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_PLURAL_COUNT_END);
+        consumeToken(Token::TK_TEXT);             //throw ParsingError
+        consumeToken(Token::TK_PLURAL_COUNT_END); //
 
-        consumeToken(Token::TK_PLURAL_DEF_BEGIN);
+        consumeToken(Token::TK_PLURAL_DEF_BEGIN); //throw ParsingError
         header.pluralDefinition = token().text;
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_PLURAL_DEF_END);
+        consumeToken(Token::TK_TEXT);           //throw ParsingError
+        consumeToken(Token::TK_PLURAL_DEF_END); //
 
-        consumeToken(Token::TK_HEADER_END);
+        consumeToken(Token::TK_HEADER_END); //throw ParsingError
     }
 
 private:
     void parseRegular(TranslationMap& out, TranslationPluralMap& pluralOut, const plural::PluralFormInfo& pluralInfo)
     {
-        consumeToken(Token::TK_SRC_BEGIN);
+        consumeToken(Token::TK_SRC_BEGIN); //throw ParsingError
 
         if (token().type == Token::TK_PLURAL_BEGIN)
             return parsePlural(pluralOut, pluralInfo);
 
         std::string original = token().text;
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_SRC_END);
+        consumeToken(Token::TK_TEXT);    //throw ParsingError
+        consumeToken(Token::TK_SRC_END); //
 
-        consumeToken(Token::TK_TRG_BEGIN);
+        consumeToken(Token::TK_TRG_BEGIN); //throw ParsingError
         std::string translation;
         if (token().type == Token::TK_TEXT)
         {
@@ -412,7 +410,7 @@ private:
             nextToken();
         }
         validateTranslation(original, translation); //throw ParsingError
-        consumeToken(Token::TK_TRG_END);
+        consumeToken(Token::TK_TRG_END);            //
 
         out.emplace(original, translation);
     }
@@ -421,32 +419,32 @@ private:
     {
         //Token::TK_SRC_BEGIN already consumed
 
-        consumeToken(Token::TK_PLURAL_BEGIN);
+        consumeToken(Token::TK_PLURAL_BEGIN); //throw ParsingError
         std::string engSingular = token().text;
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_PLURAL_END);
+        consumeToken(Token::TK_TEXT);       //throw ParsingError
+        consumeToken(Token::TK_PLURAL_END); //
 
-        consumeToken(Token::TK_PLURAL_BEGIN);
+        consumeToken(Token::TK_PLURAL_BEGIN); //throw ParsingError
         std::string engPlural = token().text;
-        consumeToken(Token::TK_TEXT);
-        consumeToken(Token::TK_PLURAL_END);
+        consumeToken(Token::TK_TEXT);       //throw ParsingError
+        consumeToken(Token::TK_PLURAL_END); //
 
-        consumeToken(Token::TK_SRC_END);
+        consumeToken(Token::TK_SRC_END); //throw ParsingError
         const SingularPluralPair original(engSingular, engPlural);
 
-        consumeToken(Token::TK_TRG_BEGIN);
+        consumeToken(Token::TK_TRG_BEGIN); //throw ParsingError
 
         PluralForms pluralList;
         while (token().type == Token::TK_PLURAL_BEGIN)
         {
-            consumeToken(Token::TK_PLURAL_BEGIN);
+            consumeToken(Token::TK_PLURAL_BEGIN); //throw ParsingError
             std::string pluralForm = token().text;
-            consumeToken(Token::TK_TEXT);
-            consumeToken(Token::TK_PLURAL_END);
+            consumeToken(Token::TK_TEXT);       //throw ParsingError
+            consumeToken(Token::TK_PLURAL_END); //
             pluralList.push_back(pluralForm);
         }
         validateTranslation(original, pluralList, pluralInfo);
-        consumeToken(Token::TK_TRG_END);
+        consumeToken(Token::TK_TRG_END); //throw ParsingError
 
         pluralOut.emplace(original, pluralList);
     }
@@ -678,14 +676,9 @@ private:
     }
 
 
-    void nextToken() { tk_ = scn_.nextToken(); }
     const Token& token() const { return tk_; }
 
-    void consumeToken(Token::Type t) //throw ParsingError
-    {
-        expectToken(t); //throw ParsingError
-        nextToken();
-    }
+    void nextToken() { tk_ = scn_.getNextToken(); }
 
     void expectToken(Token::Type t) //throw ParsingError
     {
@@ -693,6 +686,12 @@ private:
             throw ParsingError({ L"Unexpected token", scn_.posRow(), scn_.posCol() });
     }
 
+    void consumeToken(Token::Type t) //throw ParsingError
+    {
+        expectToken(t); //throw ParsingError
+        nextToken();
+    }
+
     Scanner scn_;
     Token tk_;
 };
diff --git a/FreeFileSync/Source/base/parse_plural.h b/FreeFileSync/Source/base/parse_plural.h
index 8a9173e3..e735c421 100755
--- a/FreeFileSync/Source/base/parse_plural.h
+++ b/FreeFileSync/Source/base/parse_plural.h
@@ -208,22 +208,22 @@ class Scanner
 public:
     Scanner(const std::string& stream) : stream_(stream), pos_(stream_.begin()) {}
 
-    Token nextToken()
+    Token getNextToken() //throw ParsingError
     {
         //skip whitespace
-        pos_ = std::find_if(pos_, stream_.end(), [](char c) { return !zen::isWhiteSpace(c); });
+        pos_ = std::find_if(pos_, stream_.end(), std::not_fn(zen::isWhiteSpace<char>));
 
         if (pos_ == stream_.end())
             return Token::TK_END;
 
-        for (const auto& item : tokens_)
-            if (startsWith(item.first))
+        for (const auto& [tokenString, tokenEnum] : tokens_)
+            if (startsWith(tokenString))
             {
-                pos_ += item.first.size();
-                return Token(item.second);
+                pos_ += tokenString.size();
+                return Token(tokenEnum);
             }
 
-        auto digitEnd = std::find_if(pos_, stream_.end(), [](char c) { return !zen::isDigit(c); });
+        auto digitEnd = std::find_if(pos_, stream_.end(), std::not_fn(zen::isDigit<char>));
         if (pos_ == digitEnd)
             throw ParsingError(); //unknown token
 
@@ -235,9 +235,7 @@ public:
 private:
     bool startsWith(const std::string& prefix) const
     {
-        if (stream_.end() - pos_ < static_cast<ptrdiff_t>(prefix.size()))
-            return false;
-        return std::equal(prefix.begin(), prefix.end(), pos_);
+        return zen::startsWith(zen::StringRef<const char>(pos_, stream_.end()), prefix);
     }
 
     using TokenList = std::vector<std::pair<std::string, Token::Type>>;
@@ -271,7 +269,7 @@ class Parser
 public:
     Parser(const std::string& stream, int64_t& n) :
         scn_(stream),
-        tk_(scn_.nextToken()),
+        tk_(scn_.getNextToken()), //throw ParsingError
         n_(n) {}
 
     std::shared_ptr<Expr<int64_t>> parse() //throw ParsingError; return value always bound!
@@ -279,7 +277,7 @@ public:
         auto e = std::dynamic_pointer_cast<Expr<int64_t>>(parseExpression()); //throw ParsingError
         if (!e)
             throw ParsingError();
-        expectToken(Token::TK_END);
+        expectToken(Token::TK_END); //throw ParsingError
         return e;
     }
 
@@ -292,13 +290,12 @@ private:
 
         if (token().type == Token::TK_TERNARY_QUEST)
         {
-            nextToken();
+            nextToken(); //throw ParsingError
 
             auto ifExp   = std::dynamic_pointer_cast<Expr<bool>>(e);
             auto thenExp = std::dynamic_pointer_cast<Expr<int64_t>>(parseExpression()); //associativity: <-
 
-            expectToken(Token::TK_TERNARY_COLON);
-            nextToken();
+            consumeToken(Token::TK_TERNARY_COLON); //throw ParsingError
 
             auto elseExp = std::dynamic_pointer_cast<Expr<int64_t>>(parseExpression()); //
             if (!ifExp || !thenExp || !elseExp)
@@ -313,7 +310,7 @@ private:
         std::shared_ptr<Expression> e = parseLogicalAnd();
         while (token().type == Token::TK_OR) //associativity: ->
         {
-            nextToken();
+            nextToken(); //throw ParsingError
 
             std::shared_ptr<Expression> rhs = parseLogicalAnd();
             e = makeBiExp<std::logical_or<>, bool>(e, rhs); //throw ParsingError
@@ -326,7 +323,7 @@ private:
         std::shared_ptr<Expression> e = parseEquality();
         while (token().type == Token::TK_AND) //associativity: ->
         {
-            nextToken();
+            nextToken(); //throw ParsingError
             std::shared_ptr<Expression> rhs = parseEquality();
 
             e = makeBiExp<std::logical_and<>, bool>(e, rhs); //throw ParsingError
@@ -342,7 +339,7 @@ private:
         if (t == Token::TK_EQUAL || //associativity: n/a
             t == Token::TK_NOT_EQUAL)
         {
-            nextToken();
+            nextToken(); //throw ParsingError
             std::shared_ptr<Expression> rhs = parseRelational();
 
             if (t == Token::TK_EQUAL)     return makeBiExp<std::equal_to<>,     int64_t>(e, rhs); //throw ParsingError
@@ -361,7 +358,7 @@ private:
             t == Token::TK_GREATER    ||
             t == Token::TK_GREATER_EQUAL)
         {
-            nextToken();
+            nextToken(); //throw ParsingError
             std::shared_ptr<Expression> rhs = parseMultiplicative();
 
             if (t == Token::TK_LESS)          return makeBiExp<std::less         <>, int64_t>(e, rhs); //
@@ -378,7 +375,7 @@ private:
 
         while (token().type == Token::TK_MODULUS) //associativity: ->
         {
-            nextToken();
+            nextToken(); //throw ParsingError
             std::shared_ptr<Expression> rhs = parsePrimary();
 
             //"compile-time" check: n % 0
@@ -395,37 +392,44 @@ private:
     {
         if (token().type == Token::TK_VARIABLE_N)
         {
-            nextToken();
+            nextToken(); //throw ParsingError
             return std::make_shared<VariableNumberNExp>(n_);
         }
         else if (token().type == Token::TK_CONST_NUMBER)
         {
             const int64_t number = token().number;
-            nextToken();
+            nextToken(); //throw ParsingError
             return std::make_shared<ConstNumberExp>(number);
         }
         else if (token().type == Token::TK_BRACKET_LEFT)
         {
-            nextToken();
+            nextToken(); //throw ParsingError
             std::shared_ptr<Expression> e = parseExpression();
 
-            expectToken(Token::TK_BRACKET_RIGHT);
-            nextToken();
+            expectToken(Token::TK_BRACKET_RIGHT); //throw ParsingError
+            nextToken();                          //
             return e;
         }
         else
             throw ParsingError();
     }
 
-    void nextToken() { tk_ = scn_.nextToken(); }
     const Token& token() const { return tk_; }
 
+    void nextToken() { tk_ = scn_.getNextToken(); } //throw ParsingError
+
     void expectToken(Token::Type t) //throw ParsingError
     {
         if (token().type != t)
             throw ParsingError();
     }
 
+    void consumeToken(Token::Type t) //throw ParsingError
+    {
+        expectToken(t); //throw ParsingError
+        nextToken();
+    }
+
     Scanner scn_;
     Token tk_;
     int64_t& n_;
diff --git a/FreeFileSync/Source/base/perf_check.h b/FreeFileSync/Source/base/perf_check.h
index a00aae84..2e9ccc6d 100755
--- a/FreeFileSync/Source/base/perf_check.h
+++ b/FreeFileSync/Source/base/perf_check.h
@@ -9,8 +9,8 @@
 
 #include <map>
 #include <chrono>
+#include <optional>
 #include <string>
-#include <zen/legacy_compiler.h> //#includes <optional>
 
 
 namespace fff
diff --git a/FreeFileSync/Source/base/process_xml.cpp b/FreeFileSync/Source/base/process_xml.cpp
index da7fa2e7..e3d1b89f 100755
--- a/FreeFileSync/Source/base/process_xml.cpp
+++ b/FreeFileSync/Source/base/process_xml.cpp
@@ -8,7 +8,6 @@
 #include <zenxml/xml.h>
 #include <zen/file_access.h>
 #include <zen/file_io.h>
-#include <zen/xml_io.h>
 #include <zen/time.h>
 #include <wx/intl.h>
 #include "ffs_paths.h"
@@ -49,8 +48,8 @@ XmlType getXmlTypeNoThrow(const XmlDoc& doc) //throw()
 
 XmlType fff::getXmlType(const Zstring& filePath) //throw FileError
 {
-    //do NOT use zen::loadStream as it will needlessly load even huge files!
-    XmlDoc doc = loadXmlDocument(filePath); //throw FileError; quick exit if file is not an FFS XML
+    //quick exit if file is not an XML
+    XmlDoc doc = loadXml(filePath); //throw FileError
     return ::getXmlTypeNoThrow(doc);
 }
 
@@ -1020,8 +1019,8 @@ void readConfig(const XmlIn& in, SyncConfig& syncCfg, std::map<AbstractPath, siz
 
         if (syncCfg.versioningStyle == VersioningStyle::REPLACE)
         {
-            if (endsWith(syncCfg.versioningFolderPhrase, Zstr("/%timestamp%"),  CmpAsciiNoCase()) ||
-                endsWith(syncCfg.versioningFolderPhrase, Zstr("\\%timestamp%"), CmpAsciiNoCase()))
+            if (endsWithAsciiNoCase(syncCfg.versioningFolderPhrase, Zstr("/%timestamp%")) ||
+                endsWithAsciiNoCase(syncCfg.versioningFolderPhrase, Zstr("\\%timestamp%")))
             {
                 syncCfg.versioningFolderPhrase.resize(syncCfg.versioningFolderPhrase.size() - strLength(Zstr("/%timestamp%")));
                 syncCfg.versioningStyle = VersioningStyle::TIMESTAMP_FOLDER;
@@ -1101,8 +1100,8 @@ void readConfig(const XmlIn& in, LocalPairConfig& lpc, std::map<AbstractPath, si
     {
         auto getParallelOps = [&](const Zstring& folderPathPhrase, size_t& parallelOps)
         {
-            if (startsWith(folderPathPhrase, Zstr("sftp:"), CmpAsciiNoCase()) ||
-                startsWith(folderPathPhrase, Zstr( "ftp:"), CmpAsciiNoCase()))
+            if (startsWithAsciiNoCase(folderPathPhrase, Zstr("sftp:")) ||
+                startsWithAsciiNoCase(folderPathPhrase, Zstr( "ftp:")))
             {
                 for (const Zstring& optPhrase : split(folderPathPhrase, Zstr("|"), SplitType::SKIP_EMPTY))
                     if (startsWith(optPhrase, Zstr("con=")))
@@ -1129,7 +1128,7 @@ void readConfig(const XmlIn& in, LocalPairConfig& lpc, std::map<AbstractPath, si
     setParallelOps(lpc.folderPathPhraseRight, parallelOpsR);
 
     //TODO: remove after migration - 2016-07-24
-    auto ciReplace = [](Zstring& pathPhrase, const Zstring& oldTerm, const Zstring& newTerm) { pathPhrase = ciReplaceCpy(pathPhrase, oldTerm, newTerm); };
+    auto ciReplace = [](Zstring& pathPhrase, const Zstring& oldTerm, const Zstring& newTerm) { pathPhrase = replaceCpyAsciiNoCase(pathPhrase, oldTerm, newTerm); };
     ciReplace(lpc.folderPathPhraseLeft,  Zstr("%csidl_MyDocuments%"), Zstr("%csidl_Documents%"));
     ciReplace(lpc.folderPathPhraseLeft,  Zstr("%csidl_MyMusic%"    ), Zstr("%csidl_Music%"));
     ciReplace(lpc.folderPathPhraseLeft,  Zstr("%csidl_MyPictures%" ), Zstr("%csidl_Pictures%"));
@@ -1278,7 +1277,7 @@ void readConfig(const XmlIn& in, XmlGuiConfig& cfg, int formatVer)
             cfg.mainCfg.ignoreErrors = str == "Ignore";
 
         str = trimCpy(utfTo<std::string>(cfg.mainCfg.postSyncCommand));
-        if (strEqual(str, "Close progress dialog", CmpAsciiNoCase()))
+        if (equalAsciiNoCase(str, "Close progress dialog"))
             cfg.mainCfg.postSyncCommand.clear();
     }
 }
@@ -1355,7 +1354,7 @@ void readConfig(const XmlIn& in, XmlBatchConfig& cfg, int formatVer)
             cfg.mainCfg.ignoreErrors = str == "Ignore";
 
         str = trimCpy(utfTo<std::string>(cfg.mainCfg.postSyncCommand));
-        if (strEqual(str, "Close progress dialog", CmpAsciiNoCase()))
+        if (equalAsciiNoCase(str, "Close progress dialog"))
         {
             cfg.batchExCfg.autoCloseSummary = true;
             cfg.mainCfg.postSyncCommand.clear();
@@ -1363,7 +1362,7 @@ void readConfig(const XmlIn& in, XmlBatchConfig& cfg, int formatVer)
         else if (str == "rundll32.exe powrprof.dll,SetSuspendState Sleep" ||
                  str == "rundll32.exe powrprof.dll,SetSuspendState" ||
                  str == "systemctl suspend" ||
-                 str == "osascript -e \'tell application \"System Events\" to sleep\'")
+                 str == "osascript -e 'tell application \"System Events\" to sleep'")
         {
             cfg.batchExCfg.postSyncAction = PostSyncAction::SLEEP;
             cfg.mainCfg.postSyncCommand.clear();
@@ -1371,7 +1370,7 @@ void readConfig(const XmlIn& in, XmlBatchConfig& cfg, int formatVer)
         else if (str == "shutdown /s /t 60"  ||
                  str == "shutdown -s -t 60"  ||
                  str == "systemctl poweroff" ||
-                 str == "osascript -e \'tell application \"System Events\" to shut down\'")
+                 str == "osascript -e 'tell application \"System Events\" to shut down'")
         {
             cfg.batchExCfg.postSyncAction = PostSyncAction::SHUTDOWN;
             cfg.mainCfg.postSyncCommand.clear();
@@ -1396,7 +1395,6 @@ void readConfig(const XmlIn& in, XmlGlobalSettings& cfg, int formatVer)
     inGeneral["CopyLockedFiles"          ].attribute("Enabled", cfg.copyLockedFiles);
     inGeneral["CopyFilePermissions"      ].attribute("Enabled", cfg.copyFilePermissions);
     inGeneral["FileTimeTolerance"        ].attribute("Seconds", cfg.fileTimeTolerance);
-    inGeneral["FolderAccessTimeout"      ].attribute("Seconds", cfg.folderAccessTimeout);
     inGeneral["RunWithBackgroundPriority"].attribute("Enabled", cfg.runWithBackgroundPriority);
     inGeneral["LockDirectoriesDuringSync"].attribute("Enabled", cfg.createLockFile);
     inGeneral["VerifyCopiedFiles"        ].attribute("Enabled", cfg.verifyFileCopy);
@@ -1673,8 +1671,8 @@ void readConfig(const XmlIn& in, XmlGlobalSettings& cfg, int formatVer)
             if (inGui["ExternalApps"](extApps))
             {
                 cfg.gui.externalApps.clear();
-                for (const auto& item : extApps)
-                    cfg.gui.externalApps.push_back({ item.first, item.second });
+                for (const auto& [description, cmdLine] : extApps)
+                    cfg.gui.externalApps.push_back({ description, cmdLine });
             }
         }
         else
@@ -1683,7 +1681,7 @@ void readConfig(const XmlIn& in, XmlGlobalSettings& cfg, int formatVer)
 
     //TODO: remove macro migration after some time! 2016-06-30
     if (formatVer < 3)
-        for (auto& item : cfg.gui.externalApps)
+        for (ExternalApp& item : cfg.gui.externalApps)
         {
             replace(item.cmdLine, Zstr("%item2_path%"),   Zstr("%item_path2%"));
             replace(item.cmdLine, Zstr("%item_folder%"),  Zstr("%folder_path%"));
@@ -1703,7 +1701,7 @@ void readConfig(const XmlIn& in, XmlGlobalSettings& cfg, int formatVer)
             }
         }
     //TODO: remove macro migration after some time! 2016-07-18
-    for (auto& item : cfg.gui.externalApps)
+    for (ExternalApp& item : cfg.gui.externalApps)
         replace(item.cmdLine, Zstr("%item_folder%"),  Zstr("%folder_path%"));
 
     //last update check
@@ -1740,7 +1738,7 @@ int getConfigFormatVersion(const XmlDoc& doc)
 template <class ConfigType>
 void readConfig(const Zstring& filePath, XmlType type, ConfigType& cfg, int currentXmlFormatVer, std::wstring& warningMsg) //throw FileError
 {
-    XmlDoc doc = loadXmlDocument(filePath); //throw FileError
+    XmlDoc doc = loadXml(filePath); //throw FileError
 
     if (getXmlTypeNoThrow(doc) != type) //noexcept
         throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
@@ -1752,7 +1750,7 @@ void readConfig(const Zstring& filePath, XmlType type, ConfigType& cfg, int curr
 
     try
     {
-        checkForMappingErrors(in, filePath); //throw FileError
+        checkXmlMappingErrors(in, filePath); //throw FileError
 
         //(try to) migrate old configuration automatically
         if (formatVer < currentXmlFormatVer)
@@ -1795,7 +1793,7 @@ XmlCfg parseConfig(const XmlDoc& doc, const Zstring& filePath, int currentXmlFor
 
     try
     {
-        checkForMappingErrors(in, filePath); //throw FileError
+        checkXmlMappingErrors(in, filePath); //throw FileError
 
         //(try to) migrate old configuration if needed
         if (formatVer < currentXmlFormatVer)
@@ -1824,7 +1822,7 @@ void fff::readAnyConfig(const std::vector<Zstring>& filePaths, XmlGuiConfig& cfg
         const Zstring& filePath = *it;
         const bool firstItem = it == filePaths.begin(); //init all non-"mainCfg" settings with first config file
 
-        XmlDoc doc = loadXmlDocument(filePath); //throw FileError
+        XmlDoc doc = loadXml(filePath); //throw FileError
 
         switch (getXmlTypeNoThrow(doc))
         {
@@ -2041,7 +2039,6 @@ void writeConfig(const XmlGlobalSettings& cfg, XmlOut& out)
     outGeneral["CopyLockedFiles"          ].attribute("Enabled", cfg.copyLockedFiles);
     outGeneral["CopyFilePermissions"      ].attribute("Enabled", cfg.copyFilePermissions);
     outGeneral["FileTimeTolerance"        ].attribute("Seconds", cfg.fileTimeTolerance);
-    outGeneral["FolderAccessTimeout"      ].attribute("Seconds", cfg.folderAccessTimeout);
     outGeneral["RunWithBackgroundPriority"].attribute("Enabled", cfg.runWithBackgroundPriority);
     outGeneral["LockDirectoriesDuringSync"].attribute("Enabled", cfg.createLockFile);
     outGeneral["VerifyCopiedFiles"        ].attribute("Enabled", cfg.verifyFileCopy);
@@ -2167,7 +2164,7 @@ void writeConfig(const ConfigType& cfg, XmlType type, int xmlFormatVer, const Zs
     XmlOut out(doc);
     writeConfig(cfg, out);
 
-    saveXmlDocument(doc, filePath); //throw FileError
+    saveXml(doc, filePath); //throw FileError
 }
 }
 
@@ -2191,7 +2188,7 @@ void fff::writeConfig(const XmlGlobalSettings& cfg, const Zstring& filePath)
 
 std::wstring fff::extractJobName(const Zstring& cfgFilePath)
 {
-    const Zstring shortName = afterLast(cfgFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL);
-    const Zstring jobName   = beforeLast(shortName, Zstr('.'), IF_MISSING_RETURN_ALL);
+    const Zstring fileName = afterLast(cfgFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL);
+    const Zstring jobName  = beforeLast(fileName, Zstr('.'), IF_MISSING_RETURN_ALL);
     return utfTo<std::wstring>(jobName);
 }
diff --git a/FreeFileSync/Source/base/process_xml.h b/FreeFileSync/Source/base/process_xml.h
index 17cb884a..85777a5c 100755
--- a/FreeFileSync/Source/base/process_xml.h
+++ b/FreeFileSync/Source/base/process_xml.h
@@ -7,7 +7,6 @@
 #ifndef PROCESS_XML_H_28345825704254262435
 #define PROCESS_XML_H_28345825704254262435
 
-#include <zen/xml_io.h>
 #include <wx/gdicmn.h>
 #include "localization.h"
 #include "structures.h"
@@ -175,7 +174,6 @@ struct XmlGlobalSettings
     bool copyFilePermissions = false;
 
     int fileTimeTolerance = 2; //max. allowed file time deviation; < 0 means unlimited tolerance; default 2s: FAT vs NTFS
-    std::chrono::seconds folderAccessTimeout{20}; //consider CD-ROM insert or hard disk spin up time from sleep
     bool runWithBackgroundPriority = false;
     bool createLockFile = true;
     bool verifyFileCopy = false;
diff --git a/FreeFileSync/Source/base/resolve_path.cpp b/FreeFileSync/Source/base/resolve_path.cpp
index f8eae4d9..49699fa4 100755
--- a/FreeFileSync/Source/base/resolve_path.cpp
+++ b/FreeFileSync/Source/base/resolve_path.cpp
@@ -29,8 +29,8 @@ std::optional<Zstring> getEnvironmentVar(const Zstring& name)
     trim(value); //remove leading, trailing blanks
 
     //remove leading, trailing double-quotes
-    if (startsWith(value, Zstr('\"')) &&
-        endsWith  (value, Zstr('\"')) &&
+    if (startsWith(value, Zstr('"')) &&
+        endsWith  (value, Zstr('"')) &&
         value.length() >= 2)
         value = Zstring(value.c_str() + 1, value.length() - 2);
 
@@ -77,23 +77,24 @@ Zstring resolveRelativePath(const Zstring& relativePath)
 
 
 
+
 //returns value if resolved
 std::optional<Zstring> tryResolveMacro(const Zstring& macro) //macro without %-characters
 {
     //there exist environment variables named %TIME%, %DATE% so check for our internal macros first!
-    if (strEqual(macro, Zstr("time"), CmpAsciiNoCase()))
+    if (equalAsciiNoCase(macro, Zstr("time")))
         return formatTime<Zstring>(Zstr("%H%M%S"));
 
-    if (strEqual(macro, Zstr("date"), CmpAsciiNoCase()))
+    if (equalAsciiNoCase(macro, Zstr("date")))
         return formatTime<Zstring>(FORMAT_ISO_DATE);
 
-    if (strEqual(macro, Zstr("timestamp"), CmpAsciiNoCase()))
+    if (equalAsciiNoCase(macro, Zstr("timestamp")))
         return formatTime<Zstring>(Zstr("%Y-%m-%d %H%M%S")); //e.g. "2012-05-15 131513"
 
     Zstring timeStr;
     auto resolveTimePhrase = [&](const Zchar* phrase, const Zchar* format) -> bool
     {
-        if (!strEqual(macro, phrase, CmpAsciiNoCase()))
+        if (!equalAsciiNoCase(macro, phrase))
             return false;
 
         timeStr = formatTime<Zstring>(format);
@@ -188,12 +189,10 @@ void getDirectoryAliasesRecursive(const Zstring& pathPhrase, std::set<Zstring, L
         addEnvVar("HOME"); //Linux: /home/<user>  Mac: /Users/<user>
         //addEnvVar("USER");  -> any benefit?
         //substitute paths by symbolic names
-        for (const auto& item : macroList)
+        for (const auto& [macroName, macroPath] : macroList)
         {
-            const Zstring& macroName = item.first;
-            const Zstring& macroPath = item.second;
-
-            const Zstring pathSubst = ciReplaceCpy(pathPhrase, macroPath, MACRO_SEP + macroName + MACRO_SEP); //ci on Linux, too? okay
+            //should use a replaceCpy() that considers "local path" case-sensitivity (if only we had one...)
+            const Zstring pathSubst = replaceCpyAsciiNoCase(pathPhrase, macroPath, MACRO_SEP + macroName + MACRO_SEP);
             if (pathSubst != pathPhrase)
                 output.insert(pathSubst);
         }
diff --git a/FreeFileSync/Source/base/status_handler.h b/FreeFileSync/Source/base/status_handler.h
index 9a3c0948..59d5c80c 100755
--- a/FreeFileSync/Source/base/status_handler.h
+++ b/FreeFileSync/Source/base/status_handler.h
@@ -86,7 +86,7 @@ public:
     //implement parts of ProcessCallback
     void initNewPhase(int itemsTotal, int64_t bytesTotal, Phase phase) override //(throw X)
     {
-        assert(itemsTotal < 0 == bytesTotal < 0);
+        assert((itemsTotal < 0) == (bytesTotal < 0));
         currentPhase_ = phase;
         refStats(statsTotal_, currentPhase_) = { itemsTotal, bytesTotal };
     }
diff --git a/FreeFileSync/Source/base/status_handler_impl.h b/FreeFileSync/Source/base/status_handler_impl.h
index 21f108de..af578b82 100755
--- a/FreeFileSync/Source/base/status_handler_impl.h
+++ b/FreeFileSync/Source/base/status_handler_impl.h
@@ -131,9 +131,9 @@ public:
     void notifyTaskBegin(size_t prio) //noexcept
     {
         assert(!zen::runningMainThread());
-        assert(!getThreadStatus());
         const uint64_t threadId = zen::getThreadId();
         std::lock_guard<std::mutex> dummy(lockCurrentStatus_);
+        assert(!getThreadStatus());
 
         //const size_t taskIdx = [&]() -> size_t
         //{
@@ -160,7 +160,7 @@ public:
         const uint64_t threadId = zen::getThreadId();
         std::lock_guard<std::mutex> dummy(lockCurrentStatus_);
 
-        for (auto& sbp : statusByPriority_)
+        for (std::vector<ThreadStatus>& sbp : statusByPriority_)
             for (ThreadStatus& ts : sbp)
                 if (ts.threadId == threadId)
                 {
@@ -196,7 +196,7 @@ private:
         assert(!zen::runningMainThread());
         const uint64_t threadId = zen::getThreadId();
 
-        for (auto& sbp : statusByPriority_)
+        for (std::vector<ThreadStatus>& sbp : statusByPriority_)
             for (ThreadStatus& ts : sbp) //thread count is (hopefully) small enough so that linear search won't hurt perf
                 if (ts.threadId == threadId)
                     return &ts;
@@ -250,7 +250,7 @@ private:
 
             statusMsg = [&]
             {
-                for (const auto& sbp : statusByPriority_)
+                for (const std::vector<ThreadStatus>& sbp : statusByPriority_)
                     for (const ThreadStatus& ts : sbp)
                         if (!ts.statusMsg.empty())
                             return ts.statusMsg;
@@ -386,10 +386,7 @@ struct ParallelContext
     const AddTaskCallback& scheduleExtraTask; //throw ThreadInterruption
 };
 
-#ifdef __GNUC__ //ugly, but we won't put the function into a cpp nor make it inline
-    #pragma GCC diagnostic push
-    #pragma GCC diagnostic ignored "-Wunused-function"
-#endif
+
 namespace
 {
 void massParallelExecute(const std::vector<std::pair<AbstractPath, ParallelWorkItem>>& workload,
@@ -423,13 +420,12 @@ void massParallelExecute(const std::vector<std::pair<AbstractPath, ParallelWorkI
 
     //---------------------------------------------------------------------------------------------------------
     //Attention: carefully orchestrate access to deviceThreadGroups and its contained worker threads! e.g. synchronize potential access during ~DeviceThreadGroup!
-    for (const auto& devItems : perDeviceWorkload)
+    for (const auto& [rootPath, wl] : perDeviceWorkload)
     {
-        const AbstractPath& rootPath = devItems.first;
         const size_t parallelOps = getDeviceParallelOps(deviceParallelOps, rootPath);
         const size_t statusPrio = deviceThreadGroups.size();
 
-        auto scheduleExtraTask = [&acb, &deviceThreadGroupsShared, rootPath](const AfsPath& afsPath, const ParallelWorkItem& task)
+        auto scheduleExtraTask = [&acb, &deviceThreadGroupsShared, rootPath = rootPath /*clang bug :>*/](const AfsPath& afsPath, const ParallelWorkItem& task)
         {
             const AbstractPath& itemPath = AFS::appendRelPath(rootPath, afsPath.value);
 
@@ -459,12 +455,11 @@ void massParallelExecute(const std::vector<std::pair<AbstractPath, ParallelWorkI
     //[!] deviceThreadGroups is shared with worker threads from here on!
     ZEN_ON_SCOPE_EXIT(deviceThreadGroupsShared.access([&](auto*& deviceThreadGroupsPtr) { deviceThreadGroupsPtr = nullptr; }));
 
-    for (const auto& devItems : perDeviceWorkload)
+    for (const auto& [rootPath, wl] : perDeviceWorkload)
     {
-        const AbstractPath& rootPath = devItems.first;
         ThreadGroupContext& ctx = deviceThreadGroups.find(rootPath)->second; //exists after construction above!
 
-        for (const std::pair<AbstractPath, ParallelWorkItem>* item : devItems.second)
+        for (const std::pair<AbstractPath, ParallelWorkItem>* item : wl)
             ctx.threadGroup.run([&acb, statusPrio = ctx.statusPrio, &itemPath = item->first, &task = item->second, &scheduleExtraTask = ctx.scheduleExtraTask]
         {
             acb.notifyTaskBegin(statusPrio);
@@ -487,9 +482,6 @@ void massParallelExecute(const std::vector<std::pair<AbstractPath, ParallelWorkI
     acb.waitUntilDone(UI_UPDATE_INTERVAL / 2 /*every ~50 ms*/, callback); //throw X
 }
 }
-#ifdef __GNUC__
-    #pragma GCC diagnostic pop
-#endif
 
 //=====================================================================================================================
 
diff --git a/FreeFileSync/Source/base/structures.cpp b/FreeFileSync/Source/base/structures.cpp
index 19c39aac..e39084ea 100755
--- a/FreeFileSync/Source/base/structures.cpp
+++ b/FreeFileSync/Source/base/structures.cpp
@@ -605,8 +605,8 @@ MainConfiguration fff::merge(const std::vector<MainConfiguration>& mainCfgs)
 
     std::map<AbstractPath, size_t> mergedParallelOps;
     for (const MainConfiguration& mainCfg : mainCfgs)
-        for (const auto& item : mainCfg.deviceParallelOps)
-            mergedParallelOps[item.first] = std::max(mergedParallelOps[item.first], item.second);
+        for (const auto& [rootPath, parallelOps] : mainCfg.deviceParallelOps)
+            mergedParallelOps[rootPath] = std::max(mergedParallelOps[rootPath], parallelOps);
 
     //final assembly
     MainConfiguration cfgOut;
diff --git a/FreeFileSync/Source/base/synchronization.cpp b/FreeFileSync/Source/base/synchronization.cpp
index d55a57a8..25723ce2 100755
--- a/FreeFileSync/Source/base/synchronization.cpp
+++ b/FreeFileSync/Source/base/synchronization.cpp
@@ -124,7 +124,7 @@ void SyncStatistics::processFile(const FilePair& file)
             break;
 
         case SO_UNRESOLVED_CONFLICT:
-            conflictMsgs_.push_back({ file.getPairRelativePath(), file.getSyncOpConflict() });
+            conflictMsgs_.push_back({ file.getRelativePathAny(), file.getSyncOpConflict() });
             break;
 
         case SO_COPY_METADATA_TO_LEFT:
@@ -178,7 +178,7 @@ void SyncStatistics::processLink(const SymlinkPair& link)
             break;
 
         case SO_UNRESOLVED_CONFLICT:
-            conflictMsgs_.push_back({ link.getPairRelativePath(), link.getSyncOpConflict() });
+            conflictMsgs_.push_back({ link.getRelativePathAny(), link.getSyncOpConflict() });
             break;
 
         case SO_MOVE_LEFT_FROM:
@@ -217,7 +217,7 @@ void SyncStatistics::processFolder(const FolderPair& folder)
             break;
 
         case SO_UNRESOLVED_CONFLICT:
-            conflictMsgs_.push_back({ folder.getPairRelativePath(), folder.getSyncOpConflict() });
+            conflictMsgs_.push_back({ folder.getRelativePathAny(), folder.getSyncOpConflict() });
             break;
 
         case SO_OVERWRITE_LEFT:
@@ -497,8 +497,8 @@ bool removeSymlinkIfExists(const AbstractPath& ap, std::mutex& singleThread) //t
 { return parallelScope([ap] { return AFS::removeSymlinkIfExists(ap); /*throw FileError*/ }, singleThread); }
 
 inline
-void renameItem(const AbstractPath& apSource, const AbstractPath& apTarget, std::mutex& singleThread) //throw FileError, ErrorDifferentVolume
-{ parallelScope([apSource, apTarget] { AFS::renameItem(apSource, apTarget); /*throw FileError, ErrorDifferentVolume*/ }, singleThread); }
+void moveAndRenameItem(const AbstractPath& apSource, const AbstractPath& apTarget, std::mutex& singleThread) //throw FileError, ErrorDifferentVolume
+{ parallelScope([apSource, apTarget] { AFS::moveAndRenameItem(apSource, apTarget); /*throw FileError, ErrorDifferentVolume*/ }, singleThread); }
 
 inline
 AbstractPath getSymlinkResolvedPath(const AbstractPath& ap, std::mutex& singleThread) //throw FileError
@@ -733,6 +733,7 @@ void DeletionHandler::removeDirWithCallback(const AbstractPath& folderPath,//thr
                 statReporter.reportStatus(replaceCpy(statusText, L"%x", fmtPath(displayPath))); //throw ThreadInterruption
                 statReporter.reportDelta(1, 0); //it would be more correct to report *after* work was done!
                 //OTOH: ThreadInterruption must not happen after last deletion was successful: allow for transactional file model update!
+                warn_static("=> indeed; fix!?")
             };
             static_assert(std::is_const_v<decltype(txtRemovingFile_)>, "callbacks better be thread-safe!");
             auto onBeforeFileDeletion = [&](const std::wstring& displayPath) { notifyDeletion(txtRemovingFile_,   displayPath); };
@@ -754,6 +755,7 @@ void DeletionHandler::removeDirWithCallback(const AbstractPath& folderPath,//thr
             {
                 statReporter.reportStatus(replaceCpy(replaceCpy(statusText, L"%x", L"\n" + fmtPath(displayPathFrom)), L"%y", L"\n" + fmtPath(displayPathTo))); //throw ThreadInterruption
                 statReporter.reportDelta(1, 0); //it would be more correct to report *after* work was done!
+                warn_static("=> indeed; fix!?")
             };
             static_assert(std::is_const_v<decltype(txtMovingFileXtoY_)>, "callbacks better be thread-safe!");
             auto onBeforeFileMove   = [&](const std::wstring& displayPathFrom, const std::wstring& displayPathTo) { notifyMove(txtMovingFileXtoY_,   displayPathFrom, displayPathTo); };
@@ -1056,7 +1058,7 @@ void FolderPairSyncer::runPass(PassNo pass, SyncCtx& syncCtx, BaseFolderPair& ba
     workload.addWorkItems(fps.getFolderLevelWorkItems(pass, baseFolder, workload)); //initial workload: set *before* threads get access!
 
     std::vector<InterruptibleThread> worker;
-    ZEN_ON_SCOPE_EXIT( for (InterruptibleThread& wt : worker) wt.join     (); );
+    ZEN_ON_SCOPE_EXIT( for (InterruptibleThread& wt : worker) wt.join     (); ); //
     ZEN_ON_SCOPE_EXIT( for (InterruptibleThread& wt : worker) wt.interrupt(); ); //interrupt all first, then join
 
     for (size_t threadIdx = 0; threadIdx < threadCount; ++threadIdx)
@@ -1164,10 +1166,10 @@ III) c -> d      caveat: move-sequence needs to be processed in correct order!
 */
 
 template <class List> inline
-bool haveNameClash(const Zstring& shortname, const List& m)
+bool haveNameClash(const Zstring& itemName, const List& m)
 {
     return std::any_of(m.begin(), m.end(),
-    [&](const typename List::value_type& obj) { return equalFilePath(obj.getPairItemName(), shortname); });
+    [&](const typename List::value_type& obj) { return equalNoCase(obj.getItemNameAny(), itemName); }); //equalNoCase: when in doubt => assume name clash!
 }
 
 
@@ -1192,7 +1194,7 @@ void FolderPairSyncer::setup2StepMove(FilePair& sourceFile, //throw FileError, T
                AFS::getDisplayPath(sourceFile.getAbstractPath<side>()),
                AFS::getDisplayPath(sourcePathTmp));
 
-    parallel::renameItem(sourceFile.getAbstractPath<side>(), sourcePathTmp, singleThread_); //throw FileError, (ErrorDifferentVolume)
+    parallel::moveAndRenameItem(sourceFile.getAbstractPath<side>(), sourcePathTmp, singleThread_); //throw FileError, (ErrorDifferentVolume)
 
     //TODO: prepare2StepMove: consider ErrorDifferentVolume! e.g. symlink aliasing!
 
@@ -1226,9 +1228,9 @@ auto FolderPairSyncer::createMoveTargetFolder(FileSystemObject& fsObj) -> CmtfSt
             return cmtfs;
 
         //detect (and try to resolve) file type conflicts: 1. symlinks 2. files
-        const Zstring& shortname = parentFolder->getPairItemName();
-        if (haveNameClash(shortname, parentFolder->parent().refSubLinks()) ||
-            haveNameClash(shortname, parentFolder->parent().refSubFiles()))
+        const Zstring& folderName = parentFolder->getItemNameAny();
+        if (haveNameClash(folderName, parentFolder->parent().refSubLinks()) ||
+            haveNameClash(folderName, parentFolder->parent().refSubFiles()))
             return CmtfStatus::NAME_CLASH;
 
         //-------- create parent folder if needed --------------
@@ -1266,7 +1268,7 @@ auto FolderPairSyncer::createMoveTargetFolder(FileSystemObject& fsObj) -> CmtfSt
                 }
                 else //source deleted meanwhile...
                 {
-                    //attention when fixing statistics due to missing folder: child items may be scheduled for move, so deletion will have move references flip back to copy + delete!
+                    //attention when fixing statistics due to missing folder: child items may be scheduled for move, so deletion will have move-references flip back to copy + delete!
                     const SyncStatistics statsBefore(parentFolder->base()); //=> don't bother considering move operations, just calculate over the whole tree
                     parentFolder->removeObject<sideSrc>(); //DON'T physically delete child objects while we're still evaluating them, e.g. fsObj, and in caller code!!!
                     const SyncStatistics statsAfter(parentFolder->base());
@@ -1339,8 +1341,8 @@ void FolderPairSyncer::resolveMoveConflicts(FilePair& sourceFile, //throw FileEr
 
     auto haveNameClash = [](const FilePair& file)
     {
-        return ::haveNameClash(file.getPairItemName(), file.parent().refSubLinks()) ||
-               ::haveNameClash(file.getPairItemName(), file.parent().refSubFolders());
+        return ::haveNameClash(file.getItemNameAny(), file.parent().refSubLinks()) ||
+               ::haveNameClash(file.getItemNameAny(), file.parent().refSubFolders());
     };
 
     if (sourceWillBeDeleted || haveNameClash(sourceFile))
@@ -1450,7 +1452,7 @@ bool FolderPairSyncer::needZeroPass(const FilePair& file)
 
 //1st, 2nd pass requirements:
 // - avoid disk space shortage: 1. delete files, 2. overwrite big with small files first
-// - support change in type: overwrite file by directory, symlink by file, ect.
+// - support change in type: overwrite file by directory, symlink by file, etc.
 
 inline
 FolderPairSyncer::PassNo FolderPairSyncer::getPass(const FilePair& file)
@@ -1585,7 +1587,6 @@ void FolderPairSyncer::synchronizeFileInt(FilePair& file, SyncOperation syncOp)
                 if (parentFolder->isEmpty<sideTrg>()) //BaseFolderPair OTOH is always non-empty and existing in this context => else: fatal error in zen::synchronize()
                     return; //if parent directory creation failed, there's no reason to show more errors!
 
-            //can't use "getAbstractPath<sideTrg>()" as file name is not available!
             const AbstractPath targetPath = file.getAbstractPath<sideTrg>();
             reportInfo(txtCreatingFile_, AFS::getDisplayPath(targetPath)); //throw ThreadInterruption
 
@@ -1636,7 +1637,7 @@ void FolderPairSyncer::synchronizeFileInt(FilePair& file, SyncOperation syncOp)
                 AsyncItemStatReporter statReporter(1, 0, acb_);
 
                 delHandlerTrg.removeFileWithCallback({ file.getAbstractPath<sideTrg>(), file.getAttributes<sideTrg>() },
-                                                     file.getPairRelativePath(), statReporter, singleThread_); //throw FileError, X
+                                                       file.getRelativePath<sideTrg>(), statReporter, singleThread_); //throw FileError, X
                 file.removeObject<sideTrg>(); //update FilePair
             }
             break;
@@ -1660,7 +1661,7 @@ void FolderPairSyncer::synchronizeFileInt(FilePair& file, SyncOperation syncOp)
 
                 //TODO: synchronizeFileInt: consider ErrorDifferentVolume! e.g. symlink aliasing!
 
-                parallel::renameItem(pathFrom, pathTo, singleThread_); //throw FileError, (ErrorDifferentVolume)
+                parallel::moveAndRenameItem(pathFrom, pathTo, singleThread_); //throw FileError, (ErrorDifferentVolume)
 
                 statReporter.reportDelta(1, 0);
 
@@ -1694,8 +1695,9 @@ void FolderPairSyncer::synchronizeFileInt(FilePair& file, SyncOperation syncOp)
             AsyncItemStatReporter statReporter(1, file.getFileSize<sideSrc>(), acb_);
 
             if (file.isFollowedSymlink<sideTrg>()) //since we follow the link, we need to sync case sensitivity of the link manually!
-                if (file.getItemName<sideTrg>() != file.getItemName<sideSrc>()) //have difference in case?
-                    parallel::renameItem(file.getAbstractPath<sideTrg>(), targetPathLogical, singleThread_); //throw FileError, (ErrorDifferentVolume)
+                if (getUnicodeNormalForm(file.getItemName<sideTrg>()) !=
+                    getUnicodeNormalForm(file.getItemName<sideSrc>())) //have difference in case?
+                    parallel::moveAndRenameItem(file.getAbstractPath<sideTrg>(), targetPathLogical, singleThread_); //throw FileError, (ErrorDifferentVolume)
 
             auto onDeleteTargetFile = [&] //delete target at appropriate time
             {
@@ -1704,7 +1706,7 @@ void FolderPairSyncer::synchronizeFileInt(FilePair& file, SyncOperation syncOp)
                 FileAttributes followedTargetAttr = file.getAttributes<sideTrg>();
                 followedTargetAttr.isFollowedSymlink = false;
 
-                delHandlerTrg.removeFileWithCallback({ targetPathResolvedOld, followedTargetAttr }, file.getPairRelativePath(), statReporter, singleThread_); //throw FileError, X
+                delHandlerTrg.removeFileWithCallback({ targetPathResolvedOld, followedTargetAttr }, file.getRelativePath<sideTrg>(), statReporter, singleThread_); //throw FileError, X
                 //no (logical) item count update desired - but total byte count may change, e.g. move(copy) old file to versioning dir
                 statReporter.reportDelta(-1, 0); //undo item stats reporting within DeletionHandler::removeFileWithCallback()
 
@@ -1742,10 +1744,12 @@ void FolderPairSyncer::synchronizeFileInt(FilePair& file, SyncOperation syncOp)
             {
                 AsyncItemStatReporter statReporter(1, 0, acb_);
 
-                assert(file.getItemName<sideTrg>() != file.getItemName<sideSrc>());
-                if (file.getItemName<sideTrg>() != file.getItemName<sideSrc>()) //have difference in case?
-                    parallel::renameItem(file.getAbstractPath<sideTrg>(), //throw FileError, (ErrorDifferentVolume)
-                                         AFS::appendRelPath(file.parent().getAbstractPath<sideTrg>(), file.getItemName<sideSrc>()), singleThread_);
+                if (getUnicodeNormalForm(file.getItemName<sideTrg>()) !=
+                    getUnicodeNormalForm(file.getItemName<sideSrc>())) //have difference in case?
+                    parallel::moveAndRenameItem(file.getAbstractPath<sideTrg>(), //throw FileError, (ErrorDifferentVolume)
+                                                AFS::appendRelPath(file.parent().getAbstractPath<sideTrg>(), file.getItemName<sideSrc>()), singleThread_);
+                else
+                    assert(false);
 
 #if 0 //changing file time without copying content is not justified after CompareVariant::SIZE finds "equal" files! similar issue with CompareVariant::TIME_SIZE and FileTimeTolerance == -1
                 //Bonus: some devices don't support setting (precise) file times anyway, e.g. FAT or MTP!
@@ -1852,7 +1856,7 @@ void FolderPairSyncer::synchronizeLinkInt(SymlinkPair& symlink, SyncOperation sy
             {
                 AsyncItemStatReporter statReporter(1, 0, acb_);
 
-                delHandlerTrg.removeLinkWithCallback(symlink.getAbstractPath<sideTrg>(), symlink.getPairRelativePath(), statReporter, singleThread_); //throw FileError, X
+                delHandlerTrg.removeLinkWithCallback(symlink.getAbstractPath<sideTrg>(), symlink.getRelativePath<sideTrg>(), statReporter, singleThread_); //throw FileError, X
 
                 symlink.removeObject<sideTrg>(); //update SymlinkPair
             }
@@ -1865,7 +1869,7 @@ void FolderPairSyncer::synchronizeLinkInt(SymlinkPair& symlink, SyncOperation sy
                 AsyncItemStatReporter statReporter(1, 0, acb_);
 
                 //reportStatus(delHandlerTrg.getTxtRemovingSymLink(), AFS::getDisplayPath(symlink.getAbstractPath<sideTrg>()));
-                delHandlerTrg.removeLinkWithCallback(symlink.getAbstractPath<sideTrg>(), symlink.getPairRelativePath(), statReporter, singleThread_); //throw FileError, X
+                delHandlerTrg.removeLinkWithCallback(symlink.getAbstractPath<sideTrg>(), symlink.getRelativePath<sideTrg>(), statReporter, singleThread_); //throw FileError, X
                 statReporter.reportDelta(-1, 0); //undo item stats reporting within DeletionHandler::removeLinkWithCallback()
 
                 //symlink.removeObject<sideTrg>(); -> "symlink, sideTrg" evaluated below!
@@ -1892,9 +1896,12 @@ void FolderPairSyncer::synchronizeLinkInt(SymlinkPair& symlink, SyncOperation sy
             {
                 AsyncItemStatReporter statReporter(1, 0, acb_);
 
-                if (symlink.getItemName<sideTrg>() != symlink.getItemName<sideSrc>()) //have difference in case?
-                    parallel::renameItem(symlink.getAbstractPath<sideTrg>(), //throw FileError, (ErrorDifferentVolume)
-                                         AFS::appendRelPath(symlink.parent().getAbstractPath<sideTrg>(), symlink.getItemName<sideSrc>()), singleThread_);
+                if (getUnicodeNormalForm(symlink.getItemName<sideTrg>()) !=
+                    getUnicodeNormalForm(symlink.getItemName<sideSrc>())) //have difference in case?
+                    parallel::moveAndRenameItem(symlink.getAbstractPath<sideTrg>(), //throw FileError, (ErrorDifferentVolume)
+                                                AFS::appendRelPath(symlink.parent().getAbstractPath<sideTrg>(), symlink.getItemName<sideSrc>()), singleThread_);
+                else
+                    assert(false);
 
                 //if (symlink.getLastWriteTime<sideTrg>() != symlink.getLastWriteTime<sideSrc>())
                 //    //- no need to call sameFileTime() or respect 2 second FAT/FAT32 precision in this comparison
@@ -1984,7 +1991,7 @@ void FolderPairSyncer::synchronizeFolderInt(FolderPair& folder, SyncOperation sy
             }
             else //source deleted meanwhile...
             {
-                //attention when fixing statistics due to missing folder: child items may be scheduled for move, so deletion will have move references flip back to copy + delete!
+                //attention when fixing statistics due to missing folder: child items may be scheduled for move, so deletion will have move-references flip back to copy + delete!
                 const SyncStatistics statsBefore(folder.base()); //=> don't bother considering move operations, just calculate over the whole tree
                 folder.refSubFiles  ().clear(); //
                 folder.refSubLinks  ().clear(); //update FolderPair
@@ -2007,7 +2014,7 @@ void FolderPairSyncer::synchronizeFolderInt(FolderPair& folder, SyncOperation sy
                 const SyncStatistics subStats(folder); //counts sub-objects only!
                 AsyncItemStatReporter statReporter(1 + getCUD(subStats), subStats.getBytesToProcess(), acb_);
 
-                delHandlerTrg.removeDirWithCallback(folder.getAbstractPath<sideTrg>(), folder.getPairRelativePath(), statReporter, singleThread_); //throw FileError, X
+                delHandlerTrg.removeDirWithCallback(folder.getAbstractPath<sideTrg>(), folder.getRelativePath<sideTrg>(), statReporter, singleThread_); //throw FileError, X
 
                 //TODO: implement parallel folder deletion
 
@@ -2026,10 +2033,12 @@ void FolderPairSyncer::synchronizeFolderInt(FolderPair& folder, SyncOperation sy
             {
                 AsyncItemStatReporter statReporter(1, 0, acb_);
 
-                assert(folder.getItemName<sideTrg>() != folder.getItemName<sideSrc>());
-                if (folder.getItemName<sideTrg>() != folder.getItemName<sideSrc>()) //have difference in case?
-                    parallel::renameItem(folder.getAbstractPath<sideTrg>(), //throw FileError, (ErrorDifferentVolume)
-                                         AFS::appendRelPath(folder.parent().getAbstractPath<sideTrg>(), folder.getItemName<sideSrc>()), singleThread_);
+                if (getUnicodeNormalForm(folder.getItemName<sideTrg>()) !=
+                    getUnicodeNormalForm(folder.getItemName<sideSrc>())) //have difference in case?
+                    parallel::moveAndRenameItem(folder.getAbstractPath<sideTrg>(), //throw FileError, (ErrorDifferentVolume)
+                                                AFS::appendRelPath(folder.parent().getAbstractPath<sideTrg>(), folder.getItemName<sideSrc>()), singleThread_);
+                else
+                    assert(false);
                 //copyFileTimes -> useless: modification time changes with each child-object creation/deletion
 
                 statReporter.reportDelta(1, 0);
@@ -2109,7 +2118,7 @@ AFS::FileCopyResult FolderPairSyncer::copyFileWithCallback(const FileDescriptor&
 //###########################################################################################
 
 template <SelectedSide side>
-bool baseFolderDrop(BaseFolderPair& baseFolder, std::chrono::seconds folderAccessTimeout, ProcessCallback& callback)
+bool baseFolderDrop(BaseFolderPair& baseFolder, ProcessCallback& callback)
 {
     const AbstractPath folderPath = baseFolder.getAbstractPath<side>();
 
@@ -2118,7 +2127,7 @@ bool baseFolderDrop(BaseFolderPair& baseFolder, std::chrono::seconds folderAcces
         const std::wstring errMsg = tryReportingError([&]
         {
             const FolderStatus status = getFolderStatusNonBlocking({ folderPath }, {} /*deviceParallelOps*/,
-            folderAccessTimeout, false /*allowUserInteraction*/, callback);
+            false /*allowUserInteraction*/, callback);
 
             static_assert(std::is_same_v<decltype(status.failedChecks.begin()->second), FileError>);
             if (!status.failedChecks.empty())
@@ -2137,7 +2146,7 @@ bool baseFolderDrop(BaseFolderPair& baseFolder, std::chrono::seconds folderAcces
 
 
 template <SelectedSide side> //create base directories first (if not yet existing) -> no symlink or attribute copying!
-bool createBaseFolder(BaseFolderPair& baseFolder, bool copyFilePermissions, std::chrono::seconds folderAccessTimeout, ProcessCallback& callback) //return false if fatal error occurred
+bool createBaseFolder(BaseFolderPair& baseFolder, bool copyFilePermissions, ProcessCallback& callback) //return false if fatal error occurred
 {
     static const SelectedSide sideSrc = OtherSide<side>::value;
     const AbstractPath baseFolderPath = baseFolder.getAbstractPath<side>();
@@ -2151,7 +2160,7 @@ bool createBaseFolder(BaseFolderPair& baseFolder, bool copyFilePermissions, std:
         const std::wstring errMsg = tryReportingError([&]
         {
             const FolderStatus status = getFolderStatusNonBlocking({ baseFolderPath },  {} /*deviceParallelOps*/,
-            folderAccessTimeout, false /*allowUserInteraction*/, callback);
+            false /*allowUserInteraction*/, callback);
 
             static_assert(std::is_same_v<decltype(status.failedChecks.begin()->second), FileError>);
             if (!status.failedChecks.empty())
@@ -2206,7 +2215,6 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
                       bool copyFilePermissions,
                       bool failSafeFileCopy,
                       bool runWithBackgroundPriority,
-                      std::chrono::seconds folderAccessTimeout,
                       const std::vector<FolderPairSyncCfg>& syncConfig,
                       FolderComparison& folderCmp,
                       const std::map<AbstractPath, size_t>& deviceParallelOps,
@@ -2329,8 +2337,8 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
         //check for network drops after comparison
         // - convenience: exit sync right here instead of showing tons of errors during file copy
         // - early failure! there's no point in evaluating subsequent warnings
-        if (baseFolderDrop< LEFT_SIDE>(baseFolder, folderAccessTimeout, callback) ||
-            baseFolderDrop<RIGHT_SIDE>(baseFolder, folderAccessTimeout, callback))
+        if (baseFolderDrop< LEFT_SIDE>(baseFolder, callback) ||
+            baseFolderDrop<RIGHT_SIDE>(baseFolder, callback))
         {
             jobType[folderIndex] = FolderPairJobType::SKIP;
             continue;
@@ -2456,10 +2464,10 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
     {
         std::wstring msg = _("The following folders are significantly different. Please check that the correct folders are selected for synchronization.");
 
-        for (const auto& item : significantDiffPairs)
+        for (const auto& [folderPathL, folderPathR] : significantDiffPairs)
             msg += L"\n\n" +
-                   AFS::getDisplayPath(item.first) + L" <-> " + L"\n" +
-                   AFS::getDisplayPath(item.second);
+                   AFS::getDisplayPath(folderPathL) + L" <-> " + L"\n" +
+                   AFS::getDisplayPath(folderPathR);
 
         callback.reportWarning(msg, warnings.warnSignificantDifference);
     }
@@ -2469,10 +2477,10 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
     {
         std::wstring msg = _("Not enough free disk space available in:");
 
-        for (const auto& item : diskSpaceMissing)
-            msg += L"\n\n" + AFS::getDisplayPath(item.first) + L"\n" +
-                   _("Required:")  + L" " + formatFilesizeShort(item.second.first)  + L"\n" +
-                   _("Available:") + L" " + formatFilesizeShort(item.second.second);
+        for (const auto& [folderPath, space] : diskSpaceMissing)
+            msg += L"\n\n" + AFS::getDisplayPath(folderPath) + L"\n" +
+                   _("Required:")  + L" " + formatFilesizeShort(space.first)  + L"\n" +
+                   _("Available:") + L" " + formatFilesizeShort(space.second);
 
         callback.reportWarning(msg, warnings.warnNotEnoughDiskSpace);
     }
@@ -2480,9 +2488,9 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
     //windows: check if recycle bin really exists; if not, Windows will silently delete, which is wrong
     {
         std::wstring msg;
-        for (const auto& item : recyclerSupported)
-            if (!item.second)
-                msg += L"\n" + AFS::getDisplayPath(item.first);
+        for (const auto& [folderPath, supported] : recyclerSupported)
+            if (!supported)
+                msg += L"\n" + AFS::getDisplayPath(folderPath);
 
         if (!msg.empty())
             callback.reportWarning(_("The recycle bin is not supported by the following folders. Deleted or overwritten files will not be able to be restored:") + L"\n" + msg,
@@ -2524,18 +2532,18 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
         {
             std::map<AbstractPath, std::wstring> uniqueMsgs; //=> at most one msg per base folder (*and* per versioningFolderPath)
 
-            for (const auto& item : verCheckBaseFolderPaths) //may contain duplicate paths, but with *different* hard filter!
-                if (std::optional<PathDependency> pd = getPathDependency(versioningFolderPath, NullFilter(), item.first, *item.second))
+            for (const auto& [folderPath, filter] : verCheckBaseFolderPaths) //may contain duplicate paths, but with *different* hard filter!
+                if (std::optional<PathDependency> pd = getPathDependency(versioningFolderPath, NullFilter(), folderPath, *filter))
                 {
                     std::wstring line = L"\n\n" + _("Versioning folder:") + L" \t" + AFS::getDisplayPath(versioningFolderPath) +
-                                        L"\n"   + _("Base folder:")       + L" \t" + AFS::getDisplayPath(item.first);
-                    if (AFS::equalAbstractPath(pd->basePathParent, item.first) && !pd->relPath.empty())
+                                        L"\n"   + _("Base folder:")       + L" \t" + AFS::getDisplayPath(folderPath);
+                    if (AFS::equalAbstractPath(pd->basePathParent, folderPath) && !pd->relPath.empty())
                         line += L"\n" + _("Exclude:") + L" \t" + utfTo<std::wstring>(FILE_NAME_SEPARATOR + pd->relPath + FILE_NAME_SEPARATOR);
 
-                    uniqueMsgs[item.first] = line;
+                    uniqueMsgs[folderPath] = line;
                 }
-            for (const auto& item : uniqueMsgs)
-                msg += item.second;
+            for (const auto& [folderPath, perFolderMsg] : uniqueMsgs)
+                msg += perFolderMsg;
         }
         if (!msg.empty())
             callback.reportWarning(_("The versioning folder is contained in a base folder.") + L"\n" +
@@ -2568,14 +2576,14 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
             //------------------------------------------------------------------------------------------
 
             //checking a second time: (a long time may have passed since folder comparison!)
-            if (baseFolderDrop< LEFT_SIDE>(baseFolder, folderAccessTimeout, callback) ||
-                baseFolderDrop<RIGHT_SIDE>(baseFolder, folderAccessTimeout, callback))
+            if (baseFolderDrop< LEFT_SIDE>(baseFolder, callback) ||
+                baseFolderDrop<RIGHT_SIDE>(baseFolder, callback))
                 continue;
 
             //create base folders if not yet existing
             if (folderPairStat.createCount() > 0 || folderPairCfg.saveSyncDB) //else: temporary network drop leading to deletions already caught by "sourceFolderMissing" check!
-                if (!createBaseFolder< LEFT_SIDE>(baseFolder, copyFilePermissions, folderAccessTimeout, callback) || //+ detect temporary network drop!!
-                    !createBaseFolder<RIGHT_SIDE>(baseFolder, copyFilePermissions, folderAccessTimeout, callback))   //
+                if (!createBaseFolder< LEFT_SIDE>(baseFolder, copyFilePermissions, callback) || //+ detect temporary network drop!!
+                    !createBaseFolder<RIGHT_SIDE>(baseFolder, copyFilePermissions, callback))   //
                     continue;
 
             //------------------------------------------------------------------------------------------
@@ -2699,7 +2707,7 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
 
         //-----------------------------------------------------------------------------------------------------
 
-        applyVersioningLimit(versionLimitFolders, folderAccessTimeout, deviceParallelOps, callback); //throw X
+        applyVersioningLimit(versionLimitFolders, deviceParallelOps, callback); //throw X
 
         //------------------- show warnings after end of synchronization --------------------------------------
 
diff --git a/FreeFileSync/Source/base/synchronization.h b/FreeFileSync/Source/base/synchronization.h
index 3ac1291e..7bd5db5e 100755
--- a/FreeFileSync/Source/base/synchronization.h
+++ b/FreeFileSync/Source/base/synchronization.h
@@ -92,7 +92,6 @@ void synchronize(const std::chrono::system_clock::time_point& syncStartTime,
                  bool copyFilePermissions,
                  bool failSafeFileCopy,
                  bool runWithBackgroundPriority,
-                 std::chrono::seconds folderAccessTimeout,
                  const std::vector<FolderPairSyncCfg>& syncConfig, //CONTRACT: syncConfig and folderCmp correspond row-wise!
                  FolderComparison& folderCmp,                      //
                  const std::map<AbstractPath, size_t>& deviceParallelOps,
diff --git a/FreeFileSync/Source/base/versioning.cpp b/FreeFileSync/Source/base/versioning.cpp
index c5bc2aa6..64536076 100755
--- a/FreeFileSync/Source/base/versioning.cpp
+++ b/FreeFileSync/Source/base/versioning.cpp
@@ -37,7 +37,7 @@ std::pair<time_t, Zstring> fff::impl::parseVersionedFileName(const Zstring& file
 
     const auto itExt1 = fileName.end() - (2 * ext.length() + 18);
     const auto itTs   = itExt1 + ext.length();
-    if (!strEqual(ext, StringRef<const Zchar>(itExt1, itTs), CmpFilePath()))
+    if (!equalString(ext, StringRef<const Zchar>(itExt1, itTs)))
         return {};
 
     const TimeComp tc = parseTime(Zstr(" %Y-%m-%d %H%M%S"), StringRef<const Zchar>(itTs, itTs + 18)); //returns TimeComp() on error
@@ -102,7 +102,7 @@ template <class Function>
 void moveExistingItemToVersioning(const AbstractPath& sourcePath, const AbstractPath& targetPath, //throw FileError
                                   Function copyNewItemPlain /*throw FileError*/)
 {
-    //start deleting existing target as required by copyFileTransactional()/renameItem():
+    //start deleting existing target as required by copyFileTransactional()/moveAndRenameItem():
     //best amortized performance if "target existing" is the most common case
     std::exception_ptr deletionError;
     try { AFS::removeFilePlain(targetPath); /*throw FileError*/ }
@@ -152,7 +152,7 @@ void moveExistingItemToVersioning(const AbstractPath& sourcePath, const Abstract
 
     try //first try to move directly without copying
     {
-        AFS::renameItem(sourcePath, targetPath); //throw FileError, ErrorDifferentVolume
+        AFS::moveAndRenameItem(sourcePath, targetPath); //throw FileError, ErrorDifferentVolume
         //great, we get away cheaply!
     }
     catch (ErrorDifferentVolume&)
@@ -177,7 +177,7 @@ void moveExistingItemToVersioning(const AbstractPath& sourcePath, const Abstract
 
         try //retry
         {
-            AFS::renameItem(sourcePath, targetPath); //throw FileError, ErrorDifferentVolume
+            AFS::moveAndRenameItem(sourcePath, targetPath); //throw FileError, ErrorDifferentVolume
         }
         catch (ErrorDifferentVolume&)
         {
@@ -283,7 +283,7 @@ void FileVersioner::revisionFolderImpl(const AbstractPath& folderPath, const Zst
 
     const Zstring relPathPf = appendSeparator(relativePath);
 
-    for (const auto& fileInfo : files)
+    for (const AFS::FileInfo& fileInfo : files)
     {
         const FileDescriptor fileDescr{ AFS::appendRelPath(folderPath, fileInfo.itemName),
                                         FileAttributes(fileInfo.modTime, fileInfo.fileSize, fileInfo.fileId, false /*isSymlink*/)};
@@ -291,12 +291,12 @@ void FileVersioner::revisionFolderImpl(const AbstractPath& folderPath, const Zst
         revisionFileImpl(fileDescr, relPathPf + fileInfo.itemName, onBeforeFileMove, notifyUnbufferedIO); //throw FileError
     }
 
-    for (const auto& linkInfo : symlinks)
+    for (const AFS::SymlinkInfo& linkInfo : symlinks)
         revisionSymlinkImpl(AFS::appendRelPath(folderPath, linkInfo.itemName),
                             relPathPf + linkInfo.itemName, onBeforeFileMove); //throw FileError
 
     //move folders recursively
-    for (const auto& folderInfo : folders)
+    for (const AFS::FolderInfo& folderInfo : folders)
         revisionFolderImpl(AFS::appendRelPath(folderPath, folderInfo.itemName), //throw FileError
                            relPathPf + folderInfo.itemName,
                            onBeforeFileMove, onBeforeFolderMove, notifyUnbufferedIO);
@@ -348,23 +348,21 @@ void findFileVersions(VersionInfoMap& versions,
         }
     };
 
-    for (const auto& item : folderCont.files)
-        extractFileVersion(item.first, false /*isSymlink*/);
+    for (const auto& [fileName, attr] : folderCont.files)
+        extractFileVersion(fileName, false /*isSymlink*/);
 
-    for (const auto& item : folderCont.symlinks)
-        extractFileVersion(item.first, true /*isSymlink*/);
+    for (const auto& [linkName, attr] : folderCont.symlinks)
+        extractFileVersion(linkName, true /*isSymlink*/);
 
-    for (const auto& item : folderCont.folders)
+    for (const auto& [folderName, attrAndSub] : folderCont.folders)
     {
-        const Zstring& folderName = item.first;
-
         if (relPathOrigParent.empty() && !versionTimeParent) //VersioningStyle::TIMESTAMP_FOLDER?
         {
             assert(!versionTimeParent);
             const time_t versionTime = fff::impl::parseVersionedFolderName(folderName);
             if (versionTime != 0)
             {
-                findFileVersions(versions, item.second.second,
+                findFileVersions(versions, attrAndSub.second,
                                  AFS::appendRelPath(parentFolderPath, folderName),
                                  Zstring(), //[!] skip time-stamped folder
                                  &versionTime);
@@ -372,7 +370,7 @@ void findFileVersions(VersionInfoMap& versions,
             }
         }
 
-        findFileVersions(versions, item.second.second,
+        findFileVersions(versions, attrAndSub.second,
                          AFS::appendRelPath(parentFolderPath, folderName),
                          AFS::appendPaths(relPathOrigParent, folderName, FILE_NAME_SEPARATOR),
                          versionTimeParent);
@@ -387,8 +385,8 @@ void getFolderItemCount(std::map<AbstractPath, size_t>& folderItemCount, const F
     //theoretically possible that the same folder is found in one case with items, in another case empty (due to an error)
     //e.g. "subfolder" for versioning folders c:\folder and c:\folder\subfolder
 
-    for (const auto& item : folderCont.folders)
-        getFolderItemCount(folderItemCount, item.second.second, AFS::appendRelPath(parentFolderPath, item.first));
+    for (const auto& [folderName, attrAndSub] : folderCont.folders)
+        getFolderItemCount(folderItemCount, attrAndSub.second, AFS::appendRelPath(parentFolderPath, folderName));
 }
 }
 
@@ -413,7 +411,6 @@ bool fff::operator<(const VersioningLimitFolder& lhs, const VersioningLimitFolde
 
 
 void fff::applyVersioningLimit(const std::set<VersioningLimitFolder>& limitFolders,
-                               std::chrono::seconds folderAccessTimeout,
                                const std::map<AbstractPath, size_t>& deviceParallelOps,
                                ProcessCallback& callback /*throw X*/)
 {
@@ -429,7 +426,7 @@ void fff::applyVersioningLimit(const std::set<VersioningLimitFolder>& limitFolde
         tryReportingError([&]
         {
             const FolderStatus status = getFolderStatusNonBlocking(folderPaths, deviceParallelOps, //re-check *all* directories on each try!
-                                                                   folderAccessTimeout, false /*allowUserInteraction*/, callback); //throw X
+                                                                   false /*allowUserInteraction*/, callback); //throw X
 
             foldersToRead.clear();
             for (const AbstractPath& folderPath : status.existing)
@@ -439,12 +436,12 @@ void fff::applyVersioningLimit(const std::set<VersioningLimitFolder>& limitFolde
             {
                 std::wstring msg = _("Cannot find the following folders:") + L"\n";
 
-                for (const auto& fc : status.failedChecks)
-                    msg += L"\n" + AFS::getDisplayPath(fc.first);
+                for (const auto& [folderPath, error] : status.failedChecks)
+                    msg += L"\n" + AFS::getDisplayPath(folderPath);
 
                 msg += L"\n___________________________________________";
-                for (const auto& fc : status.failedChecks)
-                    msg += L"\n\n" + replaceCpy(fc.second.toString(), L"\n\n", L"\n");
+                for (const auto& [folderPath, error] : status.failedChecks)
+                    msg += L"\n\n" + replaceCpy(error.toString(), L"\n\n", L"\n");
 
                 throw FileError(msg);
             }
@@ -484,28 +481,29 @@ void fff::applyVersioningLimit(const std::set<VersioningLimitFolder>& limitFolde
     std::map<AbstractPath, VersionInfoMap> versionDetails; //versioningFolderPath => <version details>
     std::map<AbstractPath, size_t> folderItemCount; //<folder path> => <item count> for determination of empty folders
 
-    for (const auto& item : folderBuf)
+    for (const auto& [folderKey, folderVal] : folderBuf)
     {
-        const AbstractPath versioningFolderPath = item.first.folderPath;
-        const DirectoryValue& dirVal            = item.second;
+        const AbstractPath versioningFolderPath = folderKey.folderPath;
 
         assert(versionDetails.find(versioningFolderPath) == versionDetails.end());
 
         findFileVersions(versionDetails[versioningFolderPath],
-                         dirVal.folderCont,
+                         folderVal.folderCont,
                          versioningFolderPath,
                          Zstring() /*relPathOrigParent*/,
                          nullptr /*versionTimeParent*/);
 
         //determine item count per folder for later detection and removal of empty folders:
-        getFolderItemCount(folderItemCount, dirVal.folderCont, versioningFolderPath);
+        getFolderItemCount(folderItemCount, folderVal.folderCont, versioningFolderPath);
 
         //make sure the versioning folder is never found empty and is not deleted:
         ++folderItemCount[versioningFolderPath];
 
+        warn_static("TODO: unicode normalization, case-sensitivity!")
+
         //similarly, failed folder traversal should not make folders look empty:
-        for (const auto& item2 : dirVal.failedFolderReads) ++folderItemCount[AFS::appendRelPath(versioningFolderPath, item2.first)];
-        for (const auto& item2 : dirVal.failedItemReads  ) ++folderItemCount[AFS::appendRelPath(versioningFolderPath, beforeLast(item2.first, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE))];
+        for (const auto& [relPath, errorMsg] : folderVal.failedFolderReads) ++folderItemCount[AFS::appendRelPath(versioningFolderPath, relPath)];
+        for (const auto& [relPath, errorMsg] : folderVal.failedItemReads  ) ++folderItemCount[AFS::appendRelPath(versioningFolderPath, beforeLast(relPath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE))];
     }
 
     //--------- calculate excess file versions ---------
@@ -524,10 +522,8 @@ void fff::applyVersioningLimit(const std::set<VersioningLimitFolder>& limitFolde
     {
         auto it = versionDetails.find(vlf.versioningFolderPath);
         if (it != versionDetails.end())
-            for (auto& item : it->second)
+            for (auto& [versioningFolderPath, versions] : it->second)
             {
-                std::vector<VersionInfo>& versions = item.second;
-
                 size_t versionsToKeep = versions.size();
                 if (vlf.versionMaxAgeDays > 0)
                 {
@@ -581,12 +577,12 @@ void fff::applyVersioningLimit(const std::set<VersioningLimitFolder>& limitFolde
 
     std::vector<std::pair<AbstractPath, ParallelWorkItem>> parallelWorkload;
 
-    for (const auto& item : folderItemCount)
-        if (item.second == 0)
-            parallelWorkload.emplace_back(item.first, deleteEmptyFolderTask);
+    for (const auto& [folderPath, itemCount] : folderItemCount)
+        if (itemCount == 0)
+            parallelWorkload.emplace_back(folderPath, deleteEmptyFolderTask);
 
-    for (const auto& item : itemsToDelete)
-        parallelWorkload.emplace_back(item.first, [isSymlink = item.second, &textRemoving, &folderItemCountShared, &deleteEmptyFolderTask](ParallelContext& ctx) //throw ThreadInterruption
+    for (const auto& [itemPath, isSymlink] : itemsToDelete)
+        parallelWorkload.emplace_back(itemPath, [isSymlink = isSymlink /*=> clang bug :>*/, &textRemoving, &folderItemCountShared, &deleteEmptyFolderTask](ParallelContext& ctx) //throw ThreadInterruption
     {
         const std::wstring errMsg = tryReportingError([&] //throw ThreadInterruption
         {
diff --git a/FreeFileSync/Source/base/versioning.h b/FreeFileSync/Source/base/versioning.h
index a2743e94..f1cefcc5 100755
--- a/FreeFileSync/Source/base/versioning.h
+++ b/FreeFileSync/Source/base/versioning.h
@@ -47,7 +47,7 @@ public:
             throw std::logic_error("Contract violation! " + std::string(__FILE__) + ":" + numberTo<std::string>(__LINE__));
 
         if (timeStamp_.size() != 17) //formatTime() returns empty string on error; unexpected length: e.g. problem in year 10,000!
-            throw FileError(_("Unable to create time stamp for versioning:") + L" \"" + utfTo<std::wstring>(timeStamp_) + L"\"");
+            throw FileError(_("Unable to create time stamp for versioning:") + L" \"" + utfTo<std::wstring>(timeStamp_) + L'"');
     }
 
     //multi-threaded access: internally synchronized!
@@ -103,7 +103,6 @@ bool operator<(const VersioningLimitFolder& lhs, const VersioningLimitFolder& rh
 
 
 void applyVersioningLimit(const std::set<VersioningLimitFolder>& limitFolders,
-                          std::chrono::seconds folderAccessTimeout,
                           const std::map<AbstractPath, size_t>& deviceParallelOps,
                           ProcessCallback& callback /*throw X*/);
 
diff --git a/FreeFileSync/Source/fs/abstract.cpp b/FreeFileSync/Source/fs/abstract.cpp
index e43de243..33b6ec0e 100755
--- a/FreeFileSync/Source/fs/abstract.cpp
+++ b/FreeFileSync/Source/fs/abstract.cpp
@@ -39,8 +39,7 @@ int AFS::compareAbstractPath(const AbstractPath& lhs, const AbstractPath& rhs)
     if (rv != 0)
         return rv;
 
-    return CmpFilePath()(lhs.afsPath.value.c_str(), lhs.afsPath.value.size(),
-                         rhs.afsPath.value.c_str(), rhs.afsPath.value.size());
+    return compareFilePath(lhs.afsPath.value, rhs.afsPath.value);
 }
 
 
@@ -65,17 +64,17 @@ std::optional<AfsPath> AFS::getParentAfsPath(const AfsPath& afsPath)
 void AFS::traverseFolderRecursive(const AbstractPath& basePath, const AFS::TraverserWorkload& workload, size_t parallelOps)
 {
     TraverserWorkloadImpl wlImpl;
-    for (const auto& item : workload)
+    for (const auto& [relPathComponents, cb] : workload)
     {
         AfsPath afsPath = basePath.afsPath;
-        for (const Zstring& itemName : item.first)
+        for (const Zstring& itemName : relPathComponents)
         {
             assert(!contains(itemName, FILE_NAME_SEPARATOR));
             if (!afsPath.value.empty())
                 afsPath.value += FILE_NAME_SEPARATOR;
             afsPath.value += itemName;
         }
-        wlImpl.emplace_back(afsPath, item.second);
+        wlImpl.emplace_back(afsPath, cb);
     }
     basePath.afs->traverseFolderRecursive(wlImpl, parallelOps); //throw
 }
@@ -156,7 +155,7 @@ AFS::FileCopyResult AFS::copyFileAsStream(const AfsPath& afsPathSource, const St
             Native: no, needed for functional correctness, see file_access.cpp
             MTP:    maybe a minor one (need to determine objectId one more time)
             SFTP:   no, needed for functional correctness (synology server), just as for Native
-            FTP:    maybe a minor one: could set modtime via CURLOPT_POSTQUOTE (but this would internally trigger an extra round-trip anyway!)
+            FTP:    no: could set modtime via CURLOPT_POSTQUOTE (but this would internally trigger an extra round-trip anyway!)
         */
         setModTime(apTarget, attrSourceNew.modTime); //throw FileError, follows symlinks
     }
@@ -210,6 +209,9 @@ AFS::FileCopyResult AFS::copyFileTransactional(const AbstractPath& apSource, con
 
     if (transactionalCopy)
     {
+        warn_static("doesnt make sense for Google Drive")
+
+
         std::optional<AbstractPath> parentPath = AFS::getParentFolderPath(apTarget);
         if (!parentPath)
             throw FileError(replaceCpy(_("Cannot write file %x."), L"%x", fmtPath(AFS::getDisplayPath(apTarget))), L"Path is device root.");
@@ -236,7 +238,7 @@ AFS::FileCopyResult AFS::copyFileTransactional(const AbstractPath& apSource, con
             onDeleteTargetFile(); //throw X
 
         //perf: this call is REALLY expensive on unbuffered volumes! ~40% performance decrease on FAT USB stick!
-        renameItem(apTargetTmp, apTarget); //throw FileError, (ErrorDifferentVolume)
+        moveAndRenameItem(apTargetTmp, apTarget); //throw FileError, (ErrorDifferentVolume)
 
         /*
             CAVEAT on FAT/FAT32: the sequence of deleting the target file and renaming "file.txt.ffs_tmp" to "file.txt" does
diff --git a/FreeFileSync/Source/fs/abstract.h b/FreeFileSync/Source/fs/abstract.h
index 887f6b8f..d5de09c7 100755
--- a/FreeFileSync/Source/fs/abstract.h
+++ b/FreeFileSync/Source/fs/abstract.h
@@ -69,6 +69,11 @@ struct AbstractFileSystem //THREAD-SAFETY: "const" member functions must model t
     static Zstring      getRootRelativePath(const AbstractPath& ap) { return ap.afsPath.value; }
 
     //----------------------------------------------------------------------------------------------------------------
+    static void connectNetworkFolder(const AbstractPath& ap, bool allowUserInteraction) { return ap.afs->connectNetworkFolder(ap.afsPath, allowUserInteraction); } //throw FileError
+
+    static int geAccessTimeout(const AbstractPath& ap) { return ap.afs->getAccessTimeout(); } //returns "0" if no timeout in force
+    //----------------------------------------------------------------------------------------------------------------
+
     enum class ItemType
     {
         FILE,
@@ -115,8 +120,6 @@ struct AbstractFileSystem //THREAD-SAFETY: "const" member functions must model t
     //noexcept; optional return value:
     static zen::ImageHolder getFileIcon      (const AbstractPath& ap, int pixelSize) { return ap.afs->getFileIcon      (ap.afsPath, pixelSize); }
     static zen::ImageHolder getThumbnailImage(const AbstractPath& ap, int pixelSize) { return ap.afs->getThumbnailImage(ap.afsPath, pixelSize); }
-
-    static void connectNetworkFolder(const AbstractPath& ap, bool allowUserInteraction) { return ap.afs->connectNetworkFolder(ap.afsPath, allowUserInteraction); } //throw FileError
     //----------------------------------------------------------------------------------------------------------------
 
     using FileId = zen::Zbase<char>;
@@ -234,7 +237,7 @@ struct AbstractFileSystem //THREAD-SAFETY: "const" member functions must model t
     static bool supportPermissionCopy(const AbstractPath& apSource, const AbstractPath& apTarget); //throw FileError
 
     //target existing: undefined behavior! (fail/overwrite/auto-rename)
-    static void renameItem(const AbstractPath& apSource, const AbstractPath& apTarget); //throw FileError, ErrorDifferentVolume
+    static void moveAndRenameItem(const AbstractPath& apSource, const AbstractPath& apTarget); //throw FileError, ErrorDifferentVolume
 
     //Note: it MAY happen that copyFileTransactional() leaves temp files behind, e.g. temporary network drop.
     // => clean them up at an appropriate time (automatically set sync directions to delete them). They have the following ending:
@@ -363,7 +366,7 @@ private:
     virtual bool supportsPermissions(const AfsPath& afsPath) const = 0; //throw FileError
 
     //target existing: undefined behavior! (fail/overwrite/auto-rename)
-    virtual void renameItemForSameAfsType(const AfsPath& afsPathSource, const AbstractPath& apTarget) const = 0; //throw FileError, ErrorDifferentVolume
+    virtual void moveAndRenameItemForSameAfsType(const AfsPath& afsPathSource, const AbstractPath& apTarget) const = 0; //throw FileError, ErrorDifferentVolume
 
     //symlink handling: follow link!
     //target existing: undefined behavior! (fail/overwrite/auto-rename)
@@ -384,6 +387,8 @@ private:
     virtual zen::ImageHolder getThumbnailImage(const AfsPath& afsPath, int pixelSize) const = 0; //
 
     virtual void connectNetworkFolder(const AfsPath& afsPath, bool allowUserInteraction) const = 0; //throw FileError
+
+    virtual int getAccessTimeout() const = 0; //returns "0" if no timeout in force
     //----------------------------------------------------------------------------------------------------------------
 
     virtual uint64_t getFreeDiskSpace(const AfsPath& afsPath) const = 0; //throw FileError, returns 0 if not available
@@ -508,12 +513,12 @@ bool AbstractFileSystem::supportPermissionCopy(const AbstractPath& apSource, con
 
 
 inline
-void AbstractFileSystem::renameItem(const AbstractPath& apSource, const AbstractPath& apTarget) //throw FileError, ErrorDifferentVolume
+void AbstractFileSystem::moveAndRenameItem(const AbstractPath& apSource, const AbstractPath& apTarget) //throw FileError, ErrorDifferentVolume
 {
     using namespace zen;
 
     if (typeid(*apSource.afs) == typeid(*apTarget.afs))
-        return apSource.afs->renameItemForSameAfsType(apSource.afsPath, apTarget); //throw FileError, ErrorDifferentVolume
+        return apSource.afs->moveAndRenameItemForSameAfsType(apSource.afsPath, apTarget); //throw FileError, ErrorDifferentVolume
 
     throw ErrorDifferentVolume(replaceCpy(replaceCpy(_("Cannot move file %x to %y."),
                                                      L"%x", L"\n" + fmtPath(getDisplayPath(apSource))),
diff --git a/FreeFileSync/Source/fs/concrete_impl.h b/FreeFileSync/Source/fs/concrete_impl.h
index e08d9574..08e075a8 100755
--- a/FreeFileSync/Source/fs/concrete_impl.h
+++ b/FreeFileSync/Source/fs/concrete_impl.h
@@ -144,7 +144,7 @@ class GenericDirTraverser
 public:
     using Function1 = zen::GetFirstOfT<Functions...>;
 
-    GenericDirTraverser(std::vector<Task<TravContext, Function1>>&& initialTasks, size_t parallelOps, const std::string& threadGroupName) :
+    GenericDirTraverser(std::vector<Task<TravContext, Function1>>&& initialTasks /*throw X*/, size_t parallelOps, const std::string& threadGroupName) :
         scheduler_(parallelOps, threadGroupName)
     {
         //set the initial work load
@@ -163,18 +163,18 @@ private:
     GenericDirTraverser& operator=(const GenericDirTraverser&) = delete;
 
     template <class Function>
-    void evalResultList(std::vector<TaskResult<TravContext, Function>>& results) //throw X
+    void evalResultList(std::vector<TaskResult<TravContext, Function>>& results /*throw X*/)
     {
         for (TaskResult<TravContext, Function>& result : results)
             evalResult(result); //throw X
     }
 
     template <class Function>
-    void evalResult(TaskResult<TravContext, Function>& result); //throw X
+    void evalResult(TaskResult<TravContext, Function>& result /*throw X*/);
 
     //specialize!
     template <class Function>
-    void evalResultValue(const typename Function::Result& r, std::shared_ptr<AbstractFileSystem::TraverserCallback>& cb); //throw X
+    void evalResultValue(const typename Function::Result& r, std::shared_ptr<AbstractFileSystem::TraverserCallback>& cb /*throw X*/);
 
     TaskScheduler<TravContext, Functions...> scheduler_;
 };
@@ -182,7 +182,7 @@ private:
 
 template <class... Functions>
 template <class Function>
-void GenericDirTraverser<Functions...>::evalResult(TaskResult<TravContext, Function>& result) //throw X
+void GenericDirTraverser<Functions...>::evalResult(TaskResult<TravContext, Function>& result /*throw X*/)
 {
     auto& cb = result.wi.ctx.cb;
     try
diff --git a/FreeFileSync/Source/fs/native.cpp b/FreeFileSync/Source/fs/native.cpp
index fc260d7f..c924777e 100755
--- a/FreeFileSync/Source/fs/native.cpp
+++ b/FreeFileSync/Source/fs/native.cpp
@@ -96,8 +96,33 @@ std::vector<FsItemRaw> getDirContentFlat(const Zstring& dirPath) //throw FileErr
         if (itemNameRaw[0] == '.' &&
             (itemNameRaw[1] == 0 || (itemNameRaw[1] == '.' && itemNameRaw[2] == 0)))
             continue;
+
+        /*
+            Unicode normalization is file-system-dependent:
+
+                OS                Accepts   Gives back
+               ----------         -------   ----------
+               macOS (HFS+)         all        NFD
+               Linux                all      <input>
+               Windows (NTFS, FAT)  all      <input>
+
+            some file systems return precomposed others decomposed UTF8: http://developer.apple.com/library/mac/#qa/qa1173/_index.html
+                  - OS X edit controls and text fields may return precomposed UTF as directly received by keyboard or decomposed UTF that was copy & pasted in!
+                  - Posix APIs require decomposed form: https://freefilesync.org/forum/viewtopic.php?t=2480
+
+            => General recommendation: always preserve input UNCHANGED (both unicode normalization and case sensitivity)
+            => normalize only when needed during string comparison
+
+            Create sample files on Linux: touch  decomposed-$'\x6f\xcc\x81'.txt
+                                          touch precomposed-$'\xc3\xb3'.txt
+
+            - SMB sharing case-sensitive or NFD file names is fundamentally broken on macOS:
+                => the macOS SMB manager internally buffers file names as case-insensitive and NFC (= just like NTFS on Windows)
+                => test: create SMB share from Linux => *boom* on macOS: "Error Code 2: No such file or directory [lstat]"
+                    or WORSE: folders "test" and "Test" *both* incorrectly return the content of one of the two
+        */
         const Zstring& itemName = itemNameRaw;
-        if (itemName.empty()) //checks result of normalizeUtfForPosix, too!
+        if (itemName.empty())
             throw FileError(replaceCpy(_("Cannot read directory %x."), L"%x", fmtPath(dirPath)), L"readdir: Data corruption; item with empty name.");
 
         const Zstring& itemPath = appendSeparator(dirPath) + itemName;
@@ -126,7 +151,7 @@ ItemDetailsRaw getItemDetails(const Zstring& itemPath) //throw FileError
     else if (S_ISDIR(statData.st_mode)) //a directory
         return { ItemType::FOLDER, statData.st_mtime, 0, extractFileId(statData) };
 
-    else //a file or named pipe, ect. => dont't check using S_ISREG(): see comment in file_traverser.cpp
+    else //a file or named pipe, etc. => dont't check using S_ISREG(): see comment in file_traverser.cpp
         return { ItemType::FILE, statData.st_mtime, makeUnsigned(statData.st_size), extractFileId(statData) };
 }
 
@@ -138,7 +163,7 @@ ItemDetailsRaw getSymlinkTargetDetails(const Zstring& linkPath) //throw FileErro
 
     if (S_ISDIR(statData.st_mode)) //a directory
         return { ItemType::FOLDER, statData.st_mtime, 0, extractFileId(statData) };
-    else //a file or named pipe, ect.
+    else //a file or named pipe, etc.
         return { ItemType::FILE, statData.st_mtime, makeUnsigned(statData.st_size), extractFileId(statData) };
 }
 
@@ -198,13 +223,13 @@ private:
 };
 
 
-void traverseFolderRecursiveNative(const std::vector<std::pair<Zstring, std::shared_ptr<AFS::TraverserCallback>>>& initialTasks, size_t parallelOps) //throw X
+void traverseFolderRecursiveNative(const std::vector<std::pair<Zstring, std::shared_ptr<AFS::TraverserCallback>>>& initialTasks /*throw X*/, size_t parallelOps)
 {
     std::vector<Task<TravContext, GetDirDetails>> genItems;
 
-    for (const auto& item : initialTasks)
-        genItems.push_back({ GetDirDetails(item.first),
-                             TravContext{ Zstring() /*errorItemName*/, 0 /*errorRetryCount*/, item.second /*TraverserCallback*/ }});
+    for (const auto& [folderPath, cb] : initialTasks)
+        genItems.push_back({ GetDirDetails(folderPath),
+                             TravContext{ Zstring() /*errorItemName*/, 0 /*errorRetryCount*/, cb /*TraverserCallback*/ }});
 
     GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>(std::move(genItems), parallelOps, "Native Traverser"); //throw X
 }
@@ -214,7 +239,7 @@ namespace fff //specialization in original namespace needed by GCC 6
 {
 template <>
 template <>
-void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::evalResultValue<GetDirDetails>(const GetDirDetails::Result& r, std::shared_ptr<AFS::TraverserCallback>& cb) //throw X
+void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::evalResultValue<GetDirDetails>(const GetDirDetails::Result& r, std::shared_ptr<AFS::TraverserCallback>& cb /*throw X*/)
 {
     for (const FsItemRaw& rawItem : r)
         scheduler_.run<GetItemDetails>({ GetItemDetails(rawItem), TravContext{ rawItem.itemName, 0 /*errorRetryCount*/, cb }});
@@ -223,7 +248,7 @@ void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::e
 
 template <>
 template <>
-void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::evalResultValue<GetItemDetails>(const GetItemDetails::Result& r, std::shared_ptr<AFS::TraverserCallback>& cb) //throw X
+void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::evalResultValue<GetItemDetails>(const GetItemDetails::Result& r, std::shared_ptr<AFS::TraverserCallback>& cb /*throw X*/)
 {
     switch (r.details.type)
     {
@@ -253,7 +278,7 @@ void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::e
 
 template <>
 template <>
-void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::evalResultValue<GetLinkTargetDetails>(const GetLinkTargetDetails::Result& r, std::shared_ptr<AFS::TraverserCallback>& cb) //throw X
+void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::evalResultValue<GetLinkTargetDetails>(const GetLinkTargetDetails::Result& r, std::shared_ptr<AFS::TraverserCallback>& cb /*throw X*/)
 {
     assert(r.link.type == ItemType::SYMLINK && r.target.type != ItemType::SYMLINK);
 
@@ -264,7 +289,7 @@ void GenericDirTraverser<GetDirDetails, GetItemDetails, GetLinkTargetDetails>::e
         if (std::shared_ptr<AFS::TraverserCallback> cbSub = cb->onFolder({ r.raw.itemName, &linkInfo })) //throw X
             scheduler_.run<GetDirDetails>({ GetDirDetails(r.raw.itemPath), TravContext{ Zstring() /*errorItemName*/, 0 /*errorRetryCount*/, std::move(cbSub) }});
     }
-    else //a file or named pipe, ect.
+    else //a file or named pipe, etc.
         cb->onFile({ r.raw.itemName, r.target.fileSize, r.target.modTime, convertToAbstractFileId(r.target.fileId), &linkInfo }); //throw X
 }
 }
@@ -376,8 +401,7 @@ private:
     {
         const Zstring& rootPathRhs = static_cast<const NativeFileSystem&>(afsRhs).rootPath_;
 
-        return CmpFilePath()(rootPath_  .c_str(), rootPath_  .size(),
-                             rootPathRhs.c_str(), rootPathRhs.size());
+        return compareLocalPath(rootPath_, rootPathRhs);
     }
 
     //----------------------------------------------------------------------------------------------------------------
@@ -481,8 +505,8 @@ private:
         //initComForThread() -> done on traverser worker threads
 
         std::vector<std::pair<Zstring, std::shared_ptr<TraverserCallback>>> initialWorkItems;
-        for (const auto& item : workload)
-            initialWorkItems.emplace_back(getNativePath(item.first), item.second);
+        for (const auto& [folderPath, cb] : workload)
+            initialWorkItems.emplace_back(getNativePath(folderPath), cb);
 
         traverseFolderRecursiveNative(initialWorkItems, parallelOps); //throw X
     }
@@ -540,7 +564,7 @@ private:
     }
 
     //target existing: undefined behavior! (fail/overwrite/auto-rename) => Native will fail and give a clear error message
-    void renameItemForSameAfsType(const AfsPath& afsPathSource, const AbstractPath& apTarget) const override //throw FileError, ErrorDifferentVolume
+    void moveAndRenameItemForSameAfsType(const AfsPath& afsPathSource, const AbstractPath& apTarget) const override //throw FileError, ErrorDifferentVolume
     {
         //perf test: detecting different volumes by path is ~30 times faster than having MoveFileEx fail with ERROR_NOT_SAME_DEVICE (6µs vs 190µs)
         //=> maybe we can even save some actual I/O in some cases?
@@ -588,6 +612,7 @@ private:
 
     }
 
+    int getAccessTimeout() const override { return 0; } //returns "0" if no timeout in force
     //----------------------------------------------------------------------------------------------------------------
 
     uint64_t getFreeDiskSpace(const AfsPath& afsPath) const override //throw FileError, returns 0 if not available
diff --git a/FreeFileSync/Source/ui/batch_status_handler.cpp b/FreeFileSync/Source/ui/batch_status_handler.cpp
index a4e45c50..8b52bacf 100755
--- a/FreeFileSync/Source/ui/batch_status_handler.cpp
+++ b/FreeFileSync/Source/ui/batch_status_handler.cpp
@@ -323,7 +323,8 @@ ProcessCallback::Response BatchStatusHandler::reportError(const std::wstring& ms
     if (retryNumber < automaticRetryCount_)
     {
         errorLog_.logMsg(msg + L"\n-> " + _("Automatic retry"), MSG_TYPE_INFO);
-        delayAndCountDown(_("Automatic retry"), automaticRetryDelay_, [&](const std::wstring& statusMsg) { this->reportStatus(_("Error") + L": " + statusMsg); });
+        delayAndCountDown(_("Automatic retry") + (automaticRetryCount_ <= 1 ? L"" :  L" " + numberTo<std::wstring>(retryNumber + 1) + L"/" + numberTo<std::wstring>(automaticRetryCount_)),
+        automaticRetryDelay_, [&](const std::wstring& statusMsg) { this->reportStatus(_("Error") + L": " + statusMsg); });
         return ProcessCallback::RETRY;
     }
 
diff --git a/FreeFileSync/Source/ui/cfg_grid.cpp b/FreeFileSync/Source/ui/cfg_grid.cpp
index 72acf4a6..db49bee4 100755
--- a/FreeFileSync/Source/ui/cfg_grid.cpp
+++ b/FreeFileSync/Source/ui/cfg_grid.cpp
@@ -32,12 +32,12 @@ std::vector<ConfigFileItem> ConfigView::get() const
 {
     std::map<int, ConfigFileItem, std::greater<>> itemsSorted; //sort by last use; put most recent items *first* (looks better in XML than reverted)
 
-    for (const auto& item : cfgList_)
-        itemsSorted.emplace(item.second.lastUseIndex, item.second.cfgItem);
+    for (const auto& [filePath, details] : cfgList_)
+        itemsSorted.emplace(details.lastUseIndex, details.cfgItem);
 
     std::vector<ConfigFileItem> cfgHistory;
-    for (const auto& item : itemsSorted)
-        cfgHistory.emplace_back(item.second);
+    for (const auto& [lastUseIndex, cfgItem] : itemsSorted)
+        cfgHistory.emplace_back(cfgItem);
 
     return cfgHistory;
 }
@@ -70,8 +70,8 @@ void ConfigView::addCfgFiles(const std::vector<Zstring>& filePaths)
 {
     //determine highest "last use" index number of m_listBoxHistory
     int lastUseIndexMax = 0;
-    for (const auto& item : cfgList_)
-        lastUseIndexMax = std::max(lastUseIndexMax, item.second.lastUseIndex);
+    for (const auto& [filePath, details] : cfgList_)
+        lastUseIndexMax = std::max(lastUseIndexMax, details.lastUseIndex);
 
     for (const Zstring& filePath : filePaths)
     {
@@ -84,14 +84,14 @@ void ConfigView::addCfgFiles(const std::vector<Zstring>& filePaths)
 
             std::tie(detail.name, detail.cfgType, detail.isLastRunCfg) = [&]
             {
-                if (equalFilePath(filePath, lastRunConfigPath_))
+                if (equalLocalPath(filePath, lastRunConfigPath_))
                     return std::make_tuple(utfTo<Zstring>(L"<" + _("Last session") + L">"), Details::CFG_TYPE_GUI, true);
 
                 const Zstring fileName = afterLast(filePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL);
 
-                if (endsWith(fileName, Zstr(".ffs_gui"), CmpFilePath()))
+                if (endsWithAsciiNoCase(fileName, Zstr(".ffs_gui")))
                     return std::make_tuple(beforeLast(fileName, Zstr('.'), IF_MISSING_RETURN_NONE), Details::CFG_TYPE_GUI, false);
-                else if (endsWith(fileName, Zstr(".ffs_batch"), CmpFilePath()))
+                else if (endsWithAsciiNoCase(fileName, Zstr(".ffs_batch")))
                     return std::make_tuple(beforeLast(fileName, Zstr('.'), IF_MISSING_RETURN_NONE), Details::CFG_TYPE_BATCH, false);
                 else
                     return std::make_tuple(fileName, Details::CFG_TYPE_NONE, false);
@@ -110,7 +110,7 @@ void ConfigView::addCfgFiles(const std::vector<Zstring>& filePaths)
 
 void ConfigView::removeItems(const std::vector<Zstring>& filePaths)
 {
-    const std::set<Zstring, LessFilePath> pathsSorted(filePaths.begin(), filePaths.end());
+    const std::set<Zstring, LessLocalPath> pathsSorted(filePaths.begin(), filePaths.end());
 
     erase_if(cfgListView_, [&](auto it) { return pathsSorted.find(it->first) != pathsSorted.end(); });
 
@@ -581,7 +581,7 @@ void cfggrid::addAndSelect(Grid& grid, const std::vector<Zstring>& filePaths, bo
 
     grid.clearSelection(GridEventPolicy::DENY);
 
-    const std::set<Zstring, LessFilePath> pathsSorted(filePaths.begin(), filePaths.end());
+    const std::set<Zstring, LessLocalPath> pathsSorted(filePaths.begin(), filePaths.end());
     std::optional<size_t> selectionTopRow;
 
     for (size_t i = 0; i < grid.getRowCount(); ++i)
diff --git a/FreeFileSync/Source/ui/cfg_grid.h b/FreeFileSync/Source/ui/cfg_grid.h
index 37947867..66cd4dd8 100755
--- a/FreeFileSync/Source/ui/cfg_grid.h
+++ b/FreeFileSync/Source/ui/cfg_grid.h
@@ -134,7 +134,7 @@ private:
 
     const Zstring lastRunConfigPath_ = getLastRunConfigPath(); //let's not use another static...
 
-    using CfgFileList = std::map<Zstring /*file path*/, Details, LessFilePath>;
+    using CfgFileList = std::map<Zstring /*file path*/, Details, LessLocalPath>;
 
     CfgFileList cfgList_;
     std::vector<CfgFileList::iterator> cfgListView_; //sorted view on cfgList_
diff --git a/FreeFileSync/Source/ui/command_box.cpp b/FreeFileSync/Source/ui/command_box.cpp
index 81a0aa6f..9d8c7a9b 100755
--- a/FreeFileSync/Source/ui/command_box.cpp
+++ b/FreeFileSync/Source/ui/command_box.cpp
@@ -22,7 +22,7 @@ inline
 std::wstring getSeparationLine() { return std::wstring(50, EM_DASH); } //no space between dashes!
 
 
-std::vector<std::pair<std::wstring, Zstring>> getDefaultCommands() //(gui name/command) pairs
+std::vector<std::pair<std::wstring, Zstring>> getDefaultCommands() //(description/command) pairs
 {
     return
     {
@@ -63,21 +63,21 @@ CommandBox::CommandBox(wxWindow* parent,
 
 void CommandBox::addItemHistory()
 {
-    const Zstring command = trimCpy(getValue());
+    const Zstring newCommand = trimCpy(getValue());
 
-    if (command == utfTo<Zstring>(getSeparationLine()) || //do not add sep. line
-        command.empty())
+    if (newCommand == utfTo<Zstring>(getSeparationLine()) || //do not add sep. line
+        newCommand.empty())
         return;
 
     //do not add built-in commands to history
-    for (const auto& item : defaultCommands_)
-        if (command == utfTo<Zstring>(item.first) ||
-            equalFilePath(command, item.second))
+    for (const auto& [description, cmd] : defaultCommands_)
+        if (newCommand == utfTo<Zstring>(description) ||
+            equalNoCase(newCommand, cmd))
             return;
 
-    erase_if(history_, [&](const Zstring& item) { return equalFilePath(command, item); });
+    erase_if(history_, [&](const Zstring& item) { return equalNoCase(newCommand, item); });
 
-    history_.insert(history_.begin(), command);
+    history_.insert(history_.begin(), newCommand);
 
     if (history_.size() > historyMax_)
         history_.resize(historyMax_);
@@ -104,8 +104,8 @@ void CommandBox::setValueAndUpdateList(const std::wstring& value)
     std::deque<std::wstring> items;
 
     //1. built in commands
-    for (const auto& item : defaultCommands_)
-        items.push_back(item.first);
+    for (const auto& [description, cmd] : defaultCommands_)
+        items.push_back(description);
 
     //2. history elements
     auto histSorted = history_;
@@ -154,9 +154,9 @@ void CommandBox::OnValidateSelection(wxCommandEvent& event)
     if (value == getSeparationLine())
         return setValueAndUpdateList(std::wstring());
 
-    for (const auto& item : defaultCommands_)
-        if (item.first == value)
-            return setValueAndUpdateList(utfTo<std::wstring>(item.second)); //replace GUI name by actual command string
+    for (const auto& [description, cmd] : defaultCommands_)
+        if (description == value)
+            return setValueAndUpdateList(utfTo<std::wstring>(cmd)); //replace GUI name by actual command string
 }
 
 
diff --git a/FreeFileSync/Source/ui/file_grid.cpp b/FreeFileSync/Source/ui/file_grid.cpp
index 1f634cd4..a1af13a3 100755
--- a/FreeFileSync/Source/ui/file_grid.cpp
+++ b/FreeFileSync/Source/ui/file_grid.cpp
@@ -1084,9 +1084,9 @@ private:
             case ColumnTypeCenter::CHECKBOX:
                 break;
             case ColumnTypeCenter::CMP_CATEGORY:
-                return _("Category") + L" (F10)";
+                return _("Category") + L" (F11)";
             case ColumnTypeCenter::SYNC_ACTION:
-                return _("Action")   + L" (F10)";
+                return _("Action")   + L" (F11)";
         }
         return std::wstring();
     }
@@ -1531,7 +1531,7 @@ private:
             return mainWin.GetVirtualSize().GetWidth() > mainWin.GetClientSize().GetWidth();
             //assuming Grid::updateWindowSizes() does its job well, this should suffice!
             //CAVEAT: if horizontal and vertical scrollbar are circular dependent from each other
-            //(h-scrollbar is shown due to v-scrollbar consuming horizontal width, ect...)
+            //(h-scrollbar is shown due to v-scrollbar consuming horizontal width, etc...)
             //while in fact both are NOT needed, this special case results in a bogus need for scrollbars!
             //see https://sourceforge.net/tracker/?func=detail&aid=3514183&group_id=234430&atid=1093083
             // => since we're outside the Grid abstraction, we should not duplicate code to handle this special case as it seems to be insignificant
@@ -1636,8 +1636,8 @@ private:
 
         //last inserted items are processed first in icon buffer:
         std::vector<AbstractPath> newLoad;
-        for (const auto& item : prefetchLoad)
-            newLoad.push_back(item.second);
+        for (const auto& [priority, filePath] : prefetchLoad)
+            newLoad.push_back(filePath);
 
         provRight_.updateNewAndGetUnbufferedIcons(newLoad);
         provLeft_ .updateNewAndGetUnbufferedIcons(newLoad);
diff --git a/FreeFileSync/Source/ui/file_view.cpp b/FreeFileSync/Source/ui/file_view.cpp
index 1d602540..fdf23760 100755
--- a/FreeFileSync/Source/ui/file_view.cpp
+++ b/FreeFileSync/Source/ui/file_view.cpp
@@ -282,7 +282,7 @@ private:
         Test case: 690.000 item pairs, Windows 7 x64 (C:\ vs I:\)
         ----------------------
         CmpNaturalSort: 850 ms
-        CmpFilePath:    233 ms
+        CmpLocalPath:   233 ms
         CmpAsciiNoCase: 189 ms
         No sorting:      30 ms
     */
@@ -293,7 +293,7 @@ private:
         for (ItemPair& item : itemList)
             output.push_back(&item);
 
-        std::sort(output.begin(), output.end(), [](const ItemPair* lhs, const ItemPair* rhs) { return LessNaturalSort()(lhs->getPairItemName(), rhs->getPairItemName()); });
+        std::sort(output.begin(), output.end(), [](const ItemPair* lhs, const ItemPair* rhs) { return LessNaturalSort()(lhs->getItemNameAny(), rhs->getItemNameAny()); });
         return output;
     }
 #endif
diff --git a/FreeFileSync/Source/ui/folder_history_box.h b/FreeFileSync/Source/ui/folder_history_box.h
index 0252d7cd..bcbe343b 100755
--- a/FreeFileSync/Source/ui/folder_history_box.h
+++ b/FreeFileSync/Source/ui/folder_history_box.h
@@ -41,7 +41,7 @@ public:
         const Zstring nameTmp = zen::trimCpy(folderPathPhrase);
 
         //insert new folder or put it to the front if already existing
-        zen::erase_if(folderPathPhrases_, [&](const Zstring& item) { return equalFilePath(item, nameTmp); });
+        zen::erase_if(folderPathPhrases_, [&](const Zstring& item) { return equalNoCase(item, nameTmp); });
 
         folderPathPhrases_.insert(folderPathPhrases_.begin(), nameTmp);
 
@@ -49,7 +49,7 @@ public:
             folderPathPhrases_.resize(maxSize_);
     }
 
-    void delItem(const Zstring& folderPathPhrase) { zen::erase_if(folderPathPhrases_, [&](const Zstring& item) { return equalFilePath(item, folderPathPhrase); }); }
+    void delItem(const Zstring& folderPathPhrase) { zen::erase_if(folderPathPhrases_, [&](const Zstring& item) { return equalNoCase(item, folderPathPhrase); }); }
 
 private:
     size_t maxSize_ = 0;
diff --git a/FreeFileSync/Source/ui/folder_selector.cpp b/FreeFileSync/Source/ui/folder_selector.cpp
index 0d68ccad..c050994b 100755
--- a/FreeFileSync/Source/ui/folder_selector.cpp
+++ b/FreeFileSync/Source/ui/folder_selector.cpp
@@ -44,7 +44,7 @@ void setFolderPathPhrase(const Zstring& folderPathPhrase, FolderHistoryBox* comb
     if (staticText)
     {
         //change static box label only if there is a real difference to what is shown in wxTextCtrl anyway
-        staticText->SetLabel(equalFilePath(appendSeparator(trimCpy(folderPathPhrase)), appendSeparator(folderPathPhraseFmt)) ?
+        staticText->SetLabel(equalNoCase(appendSeparator(trimCpy(folderPathPhrase)), appendSeparator(folderPathPhraseFmt)) ?
                              wxString(_("Drag && drop")) : utfTo<wxString>(folderPathPhraseFmt));
     }
 }
@@ -230,9 +230,7 @@ void FolderSelector::onSelectAltFolder(wxCommandEvent& event)
 
 Zstring FolderSelector::getPath() const
 {
-    Zstring path = utfTo<Zstring>(folderComboBox_.GetValue());
-
-    return path;
+    return utfTo<Zstring>(folderComboBox_.GetValue());
 }
 
 
diff --git a/FreeFileSync/Source/ui/gui_generated.cpp b/FreeFileSync/Source/ui/gui_generated.cpp
index 00b3ff64..24c86623 100755
--- a/FreeFileSync/Source/ui/gui_generated.cpp
+++ b/FreeFileSync/Source/ui/gui_generated.cpp
@@ -312,7 +312,7 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     bSizer1771 = new wxBoxSizer( wxVERTICAL );
 
     m_bpButtonSwapSides = new wxBitmapButton( m_panelTopCenter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW );
-    m_bpButtonSwapSides->SetToolTip( _("Swap sides") );
+    m_bpButtonSwapSides->SetToolTip( _("dummy") );
 
     bSizer1771->Add( m_bpButtonSwapSides, 0, wxEXPAND, 5 );
 
@@ -859,6 +859,11 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
 
     bSizerViewFilter->Add( 0, 0, 1, wxEXPAND, 5 );
 
+    m_bpButtonViewFilterSave = new wxBitmapButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxDefaultSize, wxBU_AUTODRAW );
+    m_bpButtonViewFilterSave->SetToolTip( _("Save as default") );
+
+    bSizerViewFilter->Add( m_bpButtonViewFilterSave, 0, wxALIGN_CENTER_VERTICAL|wxTOP|wxBOTTOM|wxLEFT, 5 );
+
     m_staticTextSelectView = new wxStaticText( m_panelViewFilter, wxID_ANY, _("Select view:"), wxDefaultPosition, wxDefaultSize, 0 );
     m_staticTextSelectView->Wrap( -1 );
     bSizerViewFilter->Add( m_staticTextSelectView, 0, wxALL|wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
@@ -1169,35 +1174,21 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     m_bpButtonShowLog->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnShowLog ), NULL, this );
     m_bpButtonViewTypeSyncAction->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewType ), NULL, this );
     m_bpButtonShowExcluded->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowExcluded->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
+    m_bpButtonViewFilterSave->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnViewFilterSave ), NULL, this );
     m_bpButtonShowDeleteLeft->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowDeleteLeft->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowUpdateLeft->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowUpdateLeft->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowCreateLeft->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowCreateLeft->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowLeftOnly->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowLeftOnly->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowLeftNewer->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowLeftNewer->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowEqual->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowEqual->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowDoNothing->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowDoNothing->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowDifferent->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowDifferent->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowRightNewer->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowRightNewer->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowRightOnly->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowRightOnly->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowCreateRight->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowCreateRight->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowUpdateRight->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowUpdateRight->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowDeleteRight->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowDeleteRight->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
     m_bpButtonShowConflict->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::OnToggleViewButton ), NULL, this );
-    m_bpButtonShowConflict->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::OnViewButtonRightClick ), NULL, this );
 }
 
 MainDialogGenerated::~MainDialogGenerated()
@@ -2645,23 +2636,54 @@ CloudSetupDlgGenerated::CloudSetupDlgGenerated( wxWindow* parent, wxWindowID id,
     m_staticline581 = new wxStaticLine( m_panel41, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxLI_HORIZONTAL );
     bSizer185->Add( m_staticline581, 0, wxEXPAND, 5 );
 
-    wxBoxSizer* bSizer217;
-    bSizer217 = new wxBoxSizer( wxHORIZONTAL );
+    wxBoxSizer* bSizer269;
+    bSizer269 = new wxBoxSizer( wxVERTICAL );
+
+    wxBoxSizer* bSizer270;
+    bSizer270 = new wxBoxSizer( wxHORIZONTAL );
+
+    m_bitmapServerDir = new wxStaticBitmap( m_panel41, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxDefaultSize, 0 );
+    bSizer270->Add( m_bitmapServerDir, 0, wxALIGN_BOTTOM|wxTOP|wxBOTTOM|wxLEFT, 5 );
 
     m_staticText1232 = new wxStaticText( m_panel41, wxID_ANY, _("Directory on server:"), wxDefaultPosition, wxDefaultSize, 0 );
     m_staticText1232->Wrap( -1 );
-    bSizer217->Add( m_staticText1232, 0, wxALIGN_CENTER_VERTICAL|wxTOP|wxBOTTOM|wxLEFT, 5 );
+    bSizer270->Add( m_staticText1232, 1, wxALL|wxALIGN_BOTTOM, 5 );
+
+    m_staticline72 = new wxStaticLine( m_panel41, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxLI_VERTICAL );
+    bSizer270->Add( m_staticline72, 0, wxEXPAND|wxLEFT, 5 );
+
+    wxBoxSizer* bSizer271;
+    bSizer271 = new wxBoxSizer( wxHORIZONTAL );
+
+    m_staticTextTimeout = new wxStaticText( m_panel41, wxID_ANY, _("Access timeout (in seconds):"), wxDefaultPosition, wxDefaultSize, 0 );
+    m_staticTextTimeout->Wrap( -1 );
+    bSizer271->Add( m_staticTextTimeout, 0, wxALIGN_CENTER_VERTICAL|wxTOP|wxBOTTOM|wxLEFT, 5 );
+
+    m_spinCtrlTimeout = new wxSpinCtrl( m_panel41, wxID_ANY, wxEmptyString, wxDefaultPosition, wxSize( -1, -1 ), wxSP_ARROW_KEYS, 1, 2000000000, 1 );
+    bSizer271->Add( m_spinCtrlTimeout, 0, wxALL|wxALIGN_CENTER_VERTICAL, 5 );
+
+
+    bSizer270->Add( bSizer271, 0, wxALL, 5 );
+
+
+    bSizer269->Add( bSizer270, 0, wxEXPAND|wxLEFT, 5 );
+
+    wxBoxSizer* bSizer217;
+    bSizer217 = new wxBoxSizer( wxHORIZONTAL );
 
     m_textCtrlServerPath = new wxTextCtrl( m_panel41, wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, 0 );
-    bSizer217->Add( m_textCtrlServerPath, 1, wxALIGN_CENTER_VERTICAL|wxTOP|wxBOTTOM|wxLEFT, 5 );
+    bSizer217->Add( m_textCtrlServerPath, 1, wxALIGN_CENTER_VERTICAL|wxBOTTOM|wxLEFT, 5 );
 
     m_buttonSelectFolder = new wxButton( m_panel41, wxID_ANY, _("Browse"), wxDefaultPosition, wxDefaultSize, 0 );
     m_buttonSelectFolder->SetToolTip( _("Select a folder") );
 
-    bSizer217->Add( m_buttonSelectFolder, 0, wxALIGN_CENTER_VERTICAL|wxTOP|wxBOTTOM|wxRIGHT, 5 );
+    bSizer217->Add( m_buttonSelectFolder, 0, wxALIGN_CENTER_VERTICAL|wxBOTTOM|wxRIGHT, 5 );
+
+
+    bSizer269->Add( bSizer217, 0, wxEXPAND|wxBOTTOM|wxRIGHT|wxLEFT, 5 );
 
 
-    bSizer185->Add( bSizer217, 0, wxALL|wxEXPAND, 5 );
+    bSizer185->Add( bSizer269, 0, wxEXPAND, 5 );
 
 
     m_panel41->SetSizer( bSizer185 );
diff --git a/FreeFileSync/Source/ui/gui_generated.h b/FreeFileSync/Source/ui/gui_generated.h
index 757634e8..f0b05c75 100755
--- a/FreeFileSync/Source/ui/gui_generated.h
+++ b/FreeFileSync/Source/ui/gui_generated.h
@@ -173,6 +173,7 @@ protected:
     wxStaticText* m_staticTextViewType;
     zen::ToggleButton* m_bpButtonViewTypeSyncAction;
     zen::ToggleButton* m_bpButtonShowExcluded;
+    wxBitmapButton* m_bpButtonViewFilterSave;
     wxStaticText* m_staticTextSelectView;
     zen::ToggleButton* m_bpButtonShowDeleteLeft;
     zen::ToggleButton* m_bpButtonShowUpdateLeft;
@@ -244,7 +245,7 @@ protected:
     virtual void OnSearchGridEnter( wxCommandEvent& event ) { event.Skip(); }
     virtual void OnToggleViewType( wxCommandEvent& event ) { event.Skip(); }
     virtual void OnToggleViewButton( wxCommandEvent& event ) { event.Skip(); }
-    virtual void OnViewButtonRightClick( wxMouseEvent& event ) { event.Skip(); }
+    virtual void OnViewFilterSave( wxCommandEvent& event ) { event.Skip(); }
 
 
 public:
@@ -578,7 +579,11 @@ protected:
     wxTextCtrl* m_textCtrlPasswordHidden;
     wxCheckBox* m_checkBoxShowPassword;
     wxStaticLine* m_staticline581;
+    wxStaticBitmap* m_bitmapServerDir;
     wxStaticText* m_staticText1232;
+    wxStaticLine* m_staticline72;
+    wxStaticText* m_staticTextTimeout;
+    wxSpinCtrl* m_spinCtrlTimeout;
     wxTextCtrl* m_textCtrlServerPath;
     wxButton* m_buttonSelectFolder;
     wxBoxSizer* bSizer255;
diff --git a/FreeFileSync/Source/ui/gui_status_handler.cpp b/FreeFileSync/Source/ui/gui_status_handler.cpp
index 53391ea3..0a52e18a 100755
--- a/FreeFileSync/Source/ui/gui_status_handler.cpp
+++ b/FreeFileSync/Source/ui/gui_status_handler.cpp
@@ -90,6 +90,7 @@ StatusHandlerTemporaryPanel::StatusHandlerTemporaryPanel(MainDialog& dlg,
 
         statusPanel.Show();
         mainDlg_.auiMgr_.Update();
+        mainDlg_.compareStatus_->getAsWindow()->Refresh(); //macOS: fix background corruption for the statistics boxes (call *after* wxAuiManager::Update()
     }
 
     mainDlg_.Update(); //don't wait until idle event!
@@ -214,7 +215,8 @@ ProcessCallback::Response StatusHandlerTemporaryPanel::reportError(const std::ws
     if (retryNumber < automaticRetryCount_)
     {
         errorLog_.logMsg(msg + L"\n-> " + _("Automatic retry"), MSG_TYPE_INFO);
-        delayAndCountDown(_("Automatic retry"), automaticRetryDelay_, [&](const std::wstring& statusMsg) { this->reportStatus(_("Error") + L": " + statusMsg); });
+        delayAndCountDown(_("Automatic retry") + (automaticRetryCount_ <= 1 ? L"" :  L" " + numberTo<std::wstring>(retryNumber + 1) + L"/" + numberTo<std::wstring>(automaticRetryCount_)),
+        automaticRetryDelay_, [&](const std::wstring& statusMsg) { this->reportStatus(_("Error") + L": " + statusMsg); });
         return ProcessCallback::RETRY;
     }
 
@@ -565,7 +567,8 @@ ProcessCallback::Response StatusHandlerFloatingDialog::reportError(const std::ws
     if (retryNumber < automaticRetryCount_)
     {
         errorLog_.logMsg(msg + L"\n-> " + _("Automatic retry"), MSG_TYPE_INFO);
-        delayAndCountDown(_("Automatic retry"), automaticRetryDelay_, [&](const std::wstring& statusMsg) { this->reportStatus(_("Error") + L": " + statusMsg); });
+        delayAndCountDown(_("Automatic retry") + (automaticRetryCount_ <= 1 ? L"" :  L" " + numberTo<std::wstring>(retryNumber + 1) + L"/" + numberTo<std::wstring>(automaticRetryCount_)),
+        automaticRetryDelay_, [&](const std::wstring& statusMsg) { this->reportStatus(_("Error") + L": " + statusMsg); });
         return ProcessCallback::RETRY;
     }
 
diff --git a/FreeFileSync/Source/ui/gui_status_handler.h b/FreeFileSync/Source/ui/gui_status_handler.h
index 768d4d2e..7ba3878b 100755
--- a/FreeFileSync/Source/ui/gui_status_handler.h
+++ b/FreeFileSync/Source/ui/gui_status_handler.h
@@ -53,7 +53,7 @@ private:
 
 
 //StatusHandlerFloatingDialog(SyncProgressDialog) will internally process Window messages! disable GUI controls to avoid unexpected callbacks!
-class StatusHandlerFloatingDialog : public StatusHandler //throw AbortProcess
+class StatusHandlerFloatingDialog : public StatusHandler
 {
 public:
     StatusHandlerFloatingDialog(wxFrame* parentDlg,
@@ -65,7 +65,7 @@ public:
                                 const Zstring& soundFileSyncComplete,
                                 const Zstring& postSyncCommand,
                                 PostSyncCondition postSyncCondition,
-                                bool& autoCloseDialog);
+                                bool& autoCloseDialog); //noexcept!
     ~StatusHandlerFloatingDialog();
 
     void     initNewPhase    (int itemsTotal, int64_t bytesTotal, Phase phaseID) override; //
diff --git a/FreeFileSync/Source/ui/log_panel.cpp b/FreeFileSync/Source/ui/log_panel.cpp
index 7f84a9ed..fc7810e0 100755
--- a/FreeFileSync/Source/ui/log_panel.cpp
+++ b/FreeFileSync/Source/ui/log_panel.cpp
@@ -81,7 +81,7 @@ public:
         return {};
     }
 
-    void updateView(int includedTypes) //MSG_TYPE_INFO | MSG_TYPE_WARNING, ect. see error_log.h
+    void updateView(int includedTypes) //MSG_TYPE_INFO | MSG_TYPE_WARNING, etc. see error_log.h
     {
         viewRef_.clear();
 
diff --git a/FreeFileSync/Source/ui/main_dlg.cpp b/FreeFileSync/Source/ui/main_dlg.cpp
index 5d608955..1cb67b60 100755
--- a/FreeFileSync/Source/ui/main_dlg.cpp
+++ b/FreeFileSync/Source/ui/main_dlg.cpp
@@ -32,7 +32,7 @@
 #include "small_dlgs.h"
 #include "progress_indicator.h"
 #include "folder_pair.h"
-#include "search.h"
+#include "search_grid.h"
 #include "batch_config.h"
 #include "triple_splitter.h"
 #include "app_icon.h"
@@ -79,8 +79,8 @@ bool acceptDialogFileDrop(const std::vector<Zstring>& shellItemPaths)
     return std::any_of(shellItemPaths.begin(), shellItemPaths.end(), [](const Zstring& shellItemPath)
     {
         const Zstring ext = getFileExtension(shellItemPath);
-        return strEqual(ext, Zstr("ffs_gui"),   CmpFilePath()) ||
-               strEqual(ext, Zstr("ffs_batch"), CmpFilePath());
+        return equalAsciiNoCase(ext, Zstr("ffs_gui")) ||
+               equalAsciiNoCase(ext, Zstr("ffs_batch"));
     });
 }
 }
@@ -403,6 +403,8 @@ MainDialog::MainDialog(const Zstring& globalConfigFilePath,
     m_bpButtonHideSearch ->SetBitmapLabel(getResourceImage(L"close_panel"));
     m_bpButtonShowLog    ->SetBitmapLabel(getResourceImage(L"log_file"));
 
+    m_bpButtonViewFilterSave->SetBitmapLabel(getResourceImage(L"file_save_sicon"));
+
     m_textCtrlSearchTxt->SetMinSize(wxSize(fastFromDIP(220), -1));
 
     initViewFilterButtons();
@@ -563,6 +565,7 @@ MainDialog::MainDialog(const Zstring& globalConfigFilePath,
     m_bpButtonCmpConfig ->SetToolTip(replaceCpy(_("C&omparison settings"),      L"&", L"") + L" (F6)"); //
     m_bpButtonSyncConfig->SetToolTip(replaceCpy(_("S&ynchronization settings"), L"&", L"") + L" (F8)"); //
     m_buttonSync        ->SetToolTip(replaceCpy(_("Start &synchronization"),    L"&", L"") + L" (F9)"); //
+    m_bpButtonSwapSides ->SetToolTip(_("Swap sides") + L" (F10)");
 
     m_bpButtonCmpContext ->SetToolTip(m_bpButtonCmpConfig ->GetToolTipText());
     m_bpButtonSyncContext->SetToolTip(m_bpButtonSyncConfig->GetToolTipText());
@@ -957,8 +960,8 @@ void MainDialog::setGlobalCfgOnInit(const XmlGlobalSettings& globalSettings)
     auiMgr_.LoadPerspective(globalSettings.gui.mainDlg.guiPerspectiveLast);
 
     //restore original captions
-    for (const auto& item : captionNameMap)
-        auiMgr_.GetPane(item.second).Caption(item.first);
+    for (const auto& [caption, name] : captionNameMap)
+        auiMgr_.GetPane(name).Caption(caption);
     //--------------------------------------------------------------------------------
 
     //if MainDialog::onQueryEndSession() is called while comparison is active, this panel is saved and restored as "visible"
@@ -1945,6 +1948,13 @@ void MainDialog::onLocalKeyEvent(wxKeyEvent& event) //process key events without
         //return; //-> swallow event!
 
         case WXK_F10:
+        {
+            wxCommandEvent dummy(wxEVT_COMMAND_BUTTON_CLICKED);
+            m_bpButtonSwapSides->Command(dummy); //simulate click
+        }
+        return; //-> swallow event!
+
+        case WXK_F11:
             setViewTypeSyncAction(!m_bpButtonViewTypeSyncAction->isActive());
             return; //-> swallow event!
 
@@ -2103,13 +2113,13 @@ void MainDialog::onTreeGridContext(GridClickEvent& event)
             const bool isFolder = dynamic_cast<const FolderPair*>(selection[0]) != nullptr;
 
             //by short name
-            Zstring labelShort = Zstring(Zstr("*")) + FILE_NAME_SEPARATOR + selection[0]->getPairItemName();
+            Zstring labelShort = Zstring(Zstr("*")) + FILE_NAME_SEPARATOR + selection[0]->getItemNameAny();
             if (isFolder)
                 labelShort += FILE_NAME_SEPARATOR;
             submenu.addItem(utfTo<wxString>(labelShort), [this, &selection, include] { filterShortname(*selection[0], include); });
 
             //by relative path
-            Zstring labelRel = FILE_NAME_SEPARATOR + selection[0]->getPairRelativePath();
+            Zstring labelRel = FILE_NAME_SEPARATOR + selection[0]->getRelativePathAny();
             if (isFolder)
                 labelRel += FILE_NAME_SEPARATOR;
             submenu.addItem(utfTo<wxString>(labelRel), [this, &selection, include] { filterItems(selection, include); });
@@ -2231,20 +2241,20 @@ void MainDialog::onMainGridContextRim(bool leftSide)
             //by extension
             if (!isFolder)
             {
-                const Zstring extension = getFileExtension(selection[0]->getPairItemName());
+                const Zstring extension = getFileExtension(selection[0]->getItemNameAny());
                 if (!extension.empty())
                     submenu.addItem(L"*." + utfTo<wxString>(extension),
                                     [this, extension, include] { filterExtension(extension, include); });
             }
 
             //by short name
-            Zstring labelShort = Zstring(Zstr("*")) + FILE_NAME_SEPARATOR + selection[0]->getPairItemName();
+            Zstring labelShort = Zstring(Zstr("*")) + FILE_NAME_SEPARATOR + selection[0]->getItemNameAny();
             if (isFolder)
                 labelShort += FILE_NAME_SEPARATOR;
             submenu.addItem(utfTo<wxString>(labelShort), [this, &selection, include] { filterShortname(*selection[0], include); });
 
             //by relative path
-            Zstring labelRel = FILE_NAME_SEPARATOR + selection[0]->getPairRelativePath();
+            Zstring labelRel = FILE_NAME_SEPARATOR + selection[0]->getRelativePathAny();
             if (isFolder)
                 labelRel += FILE_NAME_SEPARATOR;
             submenu.addItem(utfTo<wxString>(labelRel), [this, &selection, include] { filterItems(selection, include); });
@@ -2380,7 +2390,7 @@ void MainDialog::filterExtension(const Zstring& extension, bool include)
 
 void MainDialog::filterShortname(const FileSystemObject& fsObj, bool include)
 {
-    Zstring phrase = Zstring(Zstr("*")) + FILE_NAME_SEPARATOR + fsObj.getPairItemName();
+    Zstring phrase = Zstring(Zstr("*")) + FILE_NAME_SEPARATOR + fsObj.getItemNameAny();
     const bool isFolder = dynamic_cast<const FolderPair*>(&fsObj) != nullptr;
     if (isFolder)
         phrase += FILE_NAME_SEPARATOR;
@@ -2402,7 +2412,7 @@ void MainDialog::filterItems(const std::vector<FileSystemObject*>& selection, bo
                 phrase += Zstr("\n");
 
             //#pragma warning(suppress: 6011) -> fsObj bound in this context!
-            phrase += FILE_NAME_SEPARATOR + fsObj->getPairRelativePath();
+            phrase += FILE_NAME_SEPARATOR + fsObj->getRelativePathAny();
 
             const bool isFolder = dynamic_cast<const FolderPair*>(fsObj) != nullptr;
             if (isFolder)
@@ -2418,8 +2428,8 @@ void MainDialog::onGridLabelContextC(GridLabelClickEvent& event)
     ContextMenu menu;
 
     const bool actionView = m_bpButtonViewTypeSyncAction->isActive();
-    menu.addRadio(_("Category") + (actionView  ? L"\tF10" : L""), [&] { setViewTypeSyncAction(false); }, !actionView);
-    menu.addRadio(_("Action")   + (!actionView ? L"\tF10" : L""), [&] { setViewTypeSyncAction(true ); },  actionView);
+    menu.addRadio(_("Category") + (actionView  ? L"\tF11" : L""), [&] { setViewTypeSyncAction(false); }, !actionView);
+    menu.addRadio(_("Action")   + (!actionView ? L"\tF11" : L""), [&] { setViewTypeSyncAction(true ); },  actionView);
 
     menu.popup(*this);
 }
@@ -2723,7 +2733,7 @@ void MainDialog::cfgHistoryRemoveObsolete(const std::vector<Zstring>& filePaths)
 
 void MainDialog::updateUnsavedCfgStatus()
 {
-    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalFilePath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
+    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalLocalPath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
 
     const bool haveUnsavedCfg = lastSavedCfg_ != getConfig();
 
@@ -2770,7 +2780,7 @@ void MainDialog::updateUnsavedCfgStatus()
 
 void MainDialog::OnConfigSave(wxCommandEvent& event)
 {
-    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalFilePath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
+    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalLocalPath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
 
     //if we work on a single named configuration document: save directly if changed
     //else: always show file dialog
@@ -2824,16 +2834,16 @@ bool MainDialog::trySaveConfig(const Zstring* guiFilename) //return true if save
     }
     else
     {
-        Zstring defaultFilePath = activeConfigFiles_.size() == 1 && !equalFilePath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstr("SyncSettings.ffs_gui");
+        const Zstring defaultFilePath = activeConfigFiles_.size() == 1 && !equalLocalPath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstr("SyncSettings.ffs_gui");
+        auto defaultFolder   = utfTo<wxString>(beforeLast(defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE));
+        auto defaultFileName = utfTo<wxString>(afterLast (defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL));
+
         //attention: activeConfigFiles may be an imported *.ffs_batch file! We don't want to overwrite it with a GUI config!
-        if (endsWith(defaultFilePath, Zstr(".ffs_batch"), CmpFilePath()))
-            defaultFilePath = beforeLast(defaultFilePath, Zstr("."), IF_MISSING_RETURN_NONE) + Zstr(".ffs_gui");
+        defaultFileName = beforeLast(defaultFileName, L'.', IF_MISSING_RETURN_ALL) + L".ffs_gui";
 
         wxFileDialog filePicker(this, //put modal dialog on stack: creating this on freestore leads to memleak!
                                 wxString(),
-                                //OS X really needs dir/file separated like this:
-                                utfTo<wxString>(beforeLast(defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE)), //default dir
-                                utfTo<wxString>(afterLast (defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL)), //default file
+                                defaultFolder, defaultFileName, //OS X really needs dir/file separated like this
                                 wxString(L"FreeFileSync (*.ffs_gui)|*.ffs_gui") + L"|" +_("All files") + L" (*.*)|*",
                                 wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
         if (filePicker.ShowModal() != wxID_OK)
@@ -2863,7 +2873,7 @@ bool MainDialog::trySaveBatchConfig(const Zstring* batchFileToUpdate)
 {
     //essentially behave like trySaveConfig(): the collateral damage of not saving GUI-only settings "m_bpButtonViewTypeSyncAction" is negligible
 
-    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalFilePath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
+    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalLocalPath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
 
     //prepare batch config: reuse existing batch-specific settings from file if available
     BatchExclusiveConfig batchExCfg;
@@ -2907,16 +2917,16 @@ bool MainDialog::trySaveBatchConfig(const Zstring* batchFileToUpdate)
             return false;
         updateUnsavedCfgStatus(); //nothing else to update on GUI!
 
-        Zstring defaultFilePath = !activeCfgFilePath.empty() ? activeCfgFilePath : Zstr("BatchRun.ffs_batch");
+        const Zstring defaultFilePath = !activeCfgFilePath.empty() ? activeCfgFilePath : Zstr("BatchRun.ffs_batch");
+        auto defaultFolder   = utfTo<wxString>(beforeLast(defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE));
+        auto defaultFileName = utfTo<wxString>(afterLast (defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL));
+
         //attention: activeConfigFiles may be a *.ffs_gui file! We don't want to overwrite it with a BATCH config!
-        if (endsWith(defaultFilePath, Zstr(".ffs_gui"), CmpFilePath()))
-            defaultFilePath = beforeLast(defaultFilePath, Zstr("."), IF_MISSING_RETURN_NONE) + Zstr(".ffs_batch");
+        defaultFileName = beforeLast(defaultFileName, L'.', IF_MISSING_RETURN_ALL) + L".ffs_batch";
 
         wxFileDialog filePicker(this, //put modal dialog on stack: creating this on freestore leads to memleak!
                                 wxString(),
-                                //OS X really needs dir/file separated like this:
-                                utfTo<wxString>(beforeLast(defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE)), //default dir
-                                utfTo<wxString>(afterLast (defaultFilePath, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_ALL)), //default file
+                                defaultFolder, defaultFileName, //OS X really needs dir/file separated like this
                                 _("FreeFileSync batch") + L" (*.ffs_batch)|*.ffs_batch" + L"|" +_("All files") + L" (*.*)|*",
                                 wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
         if (filePicker.ShowModal() != wxID_OK)
@@ -2947,7 +2957,7 @@ bool MainDialog::saveOldConfig() //return false on user abort
 {
     if (lastSavedCfg_ != getConfig())
     {
-        const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalFilePath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
+        const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalLocalPath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
 
         //notify user about changed settings
         if (globalCfg_.confirmDlgs.popupOnConfigChange)
@@ -3005,7 +3015,7 @@ bool MainDialog::saveOldConfig() //return false on user abort
 
 void MainDialog::OnConfigLoad(wxCommandEvent& event)
 {
-    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalFilePath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
+    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalLocalPath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
 
     wxFileDialog filePicker(this,
                             wxString(),
@@ -3594,7 +3604,7 @@ void MainDialog::setViewFilterDefault()
 }
 
 
-void MainDialog::OnViewButtonRightClick(wxMouseEvent& event)
+void MainDialog::OnViewFilterSave(wxCommandEvent& event)
 {
     auto setButtonDefault = [](const ToggleButton* tb, bool& defaultValue)
     {
@@ -3690,7 +3700,6 @@ void MainDialog::OnCompare(wxCommandEvent& event)
                              globalCfg_.fileTimeTolerance,
                              true, //allowUserInteraction
                              globalCfg_.runWithBackgroundPriority,
-                             globalCfg_.folderAccessTimeout,
                              globalCfg_.createLockFile,
                              dirLocks,
                              extractCompareCfg(guiCfg.mainCfg),
@@ -3850,7 +3859,7 @@ void MainDialog::OnStartSync(wxCommandEvent& event)
         wxCommandEvent dummy(wxEVT_COMMAND_BUTTON_CLICKED);
         m_buttonCompare->Command(dummy); //simulate click
 
-        if (folderCmp_.empty()) //check if user aborted or error occurred, ect...
+        if (folderCmp_.empty()) //check if user aborted or error occurred, etc...
             return;
     }
 
@@ -3876,7 +3885,7 @@ void MainDialog::OnStartSync(wxCommandEvent& event)
     for (const ConfigFileItem& item : cfggrid::getDataView(*m_gridCfgHistory).get())
         logFilePathsToKeep.insert(item.logFilePath);
 
-    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalFilePath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
+    const Zstring activeCfgFilePath = activeConfigFiles_.size() == 1 && !equalLocalPath(activeConfigFiles_[0], lastRunConfigPath_) ? activeConfigFiles_[0] : Zstring();
     const std::chrono::system_clock::time_point syncStartTime = std::chrono::system_clock::now();
 
     bool exitAfterSync = false;
@@ -3886,7 +3895,7 @@ void MainDialog::OnStartSync(wxCommandEvent& event)
         //run this->enableAllElements() BEFORE "exitAfterSync" buf AFTER StatusHandlerFloatingDialog::reportFinalStatus()
 
         //class handling status updates and error messages
-        StatusHandlerFloatingDialog statusHandler(this, //throw AbortProcess
+        StatusHandlerFloatingDialog statusHandler(this,
                                                   syncStartTime,
                                                   guiCfg.mainCfg.ignoreErrors,
                                                   guiCfg.mainCfg.automaticRetryCount,
@@ -3906,7 +3915,7 @@ void MainDialog::OnStartSync(wxCommandEvent& event)
 
             //wxBusyCursor dummy; -> redundant: progress already shown in progress dialog!
 
-            //GUI mode: place directory locks on directories isolated(!) during both comparison and synchronization
+            //GUI mode: end directory lock lifetime after comparion and start new locking right before sync
             std::unique_ptr<LockHolder> dirLocks;
             if (globalCfg_.createLockFile)
             {
@@ -3931,7 +3940,6 @@ void MainDialog::OnStartSync(wxCommandEvent& event)
                         globalCfg_.copyFilePermissions,
                         globalCfg_.failSafeFileCopy,
                         globalCfg_.runWithBackgroundPriority,
-                        globalCfg_.folderAccessTimeout,
                         extractSyncCfg(guiCfg.mainCfg),
                         folderCmp_,
                         deviceParallelOps,
@@ -4099,7 +4107,9 @@ void MainDialog::showLogPanel(bool show)
         }
         logPane.Hide();
     }
+
     auiMgr_.Update();
+    m_panelLog->Refresh(); //macOS: fix background corruption for the statistics boxes (call *after* wxAuiManager::Update()
 }
 
 
@@ -4329,6 +4339,7 @@ void MainDialog::updateGridViewData()
     m_staticTextViewType        ->Show(anyViewButtonShown);
     m_bpButtonViewTypeSyncAction->Show(anyViewButtonShown);
     m_staticTextSelectView      ->Show(anySelectViewButtonShown);
+    m_bpButtonViewFilterSave    ->Show(anySelectViewButtonShown);
 
     m_panelViewFilter->Layout();
 
@@ -4454,8 +4465,7 @@ void MainDialog::hideFindPanel()
 
 void MainDialog::startFindNext(bool searchAscending) //F3 or ENTER in m_textCtrlSearchTxt
 {
-    Zstring searchString = utfTo<Zstring>(trimCpy(m_textCtrlSearchTxt->GetValue()));
-
+    const std::wstring& searchString = utfTo<std::wstring>(trimCpy(m_textCtrlSearchTxt->GetValue()));
 
     if (searchString.empty())
         showFindPanel();
@@ -4871,7 +4881,7 @@ void MainDialog::OnMenuExportFileList(wxCommandEvent& event)
         std::string&& tmp = utfTo<std::string>(val);
 
         if (contains(tmp, CSV_SEP))
-            return '\"' + tmp + '\"';
+            return '"' + tmp + '"';
         else
             return std::move(tmp);
     };
@@ -5080,7 +5090,7 @@ void MainDialog::setViewTypeSyncAction(bool value)
     //if (m_bpButtonViewTypeSyncAction->isActive() == value) return; support polling -> what about initialization?
 
     m_bpButtonViewTypeSyncAction->setActive(value);
-    m_bpButtonViewTypeSyncAction->SetToolTip((value ? _("Action") : _("Category")) + L" (F10)");
+    m_bpButtonViewTypeSyncAction->SetToolTip((value ? _("Action") : _("Category")) + L" (F11)");
 
     //toggle display of sync preview in middle grid
     filegrid::highlightSyncAction(*m_gridMainC, value);
diff --git a/FreeFileSync/Source/ui/main_dlg.h b/FreeFileSync/Source/ui/main_dlg.h
index 70a5fdb7..dbb0d136 100755
--- a/FreeFileSync/Source/ui/main_dlg.h
+++ b/FreeFileSync/Source/ui/main_dlg.h
@@ -153,7 +153,7 @@ private:
     void OnSyncSettingsContext(wxEvent& event);
     void OnGlobalFilterContext(wxEvent& event);
 
-    void OnViewButtonRightClick(wxMouseEvent& event) override;
+    void OnViewFilterSave(wxCommandEvent& event) override;
 
     void applyCompareConfig(bool setDefaultViewType);
 
diff --git a/FreeFileSync/Source/ui/progress_indicator.cpp b/FreeFileSync/Source/ui/progress_indicator.cpp
index 6737996c..a2cfa0fa 100755
--- a/FreeFileSync/Source/ui/progress_indicator.cpp
+++ b/FreeFileSync/Source/ui/progress_indicator.cpp
@@ -325,7 +325,7 @@ void CompareProgressDialog::Impl::updateProgressGui()
 
     warn_static("harmonize phase handling!")
 
-    //write status information to taskbar, parent title ect.
+    //write status information to taskbar, parent title etc.
     switch (syncStat_->currentPhase())
     {
         case ProcessCallback::PHASE_NONE:
@@ -922,12 +922,13 @@ SyncProgressDialogImpl<TopLevelDialog>::~SyncProgressDialogImpl()
         parentFrame_->Disconnect(wxEVT_CHAR_HOOK, wxKeyEventHandler(SyncProgressDialogImpl::onParentKeyEvent), nullptr, this);
 
         parentFrame_->SetTitle(parentTitleBackup_); //restore title text
-
+        
         //make sure main dialog is shown again if still "minimized to systray"! see SyncProgressDialog::closeDirectly()
         parentFrame_->Show();
         //if (parentFrame_->IsIconized()) //caveat: if window is maximized calling Iconize(false) will erroneously un-maximize!
         //    parentFrame_->Iconize(false);
     }
+    //else: don't call "TransformProcessType": consider "switch to main dialog" option during silent batch run
 
     //our client is NOT expecting a second call via notifyWindowTerminate_()!
 }
@@ -1014,14 +1015,14 @@ template <class TopLevelDialog>
 void SyncProgressDialogImpl<TopLevelDialog>::setExternalStatus(const wxString& status, const wxString& progress) //progress may be empty!
 {
     //sys tray: order "top-down": jobname, status, progress
-    wxString systrayTooltip = jobName_.empty() ? status : L"\"" + jobName_ + L"\"\n" + status;
+    wxString systrayTooltip = jobName_.empty() ? status : L'"' + jobName_ + L"\"\n" + status;
     if (!progress.empty())
         systrayTooltip += L" " + progress;
 
     //window caption/taskbar; inverse order: progress, status, jobname
     wxString title = progress.empty() ? status : progress + SPACED_DASH + status;
     if (!jobName_.empty())
-        title += wxString(SPACED_DASH) + L"\"" + jobName_ + L"\"";
+        title += wxString(SPACED_DASH) + L'"' + jobName_ + L'"';
 
     //systray tooltip, if window is minimized
     if (trayIcon_.get())
diff --git a/FreeFileSync/Source/ui/search_grid.cpp b/FreeFileSync/Source/ui/search_grid.cpp
new file mode 100755
index 00000000..50ee3ab0
--- /dev/null
+++ b/FreeFileSync/Source/ui/search_grid.cpp
@@ -0,0 +1,135 @@
+// *****************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under    *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0          *
+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
+// *****************************************************************************
+
+#include "search_grid.h"
+#include <zen/zstring.h>
+#include <zen/utf.h>
+#include <zen/perf.h>
+
+using namespace zen;
+using namespace fff;
+
+
+namespace
+{
+inline std::wstring getUnicodeNormalFormWide(const std::wstring& str) { return utfTo<std::wstring>(getUnicodeNormalForm(utfTo<Zstring>(str))); }
+inline std::wstring makeUpperCopyWide       (const std::wstring& str) { return utfTo<std::wstring>(makeUpperCopy       (utfTo<Zstring>(str))); }
+
+
+template <bool respectCase>
+class MatchFound
+{
+public:
+    MatchFound(const std::wstring& textToFind) : textToFind_(getUnicodeNormalFormWide(textToFind)) {}
+    bool operator()(const std::wstring& phrase) const
+    {
+        if (isAsciiString(phrase.c_str())) //perf: save Zstring conversion for getUnicodeNormalFormWide() when not needed
+            return contains(phrase, textToFind_);
+        else
+            return contains(getUnicodeNormalFormWide(phrase), textToFind_);
+    }
+
+private:
+    const std::wstring textToFind_;
+};
+
+
+template <>
+class MatchFound<false>
+{
+public:
+    MatchFound(const std::wstring& textToFind) : textToFind_(makeUpperCopyWide(textToFind)) {}
+    bool operator()(std::wstring&& phrase) const
+    {
+        if (isAsciiString(phrase.c_str())) //perf: save Zstring conversion for makeUpperCopyWide() when not needed
+        {
+            for (wchar_t& c : phrase) c = asciiToUpper(c);
+            return contains(phrase, textToFind_);
+        }
+        else
+            return contains(makeUpperCopyWide(phrase), textToFind_); //getUnicodeNormalForm() is implied by makeUpperCopy()
+    }
+
+private:
+    const std::wstring textToFind_;
+};
+
+//###########################################################################################
+
+template <bool respectCase>
+ptrdiff_t findRow(const Grid& grid, //return -1 if no matching row found
+                  const std::wstring& searchString,
+                  bool searchAscending,
+                  size_t rowFirst, //specify area to search:
+                  size_t rowLast)  // [rowFirst, rowLast)
+{
+    if (auto prov = grid.getDataProvider())
+    {
+        std::vector<Grid::ColAttributes> colAttr = grid.getColumnConfig();
+        erase_if(colAttr, [](const Grid::ColAttributes& ca) { return !ca.visible; });
+        if (!colAttr.empty())
+        {
+            const MatchFound<respectCase> matchFound(searchString);
+
+            if (searchAscending)
+            {
+                for (size_t row = rowFirst; row < rowLast; ++row)
+                    for (const Grid::ColAttributes& ca : colAttr)
+                        if (matchFound(prov->getValue(row, ca.type)))
+                            return row;
+            }
+            else
+                for (size_t row = rowLast; row-- > rowFirst;)
+                    for (const Grid::ColAttributes& ca : colAttr)
+                        if (matchFound(prov->getValue(row, ca.type)))
+                            return row;
+        }
+    }
+    return -1;
+}
+}
+
+
+std::pair<const Grid*, ptrdiff_t> fff::findGridMatch(const Grid& grid1, const Grid& grid2, const std::wstring& searchString, bool respectCase, bool searchAscending)
+{
+    //PERF_START
+
+    const size_t rowCount1 = grid1.getRowCount();
+    const size_t rowCount2 = grid2.getRowCount();
+
+    size_t cursorRow1 = grid1.getGridCursor();
+    if (cursorRow1 >= rowCount1)
+        cursorRow1 = 0;
+
+    std::pair<const Grid*, ptrdiff_t> result(nullptr, -1);
+
+    auto finishSearch = [&](const Grid& grid, size_t rowFirst, size_t rowLast)
+    {
+        const ptrdiff_t targetRow = respectCase ?
+                                    findRow<true >(grid, searchString, searchAscending, rowFirst, rowLast) :
+                                    findRow<false>(grid, searchString, searchAscending, rowFirst, rowLast);
+        if (targetRow >= 0)
+        {
+            result = { &grid, targetRow };
+            return true;
+        }
+        return false;
+    };
+
+    if (searchAscending)
+    {
+        if (!finishSearch(grid1, cursorRow1 + 1, rowCount1))
+            if (!finishSearch(grid2, 0, rowCount2))
+                finishSearch(grid1, 0, cursorRow1 + 1);
+    }
+    else
+    {
+        if (!finishSearch(grid1, 0, cursorRow1))
+            if (!finishSearch(grid2, 0, rowCount2))
+                finishSearch(grid1, cursorRow1, rowCount1);
+    }
+    return result;
+}
diff --git a/FreeFileSync/Source/ui/search_grid.h b/FreeFileSync/Source/ui/search_grid.h
new file mode 100755
index 00000000..81560f7c
--- /dev/null
+++ b/FreeFileSync/Source/ui/search_grid.h
@@ -0,0 +1,19 @@
+// *****************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under    *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0          *
+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
+// *****************************************************************************
+
+#ifndef SEARCH_H_423905762345342526587
+#define SEARCH_H_423905762345342526587
+
+#include <wx+/grid.h>
+
+
+namespace fff
+{
+std::pair<const zen::Grid*, ptrdiff_t> findGridMatch(const zen::Grid& grid1, const zen::Grid& grid2, const std::wstring& searchString, bool respectCase, bool searchAscending);
+//returns (grid/row) where the value was found, (nullptr, -1) if not found
+}
+
+#endif //SEARCH_H_423905762345342526587
diff --git a/FreeFileSync/Source/ui/small_dlgs.cpp b/FreeFileSync/Source/ui/small_dlgs.cpp
index 08eefc02..7b71fe1e 100755
--- a/FreeFileSync/Source/ui/small_dlgs.cpp
+++ b/FreeFileSync/Source/ui/small_dlgs.cpp
@@ -31,6 +31,7 @@
 #include "../base/hard_filter.h"
 #include "../base/status_handler.h" //updateUiIsAllowed()
 #include "../base/generate_logfile.h"
+#include "../base/icon_buffer.h"
 #include "../version/version.h"
 
 
diff --git a/FreeFileSync/Source/ui/sorting.h b/FreeFileSync/Source/ui/sorting.h
index 04bdc743..e9432907 100755
--- a/FreeFileSync/Source/ui/sorting.h
+++ b/FreeFileSync/Source/ui/sorting.h
@@ -76,17 +76,16 @@ bool lessRelativeFolder(const FileSystemObject& a, const FileSystemObject& b)
 {
     const bool isDirectoryA = isDirectoryPair(a);
     const Zstring& relFolderA = isDirectoryA ?
-                                a.getPairRelativePath() :
-                                a.parent().getPairRelativePath();
+                                a.getRelativePathAny() :
+                                a.parent().getRelativePathAny();
 
     const bool isDirectoryB = isDirectoryPair(b);
     const Zstring& relFolderB = isDirectoryB ?
-                                b.getPairRelativePath() :
-                                b.parent().getPairRelativePath();
+                                b.getRelativePathAny() :
+                                b.parent().getRelativePathAny();
 
     //compare relative names without filepaths first
-    const int rv = CmpNaturalSort()(relFolderA.c_str(), relFolderA.size(),
-                                    relFolderB.c_str(), relFolderB.size());
+    const int rv = compareNatural(relFolderA, relFolderB);
     if (rv != 0)
         return zen::makeSortDirection(std::less<int>(), std::bool_constant<ascending>())(rv, 0);
 
@@ -96,7 +95,7 @@ bool lessRelativeFolder(const FileSystemObject& a, const FileSystemObject& b)
     else if (isDirectoryA)
         return true;
 
-    return zen::makeSortDirection(LessNaturalSort(), std::bool_constant<ascending>())(a.getPairItemName(), b.getPairItemName());
+    return zen::makeSortDirection(LessNaturalSort(), std::bool_constant<ascending>())(a.getItemNameAny(), b.getItemNameAny());
 }
 
 
diff --git a/FreeFileSync/Source/ui/sync_cfg.cpp b/FreeFileSync/Source/ui/sync_cfg.cpp
index f5bb6399..e3b6a7bc 100755
--- a/FreeFileSync/Source/ui/sync_cfg.cpp
+++ b/FreeFileSync/Source/ui/sync_cfg.cpp
@@ -687,9 +687,8 @@ void ConfigDialog::onFilterKeyEvent(wxKeyEvent& event)
 
 FilterConfig ConfigDialog::getFilterConfig() const
 {
-    Zstring includeFilter = utfTo<Zstring>(m_textCtrlInclude->GetValue());
-    Zstring exludeFilter  = utfTo<Zstring>(m_textCtrlExclude->GetValue());
-
+    const Zstring& includeFilter = utfTo<Zstring>(m_textCtrlInclude->GetValue());
+    const Zstring& exludeFilter  = utfTo<Zstring>(m_textCtrlExclude->GetValue());
 
     return FilterConfig(includeFilter, exludeFilter,
                         m_spinCtrlTimespan->GetValue(),
diff --git a/FreeFileSync/Source/ui/tree_grid.cpp b/FreeFileSync/Source/ui/tree_grid.cpp
index 268cb6e4..bf3833b5 100755
--- a/FreeFileSync/Source/ui/tree_grid.cpp
+++ b/FreeFileSync/Source/ui/tree_grid.cpp
@@ -132,16 +132,16 @@ void calcPercentage(std::vector<std::pair<uint64_t, int*>>& workList)
 
     if (total == 0U) //this case doesn't work with the error minimizing algorithm below
     {
-        for (auto& pair : workList)
-            *pair.second = 0;
+        for (auto& [bytes, percent] : workList)
+            *percent = 0;
         return;
     }
 
     int remainingPercent = 100;
-    for (auto& pair : workList)
+    for (auto& [bytes, percent] : workList)
     {
-        *pair.second = static_cast<int>(pair.first * 100U / total); //round down
-        remainingPercent -= *pair.second;
+        *percent = static_cast<int>(bytes * 100U / total); //round down
+        remainingPercent -= *percent;
     }
     assert(remainingPercent >= 0);
     assert(remainingPercent < static_cast<int>(workList.size()));
@@ -193,7 +193,7 @@ struct TreeView::LessShortName
                 else if (!folderR)
                     return true;
 
-                return makeSortDirection(LessNaturalSort() /*even on Linux*/, std::bool_constant<ascending>())(folderL->getPairItemName(), folderR->getPairItemName());
+                return makeSortDirection(LessNaturalSort(), std::bool_constant<ascending>())(folderL->getItemNameAny(), folderR->getItemNameAny());
             }
 
             case TreeView::TYPE_FILES:
@@ -755,7 +755,7 @@ private:
                     if (const TreeView::RootNode* root = dynamic_cast<const TreeView::RootNode*>(node.get()))
                         return root->displayName;
                     else if (const TreeView::DirNode* dir = dynamic_cast<const TreeView::DirNode*>(node.get()))
-                        return utfTo<std::wstring>(dir->folder.getPairItemName());
+                        return utfTo<std::wstring>(dir->folder.getItemNameAny());
                     else if (dynamic_cast<const TreeView::FilesNode*>(node.get()))
                         return _("Files");
                     break;
diff --git a/FreeFileSync/Source/version/version.h b/FreeFileSync/Source/version/version.h
index 0c47fff0..0a978b6c 100755
--- a/FreeFileSync/Source/version/version.h
+++ b/FreeFileSync/Source/version/version.h
@@ -3,7 +3,7 @@
 
 namespace fff
 {
-const char ffsVersion[] = "10.4"; //internal linkage!
+const char ffsVersion[] = "10.5"; //internal linkage!
 const char FFS_VERSION_SEPARATOR = '.';
 }
 
diff --git a/wx+/async_task.h b/wx+/async_task.h
index d1f30fec..df4c3ec6 100755
--- a/wx+/async_task.h
+++ b/wx+/async_task.h
@@ -95,7 +95,7 @@ public:
                 return false;
             });
 
-            for (auto& task : readyTasks)
+            for (std::unique_ptr<Task>& task : readyTasks)
                 task->evaluateResult();
         }
     }
diff --git a/wx+/choice_enum.h b/wx+/choice_enum.h
index 2c424b9f..f2c93927 100755
--- a/wx+/choice_enum.h
+++ b/wx+/choice_enum.h
@@ -103,11 +103,11 @@ Enum getEnumVal(const EnumDescrList<Enum>& mapping, const wxChoice& ctrl)
 
 template <class Enum> void updateTooltipEnumVal(const EnumDescrList<Enum>& mapping, wxChoice& ctrl)
 {
-    const Enum value = getEnumVal(mapping, ctrl);
+    const Enum currentValue = getEnumVal(mapping, ctrl);
 
-    for (const auto& item : mapping.descrList)
-        if (item.first == value)
-            ctrl.SetToolTip(item.second.second);
+    for (const auto& [enumValue, textAndTooltip] : mapping.descrList)
+        if (currentValue == enumValue)
+            ctrl.SetToolTip(textAndTooltip.second);
 }
 }
 
diff --git a/wx+/context_menu.h b/wx+/context_menu.h
index 7f459aca..d856db03 100755
--- a/wx+/context_menu.h
+++ b/wx+/context_menu.h
@@ -72,8 +72,8 @@ public:
     void popup(wxWindow& wnd, const wxPoint& pos = wxDefaultPosition) //show popup menu + process lambdas
     {
         //eventually all events from submenu items will be received by this menu
-        for (const auto& item : commandList_)
-            menu_->Connect(item.first, wxEVT_COMMAND_MENU_SELECTED, wxCommandEventHandler(ContextMenu::onSelection), new GenericCommand(item.second) /*pass ownership*/, this);
+        for (const auto& [itemId, command] : commandList_)
+            menu_->Connect(itemId, wxEVT_COMMAND_MENU_SELECTED, wxCommandEventHandler(ContextMenu::onSelection), new GenericCommand(command) /*pass ownership*/, this);
 
         wnd.PopupMenu(menu_.get(), pos);
         wxTheApp->ProcessPendingEvents(); //make sure lambdas are evaluated before going out of scope;
diff --git a/wx+/dc.h b/wx+/dc.h
index ff2f81bd..e1d803cb 100755
--- a/wx+/dc.h
+++ b/wx+/dc.h
@@ -8,6 +8,7 @@
 #define DC_H_4987123956832143243214
 
 #include <unordered_map>
+#include <optional>
 #include <zen/basic_math.h>
 #include <wx/dcbuffer.h> //for macro: wxALWAYS_NATIVE_DOUBLE_BUFFER
 #include <wx/dcscreen.h>
diff --git a/wx+/graph.cpp b/wx+/graph.cpp
index 38846523..e00bed86 100755
--- a/wx+/graph.cpp
+++ b/wx+/graph.cpp
@@ -846,8 +846,8 @@ void Graph2D::render(wxDC& dc) const
             }
 
             //5. draw corner texts
-            for (const auto& ct : attr_.cornerTexts)
-                drawCornerText(dc, graphArea, ct.second, ct.first, attr_.backgroundColor);
+            for (const auto& [cornerPos, text] : attr_.cornerTexts)
+                drawCornerText(dc, graphArea, text, cornerPos, attr_.backgroundColor);
         }
     }
 }
diff --git a/wx+/grid.h b/wx+/grid.h
index 732a4fcb..ccf7ad64 100755
--- a/wx+/grid.h
+++ b/wx+/grid.h
@@ -9,9 +9,11 @@
 
 #include <memory>
 #include <numeric>
+#include <optional>
+#include <set>
 #include <vector>
-#include <wx/scrolwin.h>
 #include <zen/basic_math.h>
+#include <wx/scrolwin.h>
 
 
 //a user-friendly, extensible and high-performance grid control
@@ -362,10 +364,18 @@ private:
 template <class ColAttrReal>
 std::vector<ColAttrReal> makeConsistent(const std::vector<ColAttrReal>& attribs, const std::vector<ColAttrReal>& defaults)
 {
-    std::vector<ColAttrReal> output = attribs;
-    //make sure each type is existing!
-    output.insert(output.end(), defaults.begin(), defaults.end());
-    removeDuplicates(output, [](const ColAttrReal& lhs, const ColAttrReal& rhs) { return lhs.type < rhs.type; });
+    using ColTypeReal = decltype(ColAttrReal().type);
+    std::vector<ColAttrReal> output;
+
+    std::set<ColTypeReal> usedTypes; //remove duplicates
+    auto appendUnique = [&](const std::vector<ColAttrReal>& attr)
+    {
+        std::copy_if(attr.begin(), attr.end(), std::back_inserter(output),
+        [&](const ColAttrReal& a) { return usedTypes.insert(a.type).second; });
+    };
+    appendUnique(attribs);
+    appendUnique(defaults); //make sure each type is existing!
+
     return output;
 }
 
diff --git a/wx+/image_resources.cpp b/wx+/image_resources.cpp
index d0449fe5..d09a188b 100755
--- a/wx+/image_resources.cpp
+++ b/wx+/image_resources.cpp
@@ -122,14 +122,12 @@ public:
 
         result_.access([&](std::vector<std::pair<std::wstring, ImageHolder>>& r)
         {
-            for (auto& item : r)
+            for (auto& [imageName, ih] : r)
             {
-                ImageHolder& ih = item.second;
-
                 wxImage img(ih.getWidth(), ih.getHeight(), ih.releaseRgb(), false /*static_data*/); //pass ownership
                 img.SetAlpha(ih.releaseAlpha(), false /*static_data*/);
 
-                output.emplace(item.first, std::move(img));
+                output.emplace(imageName, std::move(img));
             }
         });
         return output;
@@ -171,7 +169,8 @@ class GlobalBitmaps
 public:
     static std::shared_ptr<GlobalBitmaps> instance()
     {
-        static Global<GlobalBitmaps> inst(std::make_unique<GlobalBitmaps>());
+        static FunStatGlobal<GlobalBitmaps> inst;
+        inst.initOnce([] { return std::make_unique<GlobalBitmaps>(); });
         assert(runningMainThread()); //wxWidgets is not thread-safe!
         return inst.get();
     }
@@ -179,7 +178,7 @@ public:
     GlobalBitmaps() {}
     ~GlobalBitmaps() { assert(bitmaps_.empty() && anims_.empty()); } //don't leave wxWidgets objects for static destruction!
 
-    void init(const Zstring& filepath);
+    void init(const Zstring& filePath);
     void cleanup()
     {
         bitmaps_.clear();
@@ -239,6 +238,8 @@ void GlobalBitmaps::init(const Zstring& filePath)
             }
             else if (endsWith(name, L".gif"))
                 loadAnimFromZip(streamIn, anims_[name]);
+            else
+                assert(false);
         }
     }
 }
diff --git a/wx+/image_tools.cpp b/wx+/image_tools.cpp
index 4748a590..b314e801 100755
--- a/wx+/image_tools.cpp
+++ b/wx+/image_tools.cpp
@@ -141,10 +141,10 @@ wxImage zen::createImageFromText(const wxString& text, const wxFont& font, const
 
     int maxWidth   = 0;
     int lineHeight = 0;
-    for (const auto& li : lineInfo)
+    for (const auto& [lineText, lineSize] : lineInfo)
     {
-        maxWidth   = std::max(maxWidth,   li.second.GetWidth());
-        lineHeight = std::max(lineHeight, li.second.GetHeight()); //wxWidgets comment "GetTextExtent will return 0 for empty string"
+        maxWidth   = std::max(maxWidth,   lineSize.GetWidth());
+        lineHeight = std::max(lineHeight, lineSize.GetHeight()); //wxWidgets comment "GetTextExtent will return 0 for empty string"
     }
     if (maxWidth == 0 || lineHeight == 0)
         return wxImage();
@@ -160,19 +160,19 @@ wxImage zen::createImageFromText(const wxString& text, const wxFont& font, const
         dc.SetFont(font);
 
         int posY = 0;
-        for (const auto& li : lineInfo)
+        for (const auto& [lineText, lineSize] : lineInfo)
         {
-            if (!li.first.empty())
+            if (!lineText.empty())
                 switch (textAlign)
                 {
                     case ImageStackAlignment::LEFT:
-                        dc.DrawText(li.first, wxPoint(0, posY));
+                        dc.DrawText(lineText, wxPoint(0, posY));
                         break;
                     case ImageStackAlignment::RIGHT:
-                        dc.DrawText(li.first, wxPoint(maxWidth - li.second.GetWidth(), posY));
+                        dc.DrawText(lineText, wxPoint(maxWidth - lineSize.GetWidth(), posY));
                         break;
                     case ImageStackAlignment::CENTER:
-                        dc.DrawText(li.first, wxPoint((maxWidth - li.second.GetWidth()) / 2, posY));
+                        dc.DrawText(lineText, wxPoint((maxWidth - lineSize.GetWidth()) / 2, posY));
                         break;
                 }
 
diff --git a/wx+/zlib_wrap.cpp b/wx+/zlib_wrap.cpp
index cb6e3083..fbbe2f09 100755
--- a/wx+/zlib_wrap.cpp
+++ b/wx+/zlib_wrap.cpp
@@ -5,9 +5,10 @@
 // *****************************************************************************
 
 #include "zlib_wrap.h"
-//include the SAME zlib version that wxWidgets is linking against!
-    //#include <wx/../../../../../Source/src/zlib/zlib.h> //wxWidgets compiled with: --with-zlib=builtin
-    #include <zlib.h> //use same library as used by Curl (zlib is required for HTTP)
+//Windows:     use the SAME zlib version that wxWidgets is linking against! //C:\Data\Projects\wxWidgets\Source\src\zlib\zlib.h
+//Linux/macOS: use zlib system header for both wxWidgets and Curl (zlib is required for HTTP)
+//             => don't compile wxWidgets with: --with-zlib=builtin
+#include <zlib.h>
 
 using namespace zen;
 
diff --git a/zen/file_access.cpp b/zen/file_access.cpp
index a81fdae0..88b70b14 100755
--- a/zen/file_access.cpp
+++ b/zen/file_access.cpp
@@ -381,7 +381,7 @@ void zen::renameFile(const Zstring& pathSource, const Zstring& pathTarget) //thr
         const Zstring parentPathSrc = beforeLast(pathSource, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE);
         const Zstring parentPathTrg = beforeLast(pathTarget, FILE_NAME_SEPARATOR, IF_MISSING_RETURN_NONE);
         //some (broken) devices may fail to rename case directly:
-        if (equalFilePath(parentPathSrc, parentPathTrg))
+        if (equalLocalPath(parentPathSrc, parentPathTrg))
         {
             if (fileNameSrc == fileNameTrg)
                 return; //non-sensical request
diff --git a/zen/file_error.h b/zen/file_error.h
index 086d0998..101d6543 100755
--- a/zen/file_error.h
+++ b/zen/file_error.h
@@ -45,7 +45,7 @@ DEFINE_NEW_FILE_ERROR(ErrorDifferentVolume);
 
 //----------- facilitate usage of std::wstring for error messages --------------------
 
-inline std::wstring fmtPath(const std::wstring& displayPath) { return L'\"' + displayPath + L'\"'; }
+inline std::wstring fmtPath(const std::wstring& displayPath) { return L'"' + displayPath + L'"'; }
 inline std::wstring fmtPath(const Zstring& displayPath) { return fmtPath(utfTo<std::wstring>(displayPath)); }
 inline std::wstring fmtPath(const wchar_t* displayPath) { return fmtPath(std::wstring(displayPath)); } //resolve overload ambiguity
 }
diff --git a/zen/file_traverser.cpp b/zen/file_traverser.cpp
index e342c8ec..cc6e0c0b 100755
--- a/zen/file_traverser.cpp
+++ b/zen/file_traverser.cpp
@@ -78,7 +78,7 @@ void zen::traverseFolder(const Zstring& dirPath,
                 if (onFolder)
                     onFolder({ itemName, itemPath });
             }
-            else //a file or named pipe, ect.
+            else //a file or named pipe, etc.
             {
                 if (onFile)
                     onFile({ itemName, itemPath, makeUnsigned(statData.st_size), statData.st_mtime });
diff --git a/zen/globals.h b/zen/globals.h
index 10975414..024147fa 100755
--- a/zen/globals.h
+++ b/zen/globals.h
@@ -14,14 +14,22 @@
 
 namespace zen
 {
-//solve static destruction order fiasco by providing shared ownership and serialized access to global variables
+/*
+Solve static destruction order fiasco by providing shared ownership and serialized access to global variables
+
+=>there may be accesses to "Global<T>::get()" during process shutdown e.g. _("") used by message in debug_minidump.cpp or by some detached thread assembling an error message!
+=> use trivially-destructible POD only!!!
+
+ATTENTION: function-static globals have the compiler generate "magic statics" == compiler-genenerated locking code which will crash or leak memory when accessed after global is "dead"
+           => "solved" by FunStatGlobal, but we can't have "too many" of these...
+*/
 template <class T>
-class Global
+class Global //don't use for function-scope statics!
 {
 public:
     Global()
     {
-        static_assert(std::is_trivially_destructible_v<Pod>, "this memory needs to live forever");
+        static_assert(std::is_trivially_constructible_v<Pod>&& std::is_trivially_destructible_v<Pod>, "this memory needs to live forever");
         assert(!pod_.inst && !pod_.spinLock); //we depend on static zero-initialization!
     }
 
@@ -52,16 +60,131 @@ public:
     }
 
 private:
-    //avoid static destruction order fiasco: there may be accesses to "Global<T>::get()" during process shutdown
-    //e.g. _("") used by message in debug_minidump.cpp or by some detached thread assembling an error message!
-    //=> use trivially-destructible POD only!!!
     struct Pod
     {
+        std::atomic<bool> spinLock; // { false }; rely entirely on static zero-initialization! => avoid potential contention with worker thread during Global<> construction!
+        //serialize access; can't use std::mutex: has non-trival destructor
         std::shared_ptr<T>* inst;   // = nullptr;
+    } pod_;
+};
+
+//===================================================================================================================
+//===================================================================================================================
+
+struct CleanUpEntry
+{
+    using CleanUpFunction = void (*)(void* callbackData);
+    CleanUpFunction cleanUpFun;
+    void*           callbackData;
+    CleanUpEntry*   prev;
+};
+void registerGlobalForDestruction(CleanUpEntry& entry);
+
+
+template <class T>
+class FunStatGlobal
+{
+public:
+    //No FunStatGlobal() or ~FunStatGlobal()!
+
+    std::shared_ptr<T> get()
+    {
+        static_assert(std::is_trivially_constructible_v<FunStatGlobal>&&
+                      std::is_trivially_destructible_v<FunStatGlobal>, "this class must not generate code for magic statics!");
+
+        while (pod_.spinLock.exchange(true)) ;
+        ZEN_ON_SCOPE_EXIT(pod_.spinLock = false);
+        if (pod_.inst)
+            return *pod_.inst;
+        return nullptr;
+    }
+
+    void set(std::unique_ptr<T>&& newInst)
+    {
+        std::shared_ptr<T>* tmpInst = nullptr;
+        if (newInst)
+            tmpInst = new std::shared_ptr<T>(std::move(newInst));
+        {
+            while (pod_.spinLock.exchange(true)) ;
+            ZEN_ON_SCOPE_EXIT(pod_.spinLock = false);
+
+            std::swap(pod_.inst, tmpInst);
+            registerDestruction();
+        }
+        delete tmpInst;
+    }
+
+    void initOnce(std::unique_ptr<T> (*getInitialValue)())
+    {
+        while (pod_.spinLock.exchange(true)) ;
+        ZEN_ON_SCOPE_EXIT(pod_.spinLock = false);
+
+        if (!pod_.cleanUpEntry.cleanUpFun)
+        {
+            assert(!pod_.inst);
+            if (std::unique_ptr<T> newInst = (*getInitialValue)())
+                pod_.inst = new std::shared_ptr<T>(std::move(newInst));
+            registerDestruction();
+        }
+    }
+
+private:
+    //call while holding pod_.spinLock
+    void registerDestruction()
+    {
+        assert(pod_.spinLock);
+
+        if (!pod_.cleanUpEntry.cleanUpFun)
+        {
+            pod_.cleanUpEntry.callbackData = this;
+            pod_.cleanUpEntry.cleanUpFun = [](void* callbackData)
+            {
+                auto thisPtr = static_cast<FunStatGlobal*>(callbackData);
+                thisPtr->set(nullptr);
+            };
+
+            registerGlobalForDestruction(pod_.cleanUpEntry);
+        }
+    }
+
+    struct Pod
+    {
         std::atomic<bool> spinLock; // { false }; rely entirely on static zero-initialization! => avoid potential contention with worker thread during Global<> construction!
         //serialize access; can't use std::mutex: has non-trival destructor
+        std::shared_ptr<T>* inst;   // = nullptr;
+        CleanUpEntry cleanUpEntry;
     } pod_;
 };
+
+
+inline
+void registerGlobalForDestruction(CleanUpEntry& entry)
+{
+    static struct
+    {
+        std::atomic<bool> spinLock;
+        CleanUpEntry*     head;
+    } cleanUpList;
+
+    static_assert(std::is_trivially_constructible_v<decltype(cleanUpList)>&&
+                  std::is_trivially_destructible_v<decltype(cleanUpList)>, "we must not generate code for magic statics!");
+
+    while (cleanUpList.spinLock.exchange(true)) ;
+    ZEN_ON_SCOPE_EXIT(cleanUpList.spinLock = false);
+
+    std::atexit([]
+    {
+        while (cleanUpList.spinLock.exchange(true)) ;
+        ZEN_ON_SCOPE_EXIT(cleanUpList.spinLock = false);
+
+        (*cleanUpList.head->cleanUpFun)(cleanUpList.head->callbackData);
+        cleanUpList.head = cleanUpList.head->prev; //nicely clean up in reverse order of construction
+    });
+
+    entry.prev = cleanUpList.head;
+    cleanUpList.head = &entry;
+
+}
 }
 
 #endif //GLOBALS_H_8013740213748021573485
diff --git a/zen/guid.h b/zen/guid.h
index 89e800b5..a26688f8 100755
--- a/zen/guid.h
+++ b/zen/guid.h
@@ -9,6 +9,7 @@
 
     #include <fcntl.h> //open
     #include <unistd.h> //close
+    #include <zen/sys_error.h>
     //#include <uuid/uuid.h> -> uuid_generate(), uuid_unparse(); avoid additional dependency for "sudo apt-get install uuid-dev"
 
 
diff --git a/zen/http.cpp b/zen/http.cpp
index d06d3309..1f89bf20 100755
--- a/zen/http.cpp
+++ b/zen/http.cpp
@@ -26,9 +26,9 @@ public:
 
         const bool useTls = [&]
         {
-            if (startsWith(url, Zstr("http://"), CmpAsciiNoCase()))
+            if (startsWithAsciiNoCase(url, Zstr("http://")))
                 return false;
-            if (startsWith(url, Zstr("https://"), CmpAsciiNoCase()))
+            if (startsWithAsciiNoCase(url, Zstr("https://")))
                 return true;
             throw SysError(L"URL uses unexpected protocol.");
         }();
@@ -57,35 +57,16 @@ public:
 
         //https://www.w3.org/Protocols/HTTP/1.0/spec.html#Request-Line
         std::string msg = (postParams ? "POST " : "GET ") + utfTo<std::string>(page) + " HTTP/1.0\r\n";
-        for (const auto& item : headers)
-            msg += item.first + ": " + item.second + "\r\n";
+        for (const auto& [name, value] : headers)
+            msg += name + ": " + value + "\r\n";
         msg += "\r\n";
         msg += postBuf;
 
         //send request
         for (size_t bytesToSend = msg.size(); bytesToSend > 0;)
-        {
-            int bytesSent = 0;
-            for (;;)
-            {
-                bytesSent = ::send(socket_->get(),                //_In_       SOCKET s,
-                                   &*(msg.end() - bytesToSend),   //_In_ const char   *buf,
-                                   static_cast<int>(bytesToSend), //_In_       int    len,
-                                   0);                            //_In_       int    flags
-                if (bytesSent >= 0 || errno != EINTR)
-                    break;
-            }
-            if (bytesSent < 0)
-                THROW_LAST_SYS_ERROR_WSA(L"send");
-            if (bytesSent > static_cast<int>(bytesToSend))
-                throw SysError(L"send: buffer overflow.");
-            if (bytesSent == 0)
-                throw SysError(L"send: zero bytes processed");
-
-            bytesToSend -= bytesSent;
-        }
-        if (::shutdown(socket_->get(), SHUT_WR) != 0)
-            THROW_LAST_SYS_ERROR_WSA(L"shutdown");
+            bytesToSend -= tryWriteSocket(socket_->get(), &*(msg.end() - bytesToSend), bytesToSend); //throw SysError
+
+        shutdownSocketSend(socket_->get()); //throw SysError
 
         //receive response:
         std::string headBuf;
@@ -116,7 +97,7 @@ public:
 
         const std::vector<std::string> statusItems = split(statusBuf, ' ', SplitType::ALLOW_EMPTY); //HTTP-Version SP Status-Code SP Reason-Phrase CRLF
         if (statusItems.size() < 2 || !startsWith(statusItems[0], "HTTP/"))
-            throw SysError(L"Invalid HTTP response: \"" + utfTo<std::wstring>(statusBuf) + L"\"");
+            throw SysError(L"Invalid HTTP response: \"" + utfTo<std::wstring>(statusBuf) + L'"');
 
         statusCode_ = stringTo<int>(statusItems[1]);
 
@@ -175,8 +156,6 @@ public:
 private:
     size_t tryRead(void* buffer, size_t bytesToRead) //throw SysError; may return short, only 0 means EOF!
     {
-        if (bytesToRead == 0) //"read() with a count of 0 returns zero" => indistinguishable from end of file! => check!
-            throw std::logic_error("Contract violation! " + std::string(__FILE__) + ":" + numberTo<std::string>(__LINE__));
         assert(bytesToRead <= getBlockSize()); //block size might be 1000 while reading HTTP header
 
         if (contentRemaining_ >= 0)
@@ -185,21 +164,7 @@ private:
                 return 0;
             bytesToRead = static_cast<size_t>(std::min(static_cast<int64_t>(bytesToRead), contentRemaining_)); //[!] contentRemaining_ > 4 GB possible!
         }
-        int bytesReceived = 0;
-        for (;;)
-        {
-            bytesReceived = ::recv(socket_->get(),                //_In_  SOCKET s,
-                                   static_cast<char*>(buffer),    //_Out_ char   *buf,
-                                   static_cast<int>(bytesToRead), //_In_  int    len,
-                                   0);                            //_In_  int    flags
-            if (bytesReceived >= 0 || errno != EINTR)
-                break;
-        }
-        if (bytesReceived < 0)
-            THROW_LAST_SYS_ERROR_WSA(L"recv");
-        if (static_cast<size_t>(bytesReceived) > bytesToRead) //better safe than sorry
-            throw SysError(L"HttpInputStream::tryRead: buffer overflow.");
-
+        const size_t bytesReceived = tryReadSocket(socket_->get(), buffer, bytesToRead); //throw SysError; may return short, only 0 means EOF!
         if (contentRemaining_ >= 0)
             contentRemaining_ -= bytesReceived;
 
@@ -325,8 +290,8 @@ std::string urldecode(const std::string& str)
 std::string zen::xWwwFormUrlEncode(const std::vector<std::pair<std::string, std::string>>& paramPairs)
 {
     std::string output;
-    for (const auto& pair : paramPairs)
-        output += urlencode(pair.first) + '=' + urlencode(pair.second) + '&';
+    for (const auto& [name, value] : paramPairs)
+        output += urlencode(name) + '=' + urlencode(value) + '&';
     //encode both key and value: https://www.w3.org/TR/html401/interact/forms.html#h-17.13.4.1
     if (!output.empty())
         output.pop_back();
diff --git a/zen/i18n.h b/zen/i18n.h
index 45762861..2ecee45a 100755
--- a/zen/i18n.h
+++ b/zen/i18n.h
@@ -59,10 +59,10 @@ std::shared_ptr<const TranslationHandler> getTranslator();
 namespace impl
 {
 inline
-Global<const TranslationHandler>& refGlobalTranslationHandler()
+FunStatGlobal<const TranslationHandler>& refGlobalTranslationHandler()
 {
     //getTranslator() may be called even after static objects of this translation unit are destroyed!
-    static Global<const TranslationHandler> inst; //external linkage even in header!
+    static FunStatGlobal<const TranslationHandler> inst; //external linkage even in header!
     return inst;
 }
 }
diff --git a/zen/legacy_compiler.h b/zen/legacy_compiler.h
index e9d50b97..16d87c53 100755
--- a/zen/legacy_compiler.h
+++ b/zen/legacy_compiler.h
@@ -7,14 +7,11 @@
 #ifndef LEGACY_COMPILER_H_839567308565656789
 #define LEGACY_COMPILER_H_839567308565656789
 
-    #include <optional>
-
 namespace std
 {
 //https://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html
 //https://isocpp.org/std/standing-documents/sd-6-sg10-feature-test-recommendations
 
-
 }
 
 #endif //LEGACY_COMPILER_H_839567308565656789
diff --git a/zen/scope_guard.h b/zen/scope_guard.h
index d056bb2a..9eff6c1f 100755
--- a/zen/scope_guard.h
+++ b/zen/scope_guard.h
@@ -10,6 +10,7 @@
 #include <cassert>
 #include <exception>
 #include "type_traits.h"
+#include "legacy_compiler.h" //std::uncaught_exceptions
 
 //best of Zen, Loki and C++17
 
@@ -103,8 +104,8 @@ auto makeGuard(F&& fun) { return ScopeGuard<runMode, std::decay_t<F>>(std::forwa
 #define ZEN_CHECK_CASE_FOR_CONSTANT_IMPL(X) L ## X
 
 
-#define ZEN_ON_SCOPE_EXIT(X)    auto ZEN_CONCAT(dummy, __LINE__) = zen::makeGuard<zen::ScopeGuardRunMode::ON_EXIT   >([&]{ X; }); (void)ZEN_CONCAT(dummy, __LINE__);
-#define ZEN_ON_SCOPE_FAIL(X)    auto ZEN_CONCAT(dummy, __LINE__) = zen::makeGuard<zen::ScopeGuardRunMode::ON_FAIL   >([&]{ X; }); (void)ZEN_CONCAT(dummy, __LINE__);
-#define ZEN_ON_SCOPE_SUCCESS(X) auto ZEN_CONCAT(dummy, __LINE__) = zen::makeGuard<zen::ScopeGuardRunMode::ON_SUCCESS>([&]{ X; }); (void)ZEN_CONCAT(dummy, __LINE__);
+#define ZEN_ON_SCOPE_EXIT(X)    auto ZEN_CONCAT(scopeGuard, __LINE__) = zen::makeGuard<zen::ScopeGuardRunMode::ON_EXIT   >([&]{ X; }); (void)ZEN_CONCAT(scopeGuard, __LINE__);
+#define ZEN_ON_SCOPE_FAIL(X)    auto ZEN_CONCAT(scopeGuard, __LINE__) = zen::makeGuard<zen::ScopeGuardRunMode::ON_FAIL   >([&]{ X; }); (void)ZEN_CONCAT(scopeGuard, __LINE__);
+#define ZEN_ON_SCOPE_SUCCESS(X) auto ZEN_CONCAT(scopeGuard, __LINE__) = zen::makeGuard<zen::ScopeGuardRunMode::ON_SUCCESS>([&]{ X; }); (void)ZEN_CONCAT(scopeGuard, __LINE__);
 
 #endif //SCOPE_GUARD_H_8971632487321434
diff --git a/zen/shell_execute.h b/zen/shell_execute.h
index 0802fbcb..98824d70 100755
--- a/zen/shell_execute.h
+++ b/zen/shell_execute.h
@@ -39,7 +39,7 @@ void shellExecute(const Zstring& command, ExecutionType type) //throw FileError
     if (type == ExecutionType::SYNC)
     {
         //Posix ::system() - execute a shell command
-        const int rv = ::system(command.c_str()); //do NOT use std::system as its documentation says nothing about "WEXITSTATUS(rv)", ect...
+        const int rv = ::system(command.c_str()); //do NOT use std::system as its documentation says nothing about "WEXITSTATUS(rv)", etc...
         if (rv == -1 || WEXITSTATUS(rv) == 127)
             throw FileError(_("Incorrect command line:") + L"\n" + utfTo<std::wstring>(command));
         //http://linux.die.net/man/3/system    "In case /bin/sh could not be executed, the exit status will be that of a command that does exit(127)"
@@ -73,7 +73,7 @@ void shellExecute(const Zstring& command, ExecutionType type) //throw FileError
 inline
 void openWithDefaultApplication(const Zstring& itemPath) //throw FileError
 {
-    shellExecute("xdg-open \"" + itemPath + "\"", ExecutionType::ASYNC); //
+    shellExecute("xdg-open \"" + itemPath +  '"', ExecutionType::ASYNC); //
 }
 }
 
diff --git a/zen/socket.h b/zen/socket.h
index e551a5ba..33ac2e50 100755
--- a/zen/socket.h
+++ b/zen/socket.h
@@ -20,6 +20,12 @@ namespace zen
     do { const ErrorCode ecInternal = getLastError(); throw SysError(formatSystemError(functionName, ecInternal)); } while (false)
 
 
+//patch up socket portability:
+using SocketType = int;
+const SocketType invalidSocket = -1;
+inline void closeSocket(SocketType s) { ::close(s); }
+
+
 //Winsock needs to be initialized before calling any of these functions! (WSAStartup/WSACleanup)
 
 class Socket //throw SysError
@@ -67,18 +73,78 @@ public:
 
     ~Socket() { closeSocket(socket_); }
 
-    using SocketType = int;
     SocketType get() const { return socket_; }
 
 private:
     Socket           (const Socket&) = delete;
     Socket& operator=(const Socket&) = delete;
 
-    static const SocketType invalidSocket = -1;
-    static void closeSocket(SocketType s) { ::close(s); }
-
     SocketType socket_ = invalidSocket;
 };
+
+
+//more socket helper functions:
+namespace
+{
+size_t tryReadSocket(SocketType socket, void* buffer, size_t bytesToRead) //throw SysError; may return short, only 0 means EOF!
+{
+    if (bytesToRead == 0) //"read() with a count of 0 returns zero" => indistinguishable from end of file! => check!
+        throw std::logic_error("Contract violation! " + std::string(__FILE__) + ":" + numberTo<std::string>(__LINE__));
+
+    int bytesReceived = 0;
+    for (;;)
+    {
+        bytesReceived = ::recv(socket,                        //_In_  SOCKET s,
+                               static_cast<char*>(buffer),    //_Out_ char   *buf,
+                               static_cast<int>(bytesToRead), //_In_  int    len,
+                               0);                            //_In_  int    flags
+        if (bytesReceived >= 0 || errno != EINTR)
+            break;
+    }
+    if (bytesReceived < 0)
+        THROW_LAST_SYS_ERROR_WSA(L"recv");
+
+    if (static_cast<size_t>(bytesReceived) > bytesToRead) //better safe than sorry
+        throw SysError(L"HttpInputStream::tryRead: buffer overflow.");
+
+    return bytesReceived; //"zero indicates end of file"
+}
+
+
+size_t tryWriteSocket(SocketType socket, const void* buffer, size_t bytesToWrite) //throw SysError; may return short! CONTRACT: bytesToWrite > 0
+{
+    if (bytesToWrite == 0)
+        throw std::logic_error("Contract violation! " + std::string(__FILE__) + ":" + numberTo<std::string>(__LINE__));
+
+    int bytesWritten = 0;
+    for (;;)
+    {
+        bytesWritten = ::send(socket,                        //_In_       SOCKET s,
+                              static_cast<const char*>(buffer), //_In_ const char   *buf,
+                              static_cast<int>(bytesToWrite),   //_In_       int    len,
+                              0);                               //_In_       int    flags
+        if (bytesWritten >= 0 || errno != EINTR)
+            break;
+    }
+    if (bytesWritten < 0)
+        THROW_LAST_SYS_ERROR_WSA(L"send");
+    if (bytesWritten > static_cast<int>(bytesToWrite))
+        throw SysError(L"send: buffer overflow.");
+    if (bytesWritten == 0)
+        throw SysError(L"send: zero bytes processed");
+
+    return bytesWritten;
+}
+}
+
+
+inline
+void shutdownSocketSend(SocketType socket) //throw SysError
+{
+    if (::shutdown(socket, SHUT_WR) != 0)
+        THROW_LAST_SYS_ERROR_WSA(L"shutdown");
+}
+
 }
 
 #endif //SOCKET_H_23498325972583947678456437
diff --git a/zen/stl_tools.h b/zen/stl_tools.h
index be9bf710..c3a9bf8f 100755
--- a/zen/stl_tools.h
+++ b/zen/stl_tools.h
@@ -12,6 +12,7 @@
 #include <vector>
 #include <memory>
 #include <algorithm>
+#include <optional>
 #include "string_traits.h"
 #include "build_info.h"
 
diff --git a/zen/string_tools.h b/zen/string_tools.h
index 8746722a..657c70d5 100755
--- a/zen/string_tools.h
+++ b/zen/string_tools.h
@@ -26,32 +26,30 @@ template <class Char> bool isWhiteSpace(Char c);
 template <class Char> bool isDigit     (Char c); //not exactly the same as "std::isdigit" -> we consider '0'-'9' only!
 template <class Char> bool isHexDigit  (Char c);
 template <class Char> bool isAsciiAlpha(Char c);
+template <class Char> bool isAsciiString(const Char* str);
 template <class Char> Char asciiToLower(Char c);
 template <class Char> Char asciiToUpper(Char c);
 
-//case-sensitive comparison (compile-time correctness:  use different number of arguments as STL comparison predicates!)
-struct CmpBinary { template <class Char> int operator()(const Char* lhs, size_t lhsLen, const Char* rhs, size_t rhsLen) const; };
+//both S and T can be strings or char/wchar_t arrays or single char/wchar_t
+template <class S, class T> bool contains(const S& str, const T& term);
 
-//basic case-insensitive comparison (considering A-Z only!)
-struct CmpAsciiNoCase { template <class Char> int operator()(const Char* lhs, size_t lhsLen, const Char* rhs, size_t rhsLen) const; };
+template <class S, class T> bool startsWith           (const S& str, const T& prefix);
+template <class S, class T> bool startsWithAsciiNoCase(const S& str, const T& prefix);
 
-struct LessAsciiNoCase
-{
-    template <class S> //don't support heterogenous input! => use as container predicate only!
-    bool operator()(const S& lhs, const S& rhs) const { return CmpAsciiNoCase()(strBegin(lhs), strLength(lhs), strBegin(rhs), strLength(rhs)) < 0; }
-};
+template <class S, class T> bool endsWith           (const S& str, const T& postfix);
+template <class S, class T> bool endsWithAsciiNoCase(const S& str, const T& postfix);
 
-//both S and T can be strings or char/wchar_t arrays or simple char/wchar_t
-template <class S, class T> bool contains(const S& str, const T& term);
+template <class S, class T> bool equalString     (const S& lhs, const T& rhs);
+template <class S, class T> bool equalAsciiNoCase(const S& lhs, const T& rhs);
 
-template <class S, class T>                 bool startsWith(const S& str, const T& prefix);
-template <class S, class T, class Function> bool startsWith(const S& str, const T& prefix,  Function cmpStringFun);
+template <class S, class T> int compareString     (const S& lhs, const T& rhs);
+template <class S, class T> int compareAsciiNoCase(const S& lhs, const T& rhs); //basic case-insensitive comparison (considering A-Z only!)
 
-template <class S, class T>                 bool endsWith  (const S& str, const T& postfix);
-template <class S, class T, class Function> bool endsWith  (const S& str, const T& postfix, Function cmpStringFun);
+struct LessAsciiNoCase //STL container predicate
+{
+    template <class S> bool operator()(const S& lhs, const S& rhs) const { return compareAsciiNoCase(lhs, rhs) < 0; }
+};
 
-template <class S, class T>                 bool strEqual(const S& lhs, const T& rhs);
-template <class S, class T, class Function> bool strEqual(const S& lhs, const T& rhs, Function cmpStringFun);
 
 enum FailureReturnVal
 {
@@ -152,6 +150,17 @@ bool isAsciiAlpha(Char c)
 
 
 template <class Char> inline
+bool isAsciiString(const Char* str)
+{
+    static_assert(std::is_same_v<Char, char> || std::is_same_v<Char, wchar_t>);
+    for (Char c = *str; c != 0; c = *++str)
+        if (zen::makeUnsigned(c) >= 128)
+            return false;
+    return true;
+}
+
+
+template <class Char> inline
 Char asciiToLower(Char c)
 {
     if (static_cast<Char>('A') <= c && c <= static_cast<Char>('Z'))
@@ -169,41 +178,103 @@ Char asciiToUpper(Char c)
 }
 
 
-template <class S, class T, class Function> inline
-bool startsWith(const S& str, const T& prefix, Function cmpStringFun)
+namespace impl
+{
+inline int strcmpWithNulls(const char*    ptr1, const char*    ptr2, size_t num) { return std:: memcmp(ptr1, ptr2, num); } //support embedded 0, unlike strncmp/wcsncmp!
+inline int strcmpWithNulls(const wchar_t* ptr1, const wchar_t* ptr2, size_t num) { return std::wmemcmp(ptr1, ptr2, num); } //
+
+
+template <class Char> inline
+int strcmpAsciiNoCase(const Char* lhs, const Char* rhs, size_t len)
+{
+    while (len-- > 0)
+    {
+        const Char charL = asciiToLower(*lhs++); //ordering: lower-case chars have higher code points than uppper-case
+        const Char charR = asciiToLower(*rhs++); //
+        if (charL != charR)
+            return static_cast<unsigned int>(charL) - static_cast<unsigned int>(charR); //unsigned char-comparison is the convention!
+        //unsigned underflow is well-defined!
+    }
+    return 0;
+}
+}
+
+
+template <class S, class T> inline
+bool startsWith(const S& str, const T& prefix)
 {
     const size_t pfLen = strLength(prefix);
-    if (strLength(str) < pfLen)
-        return false;
+    return strLength(str) >= pfLen && impl::strcmpWithNulls(strBegin(str), strBegin(prefix), pfLen) == 0;
+}
+
 
-    return cmpStringFun(strBegin(str),    pfLen,
-                        strBegin(prefix), pfLen) == 0;
+template <class S, class T> inline
+bool startsWithAsciiNoCase(const S& str, const T& prefix)
+{
+    const size_t pfLen = strLength(prefix);
+    return strLength(str) >= pfLen && impl::strcmpAsciiNoCase(strBegin(str), strBegin(prefix), pfLen) == 0;
 }
 
 
-template <class S, class T, class Function> inline
-bool endsWith(const S& str, const T& postfix, Function cmpStringFun)
+template <class S, class T> inline
+bool endsWith(const S& str, const T& postfix)
 {
     const size_t strLen = strLength(str);
     const size_t pfLen  = strLength(postfix);
-    if (strLen < pfLen)
-        return false;
+    return strLen >= pfLen && impl::strcmpWithNulls(strBegin(str) + strLen - pfLen, strBegin(postfix), pfLen) == 0;
+}
+
+
+template <class S, class T> inline
+bool endsWithAsciiNoCase(const S& str, const T& postfix)
+{
+    const size_t strLen = strLength(str);
+    const size_t pfLen  = strLength(postfix);
+    return strLen >= pfLen && impl::strcmpAsciiNoCase(strBegin(str) + strLen - pfLen, strBegin(postfix), pfLen) == 0;
+}
+
 
-    return cmpStringFun(strBegin(str) + strLen - pfLen, pfLen,
-                        strBegin(postfix), pfLen) == 0;
+template <class S, class T> inline
+bool equalString(const S& lhs, const T& rhs)
+{
+    const size_t lhsLen = strLength(lhs);
+    return lhsLen == strLength(rhs) && impl::strcmpWithNulls(strBegin(lhs), strBegin(rhs), lhsLen) == 0;
 }
 
 
-template <class S, class T, class Function> inline
-bool strEqual(const S& lhs, const T& rhs, Function cmpStringFun)
+template <class S, class T> inline
+bool equalAsciiNoCase(const S& lhs, const T& rhs)
+{
+    const size_t lhsLen = strLength(lhs);
+    return lhsLen == strLength(rhs) && impl::strcmpAsciiNoCase(strBegin(lhs), strBegin(rhs), lhsLen) == 0;
+}
+
+
+template <class S, class T> inline
+int compareString(const S& lhs, const T& rhs)
 {
-    return cmpStringFun(strBegin(lhs), strLength(lhs), strBegin(rhs), strLength(rhs)) == 0;
+    const size_t lhsLen = strLength(lhs);
+    const size_t rhsLen = strLength(rhs);
+
+    //length check *after* strcmpWithNulls(): we do care about natural ordering: e.g. for "compareString(makeUpperCopy(lhs), makeUpperCopy(rhs))"
+    const int rv = impl::strcmpWithNulls(strBegin(lhs), strBegin(rhs), std::min(lhsLen, rhsLen));
+    if (rv != 0)
+        return rv;
+    return static_cast<int>(lhsLen) - static_cast<int>(rhsLen);
 }
 
 
-template <class S, class T> inline bool startsWith(const S& str, const T& prefix ) { return startsWith(str, prefix,  CmpBinary()); }
-template <class S, class T> inline bool endsWith  (const S& str, const T& postfix) { return endsWith  (str, postfix, CmpBinary()); }
-template <class S, class T> inline bool strEqual  (const S& lhs, const T& rhs    ) { return strEqual  (lhs, rhs,     CmpBinary()); }
+template <class S, class T> inline
+int compareAsciiNoCase(const S& lhs, const T& rhs)
+{
+    const size_t lhsLen = strLength(lhs);
+    const size_t rhsLen = strLength(rhs);
+
+    const int rv = impl::strcmpAsciiNoCase(strBegin(lhs), strBegin(rhs), std::min(lhsLen, rhsLen));
+    if (rv != 0)
+        return rv;
+    return static_cast<int>(lhsLen) - static_cast<int>(rhsLen);
+}
 
 
 template <class S, class T> inline
@@ -464,42 +535,12 @@ struct CopyStringToString<T, T> //perf: we don't need a deep copy if string type
     template <class S>
     T copy(S&& str) const { return std::forward<S>(str); }
 };
-
-inline int strcmpWithNulls(const char*    ptr1, const char*    ptr2, size_t num) { return std::memcmp (ptr1, ptr2, num); }
-inline int strcmpWithNulls(const wchar_t* ptr1, const wchar_t* ptr2, size_t num) { return std::wmemcmp(ptr1, ptr2, num); }
 }
 
 template <class T, class S> inline
 T copyStringTo(S&& str) { return impl::CopyStringToString<std::decay_t<S>, T>().copy(std::forward<S>(str)); }
 
 
-template <class Char> inline
-int CmpBinary::operator()(const Char* lhs, size_t lhsLen, const Char* rhs, size_t rhsLen) const
-{
-    //support embedded 0, unlike strncmp/wcsncmp!
-    const int rv = impl::strcmpWithNulls(lhs, rhs, std::min(lhsLen, rhsLen));
-    if (rv != 0)
-        return rv;
-    return static_cast<int>(lhsLen) - static_cast<int>(rhsLen);
-}
-
-
-template <class Char> inline
-int CmpAsciiNoCase::operator()(const Char* lhs, size_t lhsLen, const Char* rhs, size_t rhsLen) const
-{
-    const auto* const lhsLast = lhs + std::min(lhsLen, rhsLen);
-    while (lhs != lhsLast)
-    {
-        const Char charL = asciiToLower(*lhs++); //ordering: lower-case chars have higher code points than uppper-case
-        const Char charR = asciiToLower(*rhs++); //
-        if (charL != charR)
-            return static_cast<unsigned int>(charL) - static_cast<unsigned int>(charR); //unsigned char-comparison is the convention!
-        //unsigned underflow is well-defined!
-    }
-    return static_cast<int>(lhsLen) - static_cast<int>(rhsLen);
-}
-
-
 namespace impl
 {
 template <class Num> inline
diff --git a/zen/thread.cpp b/zen/thread.cpp
index 8016d4a9..08bfaa25 100755
--- a/zen/thread.cpp
+++ b/zen/thread.cpp
@@ -34,10 +34,7 @@ uint64_t getThreadIdNative()
 }
 
 
-struct InitMainThreadIdOnStartup
-{
-    InitMainThreadIdOnStartup() { getMainThreadId(); }
-} startupInitMainThreadId;
+const uint64_t globalMainThreadId = getThreadId(); //avoid code-gen for "magic static"!
 }
 
 
@@ -50,6 +47,9 @@ uint64_t zen::getThreadId()
 
 uint64_t zen::getMainThreadId()
 {
-    static const uint64_t mainThreadId = getThreadId();
-    return mainThreadId;
+    //don't make this a function-scope static (avoid code-gen for "magic static")
+    if (globalMainThreadId == 0) //might be called during static initialization
+        return getThreadId();
+
+    return globalMainThreadId;
 }
diff --git a/zen/time.h b/zen/time.h
index b06d3d15..a32e28e3 100755
--- a/zen/time.h
+++ b/zen/time.h
@@ -327,13 +327,13 @@ TimeComp parseTime(const String& format, const String2& str, UserDefinedFormatTa
     const CharType*       itStr = strBegin(str);
     const CharType* const strLast = itStr + strLength(str);
 
-    auto extractNumber = [&](int& result, size_t digitCount) -> bool
+    auto extractNumber = [&](int& result, size_t digitCount)
     {
         if (strLast - itStr < makeSigned(digitCount))
             return false;
 
-        if (std::any_of(itStr, itStr + digitCount, [](CharType c) { return !isDigit(c); }))
-        return false;
+        if (!std::all_of(itStr, itStr + digitCount, isDigit<CharType>))
+            return false;
 
         result = zen::stringTo<int>(StringRef<const CharType>(itStr, itStr + digitCount));
         itStr += digitCount;
diff --git a/zen/type_traits.h b/zen/type_traits.h
index 2d4e7a97..8783cb6a 100755
--- a/zen/type_traits.h
+++ b/zen/type_traits.h
@@ -8,7 +8,6 @@
 #define TYPE_TRAITS_H_3425628658765467
 
 #include <type_traits>
-#include "legacy_compiler.h"
 
 //http://en.cppreference.com/w/cpp/header/type_traits
 
diff --git a/zen/utf.h b/zen/utf.h
index da6aaf97..5a095874 100755
--- a/zen/utf.h
+++ b/zen/utf.h
@@ -192,7 +192,7 @@ public:
     std::optional<CodePoint> getNext()
     {
         if (it_ == last_)
-            return std::nullopt; //GCC 8.2 bug: -Wmaybe-uninitialized for "return {};"
+            return std::nullopt;
 
         const Char8 ch = *it_++;
         CodePoint cp = ch;
@@ -313,7 +313,7 @@ bool isValidUtf(const UtfString& str)
     using namespace impl;
 
     UtfDecoder<GetCharTypeT<UtfString>> decoder(strBegin(str), strLength(str));
-    while (std::optional<CodePoint> cp = decoder.getNext())
+    while (const std::optional<CodePoint> cp = decoder.getNext())
         if (*cp == REPLACEMENT_CHAR)
             return false;
 
@@ -367,7 +367,7 @@ TargetString utfTo(const SourceString& str, std::false_type)
     TargetString output;
 
     UtfDecoder<CharSrc> decoder(strBegin(str), strLength(str));
-    while (std::optional<CodePoint> cp = decoder.getNext())
+    while (const std::optional<CodePoint> cp = decoder.getNext())
         codePointToUtf<CharTrg>(*cp, [&](CharTrg c) { output += c; });
 
     return output;
diff --git a/zen/zstring.cpp b/zen/zstring.cpp
index 8bf77a0b..68609030 100755
--- a/zen/zstring.cpp
+++ b/zen/zstring.cpp
@@ -8,9 +8,102 @@
 #include <stdexcept>
 #include "utf.h"
 
+    #include <gtk/gtk.h>
+    #include "sys_error.h"
 
 using namespace zen;
 
+
+Zstring makeUpperCopy(const Zstring& str)
+{
+    //fast pre-check:
+    if (isAsciiString(str.c_str())) //perf: in the range of 3.5ns
+    {
+        Zstring output = str;
+        for (Zchar& c : output) c = asciiToUpper(c);
+        return output;
+    }
+
+    Zstring strNorm = getUnicodeNormalForm(str);
+    try
+    {
+        static_assert(sizeof(impl::CodePoint) == sizeof(gunichar));
+        Zstring output;
+        output.reserve(strNorm.size());
+
+        impl::UtfDecoder<char> decoder(strNorm.c_str(), strNorm.size());
+        while (const std::optional<impl::CodePoint> cp = decoder.getNext())
+            impl::codePointToUtf<char>(::g_unichar_toupper(*cp), [&](char c) { output += c; }); //don't use std::towupper: *incomplete* and locale-dependent!
+
+        return output;
+
+    }
+    catch (const SysError& e)
+    {
+        (void)e;
+        assert(false);
+        return str;
+    }
+}
+
+
+Zstring getUnicodeNormalForm(const Zstring& str)
+{
+    //fast pre-check:
+    if (isAsciiString(str.c_str())) //perf: in the range of 3.5ns
+        return str; //god bless our ref-counting! => save output string memory consumption!
+
+    //Example: const char* decomposed  = "\x6f\xcc\x81";
+    //         const char* precomposed = "\xc3\xb3";
+    try
+    {
+        gchar* outStr = ::g_utf8_normalize (str.c_str(), str.length(), G_NORMALIZE_DEFAULT_COMPOSE);
+        if (!outStr)
+            throw SysError(L"g_utf8_normalize: conversion failed. (" + utfTo<std::wstring>(str) + L")");
+        ZEN_ON_SCOPE_EXIT(::g_free(outStr));
+        return outStr;
+
+    }
+    catch (const SysError& e)
+    {
+        (void)e;
+        assert(false);
+        return str;
+    }
+}
+
+
+Zstring replaceCpyAsciiNoCase(const Zstring& str, const Zstring& oldTerm, const Zstring& newTerm)
+{
+    if (oldTerm.empty())
+        return str;
+    
+    Zstring strU = str;    
+    Zstring oldU = oldTerm;
+          
+    for (Zchar& c : strU) c = asciiToUpper(c); //can't use makeUpperCopy(): input/output sizes may differ!
+    for (Zchar& c : oldU) c = asciiToUpper(c); //
+
+    Zstring output;
+
+    for (size_t pos = 0;;)
+    {
+        const size_t posFound = strU.find(oldU, pos);
+        if (posFound == Zstring::npos)
+        {
+            if (pos == 0) //optimize "oldTerm not found": return ref-counted copy
+                return str; 
+            output.append(str.begin() + pos, str.end());
+            return output;
+        }
+
+        output.append(str.begin() + pos, str.begin() + posFound);
+        output += newTerm;
+        pos = posFound + oldTerm.size();
+    }
+}
+
+
 /*
 MSDN "Handling Sorting in Your Applications": https://msdn.microsoft.com/en-us/library/windows/desktop/dd318144
 
@@ -33,8 +126,14 @@ OS X (UTF8 char)
 ________________________
 time per call | function
 */
+int compareLocalPath(const Zstring& lhs, const Zstring& rhs)
+{
+    assert(lhs.find(Zchar('\0')) == Zstring::npos); //don't expect embedded nulls!
+    assert(rhs.find(Zchar('\0')) == Zstring::npos); //
 
+    return compareString(lhs, rhs);
 
+}
 
 
 namespace
@@ -43,7 +142,7 @@ int compareNoCaseUtf8(const char* lhs, size_t lhsLen, const char* rhs, size_t rh
 {
     //- strncasecmp implements ASCII CI-comparsion only! => signature is broken for UTF8-input; toupper() similarly doesn't support Unicode
     //- wcsncasecmp: https://opensource.apple.com/source/Libc/Libc-763.12/string/wcsncasecmp-fbsd.c
-    // => re-implement comparison based on towlower() to avoid memory allocations
+    // => re-implement comparison based on g_unichar_tolower() to avoid memory allocations
 
     impl::UtfDecoder<char> decL(lhs, lhsLen);
     impl::UtfDecoder<char> decR(rhs, rhsLen);
@@ -54,23 +153,35 @@ int compareNoCaseUtf8(const char* lhs, size_t lhsLen, const char* rhs, size_t rh
         if (!cpL || !cpR)
             return static_cast<int>(!cpR) - static_cast<int>(!cpL);
 
-        //support unit-testing on Windows: CodePoint is truncated to wchar_t
-        static_assert(sizeof(wchar_t) == sizeof(impl::CodePoint));
+        static_assert(sizeof(gunichar) == sizeof(impl::CodePoint));
 
-        const wchar_t charL = ::towlower(static_cast<wchar_t>(*cpL)); //ordering: towlower() converts to higher code points than towupper()
-        const wchar_t charR = ::towlower(static_cast<wchar_t>(*cpR)); //uses LC_CTYPE category of current locale
+        const gunichar charL = ::g_unichar_toupper(*cpL); //note: tolower can be ambiguous, so don't use:
+        const gunichar charR = ::g_unichar_toupper(*cpR); //e.g. "Σ" (upper case) can be lower-case "ς" in the end of the word or "σ" in the middle.
         if (charL != charR)
+            //ordering: "to lower" converts to higher code points than "to upper"
             return static_cast<unsigned int>(charL) - static_cast<unsigned int>(charR); //unsigned char-comparison is the convention!
         //unsigned underflow is well-defined!
     }
 }
+
 }
 
 
-int cmpStringNaturalLinuxTest(const char* lhs, size_t lhsLen, const char* rhs, size_t rhsLen)
+int compareNatural(const Zstring& lhs, const Zstring& rhs)
 {
-    const char* const lhsEnd = lhs + lhsLen;
-    const char* const rhsEnd = rhs + rhsLen;
+    //Unicode normal forms:
+    //      Windows: CompareString() already ignores NFD/NFC differences: nice...
+    //      Linux:  g_unichar_toupper() can't ignore differences
+    //      macOS:  CFStringCompare() considers differences
+
+    const Zstring& lhsNorm = getUnicodeNormalForm(lhs);
+    const Zstring& rhsNorm = getUnicodeNormalForm(rhs);
+
+    const char* strL = lhsNorm.c_str();
+    const char* strR = rhsNorm.c_str();
+
+    const char* const strEndL = strL + lhsNorm.size();
+    const char* const strEndR = strR + rhsNorm.size();
     /*
         - compare strings after conceptually creating blocks of whitespace/numbers/text
         - implement strict weak ordering!
@@ -84,43 +195,43 @@ int cmpStringNaturalLinuxTest(const char* lhs, size_t lhsLen, const char* rhs, s
     */
     for (;;)
     {
-        if (lhs == lhsEnd || rhs == rhsEnd)
-            return static_cast<int>(lhs != lhsEnd) - static_cast<int>(rhs != rhsEnd); //"nothing" before "something"
+        if (strL == strEndL || strR == strEndR)
+            return static_cast<int>(strL != strEndL) - static_cast<int>(strR != strEndR); //"nothing" before "something"
         //note: "something" never would have been condensed to "nothing" further below => can finish evaluation here
 
-        const bool wsL = isWhiteSpace(*lhs);
-        const bool wsR = isWhiteSpace(*rhs);
+        const bool wsL = isWhiteSpace(*strL);
+        const bool wsR = isWhiteSpace(*strR);
         if (wsL != wsR)
             return static_cast<int>(!wsL) - static_cast<int>(!wsR); //whitespace before non-ws!
         if (wsL)
         {
-            ++lhs, ++rhs;
-            while (lhs != lhsEnd && isWhiteSpace(*lhs)) ++lhs;
-            while (rhs != rhsEnd && isWhiteSpace(*rhs)) ++rhs;
+            ++strL, ++strR;
+            while (strL != strEndL && isWhiteSpace(*strL)) ++strL;
+            while (strR != strEndR && isWhiteSpace(*strR)) ++strR;
             continue;
         }
 
-        const bool digitL = isDigit(*lhs);
-        const bool digitR = isDigit(*rhs);
+        const bool digitL = isDigit(*strL);
+        const bool digitR = isDigit(*strR);
         if (digitL != digitR)
             return static_cast<int>(!digitL) - static_cast<int>(!digitR); //number before chars!
         if (digitL)
         {
-            while (lhs != lhsEnd && *lhs == '0') ++lhs;
-            while (rhs != rhsEnd && *rhs == '0') ++rhs;
+            while (strL != strEndL && *strL == '0') ++strL;
+            while (strR != strEndR && *strR == '0') ++strR;
 
             int rv = 0;
-            for (;; ++lhs, ++rhs)
+            for (;; ++strL, ++strR)
             {
-                const bool endL = lhs == lhsEnd || !isDigit(*lhs);
-                const bool endR = rhs == rhsEnd || !isDigit(*rhs);
+                const bool endL = strL == strEndL || !isDigit(*strL);
+                const bool endR = strR == strEndR || !isDigit(*strR);
                 if (endL != endR)
                     return static_cast<int>(!endL) - static_cast<int>(!endR); //more digits means bigger number
                 if (endL)
                     break; //same number of digits
 
-                if (rv == 0 && *lhs != *rhs)
-                    rv = *lhs - *rhs; //found first digit difference comparing from left
+                if (rv == 0 && *strL != *strR)
+                    rv = *strL - *strR; //found first digit difference comparing from left
             }
             if (rv != 0)
                 return rv;
@@ -128,28 +239,19 @@ int cmpStringNaturalLinuxTest(const char* lhs, size_t lhsLen, const char* rhs, s
         }
 
         //compare full junks of text: consider unicode encoding!
-        const char* textBeginL = lhs++;
-        const char* textBeginR = rhs++; //current char is neither white space nor digit at this point!
-        while (lhs != lhsEnd && !isWhiteSpace(*lhs) && !isDigit(*lhs)) ++lhs;
-        while (rhs != rhsEnd && !isWhiteSpace(*rhs) && !isDigit(*rhs)) ++rhs;
+        const char* textBeginL = strL++;
+        const char* textBeginR = strR++; //current char is neither white space nor digit at this point!
+        while (strL != strEndL && !isWhiteSpace(*strL) && !isDigit(*strL)) ++strL;
+        while (strR != strEndR && !isWhiteSpace(*strR) && !isDigit(*strR)) ++strR;
 
-        const int rv = compareNoCaseUtf8(textBeginL, lhs - textBeginL, textBeginR, rhs - textBeginR);
+        const int rv = compareNoCaseUtf8(textBeginL, strL - textBeginL, textBeginR, strR - textBeginR);
         if (rv != 0)
             return rv;
     }
-}
-
 
-namespace
-{
 }
 
 
-int CmpNaturalSort::operator()(const Zchar* lhs, size_t lhsLen, const Zchar* rhs, size_t rhsLen) const
-{
-    //auto strL = utfTo<std::string>(Zstring(lhs, lhsLen));
-    //auto strR = utfTo<std::string>(Zstring(rhs, rhsLen));
-    //return cmpStringNaturalLinux(strL.c_str(), strL.size(), strR.c_str(), strR.size());
-    return cmpStringNaturalLinux(lhs, lhsLen, rhs, rhsLen);
-
-}
\ No newline at end of file
+warn_static("clean up implementation of these two:")
+//template <> inline bool isWhiteSpace(char c)
+//template <> inline bool isWhiteSpace(wchar_t c)
diff --git a/zen/zstring.h b/zen/zstring.h
index 7fa21335..20cf968d 100755
--- a/zen/zstring.h
+++ b/zen/zstring.h
@@ -14,6 +14,7 @@
     #define Zstr(x) x
     const Zchar FILE_NAME_SEPARATOR = '/';
 
+
 //"The reason for all the fuss above" - Loki/SmartPtr
 //a high-performance string for interfacing with native OS APIs in multithreaded contexts
 using Zstring = zen::Zbase<Zchar>;
@@ -22,43 +23,71 @@ using Zstring = zen::Zbase<Zchar>;
 using Zstringw = zen::Zbase<wchar_t>;
 
 
-//Compare filepaths: Windows/OS X does NOT distinguish between upper/lower-case, while Linux DOES
-struct CmpFilePath
-{
-    int operator()(const Zchar* lhs, size_t lhsLen, const Zchar* rhs, size_t rhsLen) const;
-};
+//Caveat: don't expect input/output string sizes to match:
+// - different UTF-8 encoding length of upper-case chars
+// - different number of upper case chars (e.g. "ß" => "SS" on macOS)
+// - output is Unicode-normalized
+Zstring makeUpperCopy(const Zstring& str);
 
-struct CmpNaturalSort
-{
-    int operator()(const Zchar* lhs, size_t lhsLen, const Zchar* rhs, size_t rhsLen) const;
-};
+//Windows, Linux: precomposed
+//macOS: decomposed
+Zstring getUnicodeNormalForm(const Zstring& str);
 
+Zstring replaceCpyAsciiNoCase(const Zstring& str, const Zstring& oldTerm, const Zstring& newTerm);
 
-struct LessFilePath
-{
-    template <class S> //don't support heterogenous input! => use as container predicate only!
-    bool operator()(const S& lhs, const S& rhs) const { using namespace zen; return CmpFilePath()(strBegin(lhs), strLength(lhs), strBegin(rhs), strLength(rhs)) < 0; }
-};
+//------------------------------------------------------------------------------------------
+//inline
+//int compareNoCase(const Zstring& lhs, const Zstring& rhs)
+//{
+//    return zen::compareString(makeUpperCopy(lhs), makeUpperCopy(rhs));
+//    //avoid eager optimization bugs: e.g. "if (isAsciiString()) compareAsciiNoCase()" might model a different order!
+//}
+
+inline bool equalNoCase(const Zstring& lhs, const Zstring& rhs) { return makeUpperCopy(lhs) == makeUpperCopy(rhs); }
 
-struct LessNaturalSort
+struct ZstringNoCase //use as STL container key: avoid needless upper-case conversions during std::map<>::find()
 {
-    template <class S> //don't support heterogenous input! => use as container predicate only!
-    bool operator()(const S& lhs, const S& rhs) const { using namespace zen; return CmpNaturalSort()(strBegin(lhs), strLength(lhs), strBegin(rhs), strLength(rhs)) < 0; }
+        ZstringNoCase(const Zstring& str) : upperCase(makeUpperCopy(str)) {}
+        Zstring upperCase;
 };
+inline bool operator<(const ZstringNoCase& lhs, const ZstringNoCase& rhs) { return lhs.upperCase < rhs.upperCase; } 
+
+//struct LessNoCase { bool operator()(const Zstring& lhs, const Zstring& rhs) const { return compareNoCase(lhs, rhs) < 0; } };
+
+//------------------------------------------------------------------------------------------
+
+//Compare *local* file paths:
+//  Windows: igore case
+//  Linux:   byte-wise comparison
+//  macOS:   igore case + Unicode normalization forms
+int compareLocalPath(const Zstring& lhs, const Zstring& rhs);
+
+inline bool equalLocalPath(const Zstring& lhs, const Zstring& rhs) { return compareLocalPath(lhs, rhs) == 0;  }
 
+struct LessLocalPath { bool operator()(const Zstring& lhs, const Zstring& rhs) const { return compareLocalPath(lhs, rhs) < 0;  } };
 
-template <class S>
-S makeUpperCopy(S str);
+//------------------------------------------------------------------------------------------
+int compareNatural(const Zstring& lhs, const Zstring& rhs);
 
+struct LessNaturalSort { bool operator()(const Zstring& lhs, const Zstring rhs) const { return compareNatural(lhs, rhs) < 0; } };
+//------------------------------------------------------------------------------------------
+
+warn_static("get rid:")
+inline int compareFilePath(const Zstring& lhs, const Zstring& rhs) { return compareLocalPath(lhs, rhs); }
+
+inline bool equalFilePath(const Zstring& lhs, const Zstring& rhs) { return compareLocalPath(lhs, rhs) == 0; }
+
+struct LessFilePath { bool operator()(const Zstring& lhs, const Zstring& rhs) const { return compareLocalPath(lhs, rhs) < 0; } };
+//------------------------------------------------------------------------------------------
 
-template <class S, class T> inline
-bool equalFilePath(const S& lhs, const T& rhs) { using namespace zen; return strEqual(lhs, rhs, CmpFilePath());  }
 
 
 inline
 Zstring appendSeparator(Zstring path) //support rvalue references!
 {
-    return zen::endsWith(path, FILE_NAME_SEPARATOR) ? path : (path += FILE_NAME_SEPARATOR); //returning a by-value parameter implicitly converts to r-value!
+    if (!zen::endsWith(path, FILE_NAME_SEPARATOR))
+        path += FILE_NAME_SEPARATOR;
+    return path; //returning a by-value parameter => RVO if possible, r-value otherwise!
 }
 
 
@@ -82,12 +111,7 @@ Zstring getFileExtension(const Zstring& filePath)
 }
 
 
-template <class S, class T, class U>
-S ciReplaceCpy(const S& str, const T& oldTerm, const U& newTerm);
-
-
-
-//common unicode sequences
+//common unicode characters
 const wchar_t EM_DASH = L'\u2014';
 const wchar_t EN_DASH = L'\u2013';
 const wchar_t* const SPACED_DASH = L" \u2013 "; //using 'EN DASH'
@@ -99,89 +123,6 @@ const wchar_t MULT_SIGN = L'\u00D7'; //fancy "x"
 
 
 
-
-
-//################################# inline implementation ########################################
-inline
-void makeUpperInPlace(wchar_t* str, size_t strLen)
-{
-    std::for_each(str, str + strLen, [](wchar_t& c) { c = std::towupper(c); }); //locale-dependent!
-}
-
-
-inline
-void makeUpperInPlace(char* str, size_t strLen)
-{
-    std::for_each(str, str + strLen, [](char& c) { c = std::toupper(static_cast<unsigned char>(c)); }); //locale-dependent!
-    //result of toupper() is an unsigned char mapped to int range: the char representation is in the last 8 bits and we need not care about signedness!
-    //this should work for UTF-8, too: all chars >= 128 are mapped upon themselves!
-}
-
-
-template <class S> inline
-S makeUpperCopy(S str)
-{
-    const size_t len = str.length(); //we assert S is a string type!
-    if (len > 0)
-        makeUpperInPlace(&*str.begin(), len);
-
-    return str;
-}
-
-
-inline
-int CmpFilePath::operator()(const Zchar* lhs, size_t lhsLen, const Zchar* rhs, size_t rhsLen) const
-{
-    assert(std::find(lhs, lhs + lhsLen, 0) == lhs + lhsLen); //don't expect embedded nulls!
-    assert(std::find(rhs, rhs + rhsLen, 0) == rhs + rhsLen); //
-
-    const int rv = std::strncmp(lhs, rhs, std::min(lhsLen, rhsLen));
-    if (rv != 0)
-        return rv;
-    return static_cast<int>(lhsLen) - static_cast<int>(rhsLen);
-}
-
-
-template <class S, class T, class U> inline
-S ciReplaceCpy(const S& str, const T& oldTerm, const U& newTerm)
-{
-    using namespace zen;
-    static_assert(std::is_same_v<GetCharTypeT<S>, GetCharTypeT<T>>);
-    static_assert(std::is_same_v<GetCharTypeT<T>, GetCharTypeT<U>>);
-    const size_t oldLen = strLength(oldTerm);
-    if (oldLen == 0)
-        return str;
-
-    const S strU = makeUpperCopy(str); //S required to be a string class
-    const S oldU = makeUpperCopy<S>(oldTerm); //[!] T not required to be a string class
-    assert(strLength(strU) == strLength(str    ));
-    assert(strLength(oldU) == strLength(oldTerm));
-
-    const auto* const newBegin = strBegin(newTerm);
-    const auto* const newEnd   = newBegin + strLength(newTerm);
-
-    S output;
-
-    for (size_t pos = 0;;)
-    {
-        const auto itFound = std::search(strU.begin() + pos, strU.end(),
-                                         oldU.begin(), oldU.end());
-        if (itFound == strU.end() && pos == 0)
-            return str; //optimize "oldTerm not found": return ref-counted copy
-
-        impl::stringAppend(output, str.begin() + pos, str.begin() + (itFound - strU.begin()));
-        if (itFound == strU.end())
-            return output;
-
-        impl::stringAppend(output, newBegin, newEnd);
-        pos = (itFound - strU.begin()) + oldLen;
-    }
-}
-
-//expose for unit tests
-int cmpStringNaturalLinuxTest(const char* lhs, size_t lhsLen, const char* rhs, size_t rhsLen);
-inline int cmpStringNaturalLinux(const char* lhs, size_t lhsLen, const char* rhs, size_t rhsLen) { return cmpStringNaturalLinuxTest(lhs, lhsLen, rhs, rhsLen); }
-
 //---------------------------------------------------------------------------
 //ZEN macro consistency checks:
 
diff --git a/zenXml/zenxml/cvrt_text.h b/zenXml/zenxml/cvrt_text.h
index c6dab8c2..51b23173 100755
--- a/zenXml/zenxml/cvrt_text.h
+++ b/zenXml/zenxml/cvrt_text.h
@@ -22,9 +22,9 @@ It is \b not required to call these functions directly. They are implicitly used
 zen::XmlElement::setValue(), zen::XmlElement::getAttribute() and zen::XmlElement::setAttribute().
 \n\n
 Conversions for the following user types are supported by default:
-    - strings - std::string, std::wstring, char*, wchar_t*, char, wchar_t, ect..., all STL-compatible-string-classes
-    - numbers - int, double, float, bool, long, ect..., all built-in numbers
-    - STL containers - std::map, std::set, std::vector, std::list, ect..., all STL-compatible-containers
+    - strings - std::string, std::wstring, char*, wchar_t*, char, wchar_t, etc..., all STL-compatible-string-classes
+    - numbers - int, double, float, bool, long, etc..., all built-in numbers
+    - STL containers - std::map, std::set, std::vector, std::list, etc..., all STL-compatible-containers
     - std::pair
 
 You can add support for additional types via template specialization. \n\n
diff --git a/zenXml/zenxml/parser.h b/zenXml/zenxml/parser.h
index a3975297..a90d163a 100755
--- a/zenXml/zenxml/parser.h
+++ b/zenXml/zenxml/parser.h
@@ -11,7 +11,6 @@
 #include <cstddef> //ptrdiff_t; req. on Linux
 #include <zen/string_tools.h>
 #include "dom.h"
-#include "error.h"
 
 
 namespace zen
@@ -28,12 +27,13 @@ namespace zen
 \param indent Indentation, default: four space characters
 \return Output byte stream
 */
-std::string serialize(const XmlDoc& doc,
-                      const std::string& lineBreak = "\r\n",
-                      const std::string& indent = "    "); //noexcept
+std::string serializeXml(const XmlDoc& doc,
+                         const std::string& lineBreak = "\r\n",
+                         const std::string& indent    = "    "); //noexcept
+
 
 ///Exception thrown due to an XML parsing error
-struct XmlParsingError : public XmlError
+struct XmlParsingError
 {
     XmlParsingError(size_t rowNo, size_t colNo) : row(rowNo), col(colNo) {}
     ///Input file row where the parsing error occured (zero-based)
@@ -42,14 +42,13 @@ struct XmlParsingError : public XmlError
     const size_t col; //
 };
 
-
 ///Load XML document from a byte stream
 /**
 \param stream Input byte stream
 \returns Output XML document
 \throw XmlParsingError
 */
-XmlDoc parse(const std::string& stream); //throw XmlParsingError
+XmlDoc parseXml(const std::string& stream); //throw XmlParsingError
 
 
 
@@ -71,9 +70,9 @@ XmlDoc parse(const std::string& stream); //throw XmlParsingError
 
 
 //---------------------------- implementation ----------------------------
-//see: http://www.w3.org/TR/xml/
+//see: https://www.w3.org/TR/xml/
 
-namespace impl
+namespace xml_impl
 {
 template <class Predicate> inline
 std::string normalize(const std::string& str, Predicate pred) //pred: unary function taking a char, return true if value shall be encoded as hex
@@ -91,7 +90,7 @@ std::string normalize(const std::string& str, Predicate pred) //pred: unary func
         {
             if (c == '\'')
                 output += "&apos;";
-            else if (c == '\"')
+            else if (c == '"')
                 output += "&quot;";
             else
             {
@@ -111,7 +110,7 @@ std::string normalize(const std::string& str, Predicate pred) //pred: unary func
 inline
 std::string normalizeName(const std::string& str)
 {
-    const std::string nameFmt = normalize(str, [](char c) { return isWhiteSpace(c) || c == '=' || c == '/' || c == '\'' || c == '\"'; });
+    const std::string nameFmt = normalize(str, [](char c) { return isWhiteSpace(c) || c == '=' || c == '/' || c == '\'' || c == '"'; });
     assert(!nameFmt.empty());
     return nameFmt;
 }
@@ -125,7 +124,7 @@ std::string normalizeElementValue(const std::string& str)
 inline
 std::string normalizeAttribValue(const std::string& str)
 {
-    return normalize(str, [](char c) { return static_cast<unsigned char>(c) < 32 || c == '\'' || c == '\"'; });
+    return normalize(str, [](char c) { return static_cast<unsigned char>(c) < 32 || c == '\'' || c == '"'; });
 }
 
 
@@ -163,10 +162,12 @@ std::string denormalize(const std::string& str)
             else if (checkEntity(it, str.end(), "&apos;"))
                 output += '\'';
             else if (checkEntity(it, str.end(), "&quot;"))
-                output += '\"';
+                output += '"';
             else if (str.end() - it >= 6 &&
                      it[1] == '#' &&
                      it[2] == 'x' &&
+                     isHexDigit(it[3]) &&
+                     isHexDigit(it[4]) &&
                      it[5] == ';')
             {
                 output += unhexify(it[3], it[4]);
@@ -203,7 +204,7 @@ void serialize(const XmlElement& element, std::string& stream,
 
     auto attr = element.getAttributes();
     for (auto it = attr.first; it != attr.second; ++it)
-        stream += ' ' + normalizeName(it->name) + "=\"" + normalizeAttribValue(it->value) + '\"';
+        stream += ' ' + normalizeName(it->name) + "=\"" + normalizeAttribValue(it->value) + '"';
 
     auto iterPair = element.getChildren();
     if (iterPair.first != iterPair.second) //structured element
@@ -229,34 +230,30 @@ void serialize(const XmlElement& element, std::string& stream,
             stream += "/>" + lineBreak;
     }
 }
+}
+}
 
-std::string serialize(const XmlDoc& doc,
-                      const std::string& lineBreak,
-                      const std::string& indent)
+inline
+std::string serializeXml(const XmlDoc& doc,
+                         const std::string& lineBreak,
+                         const std::string& indent)
 {
     std::string version = doc.getVersionAs<std::string>();
     if (!version.empty())
-        version = " version=\"" + normalizeAttribValue(version) + '\"';
+        version = " version=\"" + xml_impl::normalizeAttribValue(version) + '"';
 
     std::string encoding = doc.getEncodingAs<std::string>();
     if (!encoding.empty())
-        encoding = " encoding=\"" + normalizeAttribValue(encoding) + '\"';
+        encoding = " encoding=\"" + xml_impl::normalizeAttribValue(encoding) + '"';
 
     std::string standalone = doc.getStandaloneAs<std::string>();
     if (!standalone.empty())
-        standalone = " standalone=\"" + normalizeAttribValue(standalone) + '\"';
+        standalone = " standalone=\"" + xml_impl::normalizeAttribValue(standalone) + '"';
 
     std::string output = "<?xml" + version + encoding + standalone + "?>" + lineBreak;
-    serialize(doc.root(), output, lineBreak, indent, 0);
+    xml_impl::serialize(doc.root(), output, lineBreak, indent, 0);
     return output;
 }
-}
-}
-
-inline
-std::string serialize(const XmlDoc& doc,
-                      const std::string& lineBreak,
-                      const std::string& indent) { return impl::serialize(doc, lineBreak, indent); }
 
 /*
 Grammar for XML parser
@@ -282,7 +279,7 @@ pm-expression:
     element-list-expression
 */
 
-namespace impl
+namespace xml_impl
 {
 struct Token
 {
@@ -310,53 +307,53 @@ struct Token
 class Scanner
 {
 public:
-    Scanner(const std::string& stream) : stream_(stream), pos(stream_.begin())
+    Scanner(const std::string& stream) : stream_(stream), pos_(stream_.begin())
     {
         if (zen::startsWith(stream_, BYTE_ORDER_MARK_UTF8))
-            pos += strLength(BYTE_ORDER_MARK_UTF8);
+            pos_ += strLength(BYTE_ORDER_MARK_UTF8);
     }
 
-    Token nextToken() //throw XmlParsingError
+    Token getNextToken() //throw XmlParsingError
     {
         //skip whitespace
-        pos = std::find_if(pos, stream_.end(), [](char c) { return !zen::isWhiteSpace(c); });
+        pos_ = std::find_if(pos_, stream_.end(), std::not_fn(isWhiteSpace<char>));
 
-        if (pos == stream_.end())
+        if (pos_ == stream_.end())
             return Token::TK_END;
 
         //skip XML comments
-        if (startsWith(xmlCommentBegin))
+        if (startsWith(xmlCommentBegin_))
         {
-            auto it = std::search(pos + xmlCommentBegin.size(), stream_.end(), xmlCommentEnd.begin(), xmlCommentEnd.end());
+            auto it = std::search(pos_ + xmlCommentBegin_.size(), stream_.end(), xmlCommentEnd_.begin(), xmlCommentEnd_.end());
             if (it != stream_.end())
             {
-                pos = it + xmlCommentEnd.size();
-                return nextToken();
+                pos_ = it + xmlCommentEnd_.size();
+                return getNextToken(); //throw XmlParsingError
             }
         }
 
-        for (auto it = tokens.begin(); it != tokens.end(); ++it)
+        for (auto it = tokens_.begin(); it != tokens_.end(); ++it)
             if (startsWith(it->first))
             {
-                pos += it->first.size();
+                pos_ += it->first.size();
                 return it->second;
             }
 
-        auto nameEnd = std::find_if(pos, stream_.end(), [](char c)
+        const auto itNameEnd = std::find_if(pos_, stream_.end(), [](char c)
         {
             return c == '<'  ||
                    c == '>'  ||
                    c == '='  ||
                    c == '/'  ||
                    c == '\'' ||
-                   c == '\"' ||
-                   zen::isWhiteSpace(c);
+                   c == '"'  ||
+                   isWhiteSpace(c);
         });
 
-        if (nameEnd != pos)
+        if (itNameEnd != pos_)
         {
-            std::string name(&*pos, nameEnd - pos);
-            pos = nameEnd;
+            std::string name(pos_, itNameEnd);
+            pos_ = itNameEnd;
             return denormalize(name);
         }
 
@@ -366,34 +363,34 @@ public:
 
     std::string extractElementValue()
     {
-        auto it = std::find_if(pos, stream_.end(), [](char c)
+        auto it = std::find_if(pos_, stream_.end(), [](char c)
         {
             return c == '<'  ||
                    c == '>';
         });
-        std::string output(pos, it);
-        pos = it;
+        std::string output(pos_, it);
+        pos_ = it;
         return denormalize(output);
     }
 
     std::string extractAttributeValue()
     {
-        auto it = std::find_if(pos, stream_.end(), [](char c)
+        auto it = std::find_if(pos_, stream_.end(), [](char c)
         {
             return c == '<'  ||
                    c == '>'  ||
                    c == '\'' ||
-                   c == '\"';
+                   c == '"';
         });
-        std::string output(pos, it);
-        pos = it;
+        std::string output(pos_, it);
+        pos_ = it;
         return denormalize(output);
     }
 
     size_t posRow() const //current row beginning with 0
     {
-        const size_t crSum = std::count(stream_.begin(), pos, '\r'); //carriage returns
-        const size_t nlSum = std::count(stream_.begin(), pos, '\n'); //new lines
+        const size_t crSum = std::count(stream_.begin(), pos_, '\r'); //carriage returns
+        const size_t nlSum = std::count(stream_.begin(), pos_, '\n'); //new lines
         assert(crSum == 0 || nlSum == 0 || crSum == nlSum);
         return std::max(crSum, nlSum); //be compatible with Linux/Mac/Win
     }
@@ -401,13 +398,13 @@ public:
     size_t posCol() const //current col beginning with 0
     {
         //seek beginning of line
-        for (auto it = pos; it != stream_.begin(); )
+        for (auto it = pos_; it != stream_.begin(); )
         {
             --it;
             if (*it == '\r' || *it == '\n')
-                return pos - it - 1;
+                return pos_ - it - 1;
         }
-        return pos - stream_.begin();
+        return pos_ - stream_.begin();
     }
 
 private:
@@ -416,13 +413,11 @@ private:
 
     bool startsWith(const std::string& prefix) const
     {
-        if (stream_.end() - pos < static_cast<ptrdiff_t>(prefix.size()))
-            return false;
-        return std::equal(prefix.begin(), prefix.end(), pos);
+        return zen::startsWith(StringRef<const char>(pos_, stream_.end()), prefix);
     }
 
     using TokenList = std::vector<std::pair<std::string, Token::Type>>;
-    const TokenList tokens
+    const TokenList tokens_
     {
         { "<?xml", Token::TK_DECL_BEGIN    },
         { "?>",    Token::TK_DECL_END      },
@@ -435,11 +430,11 @@ private:
         { "\'",    Token::TK_QUOTE         },
     };
 
-    const std::string xmlCommentBegin = "<!--";
-    const std::string xmlCommentEnd   = "-->";
+    const std::string xmlCommentBegin_ = "<!--";
+    const std::string xmlCommentEnd_   = "-->";
 
     const std::string stream_;
-    std::string::const_iterator pos;
+    std::string::const_iterator pos_;
 };
 
 
@@ -448,7 +443,7 @@ class XmlParser
 public:
     XmlParser(const std::string& stream) :
         scn_(stream),
-        tk_(scn_.nextToken()) {}
+        tk_(scn_.getNextToken()) {} //throw XmlParsingError
 
     XmlDoc parse() //throw XmlParsingError
     {
@@ -457,19 +452,19 @@ public:
         //declaration (optional)
         if (token().type == Token::TK_DECL_BEGIN)
         {
-            nextToken();
+            nextToken(); //throw XmlParsingError
 
             while (token().type == Token::TK_NAME)
             {
                 std::string attribName = token().name;
-                nextToken();
+                nextToken(); //throw XmlParsingError
 
-                consumeToken(Token::TK_EQUAL);
-                expectToken(Token::TK_QUOTE);
+                consumeToken(Token::TK_EQUAL); //throw XmlParsingError
+                expectToken (Token::TK_QUOTE); //
                 std::string attribValue = scn_.extractAttributeValue();
-                nextToken();
+                nextToken(); //throw XmlParsingError
 
-                consumeToken(Token::TK_QUOTE);
+                consumeToken(Token::TK_QUOTE); //throw XmlParsingError
 
                 if (attribName == "version")
                     doc.setVersion(attribValue);
@@ -478,7 +473,7 @@ public:
                 else if (attribName == "standalone")
                     doc.setStandalone(attribValue);
             }
-            consumeToken(Token::TK_DECL_END);
+            consumeToken(Token::TK_DECL_END); //throw XmlParsingError
         }
 
         XmlElement dummy;
@@ -488,7 +483,7 @@ public:
         if (itPair.first != itPair.second)
             doc.root().swapSubtree(*itPair.first);
 
-        expectToken(Token::TK_END);
+        expectToken(Token::TK_END); //throw XmlParsingError
         return doc;
     }
 
@@ -500,11 +495,11 @@ private:
     {
         while (token().type == Token::TK_LESS)
         {
-            nextToken();
+            nextToken(); //throw XmlParsingError
 
-            expectToken(Token::TK_NAME);
+            expectToken(Token::TK_NAME); //throw XmlParsingError
             std::string elementName = token().name;
-            nextToken();
+            nextToken(); //throw XmlParsingError
 
             XmlElement& newElement = parent.addChild(elementName);
 
@@ -512,28 +507,28 @@ private:
 
             if (token().type == Token::TK_SLASH_GREATER) //empty element
             {
-                nextToken();
+                nextToken(); //throw XmlParsingError
                 continue;
             }
 
-            expectToken(Token::TK_GREATER);
+            expectToken(Token::TK_GREATER); //throw XmlParsingError
             std::string elementValue = scn_.extractElementValue();
-            nextToken();
+            nextToken(); //throw XmlParsingError
 
             //no support for mixed-mode content
-            if (token().type == Token::TK_LESS) //structured element
+            if (token().type == Token::TK_LESS) //structure-element
                 parseChildElements(newElement);
-            else //value element
+            else                                //value-element
                 newElement.setValue(elementValue);
 
-            consumeToken(Token::TK_LESS_SLASH);
+            consumeToken(Token::TK_LESS_SLASH); //throw XmlParsingError
 
-            if (token().type != Token::TK_NAME ||
-                elementName != token().name)
+            expectToken(Token::TK_NAME); //throw XmlParsingError
+            if (token().name != elementName)
                 throw XmlParsingError(scn_.posRow(), scn_.posCol());
-            nextToken();
+            nextToken(); //throw XmlParsingError
 
-            consumeToken(Token::TK_GREATER);
+            consumeToken(Token::TK_GREATER); //throw XmlParsingError
         }
     }
 
@@ -542,26 +537,21 @@ private:
         while (token().type == Token::TK_NAME)
         {
             std::string attribName = token().name;
-            nextToken();
+            nextToken(); //throw XmlParsingError
 
-            consumeToken(Token::TK_EQUAL);
-            expectToken(Token::TK_QUOTE);
+            consumeToken(Token::TK_EQUAL); //throw XmlParsingError
+            expectToken (Token::TK_QUOTE); //
             std::string attribValue = scn_.extractAttributeValue();
-            nextToken();
+            nextToken(); //throw XmlParsingError
 
-            consumeToken(Token::TK_QUOTE);
+            consumeToken(Token::TK_QUOTE); //throw XmlParsingError
             element.setAttribute(attribName, attribValue);
         }
     }
 
     const Token& token() const { return tk_; }
-    void nextToken() { tk_ = scn_.nextToken(); }
 
-    void consumeToken(Token::Type t) //throw XmlParsingError
-    {
-        expectToken(t); //throw XmlParsingError
-        nextToken();
-    }
+    void nextToken() { tk_ = scn_.getNextToken(); } //throw XmlParsingError
 
     void expectToken(Token::Type t) //throw XmlParsingError
     {
@@ -569,15 +559,21 @@ private:
             throw XmlParsingError(scn_.posRow(), scn_.posCol());
     }
 
+    void consumeToken(Token::Type t) //throw XmlParsingError
+    {
+        expectToken(t); //throw XmlParsingError
+        nextToken();    //
+    }
+
     Scanner scn_;
     Token tk_;
 };
 }
 
 inline
-XmlDoc parse(const std::string& stream) //throw XmlParsingError
+XmlDoc parseXml(const std::string& stream) //throw XmlParsingError
 {
-    return impl::XmlParser(stream).parse();  //throw XmlParsingError
+    return xml_impl::XmlParser(stream).parse(); //throw XmlParsingError
 }
 }
 
diff --git a/zenXml/zenxml/xml.h b/zenXml/zenxml/xml.h
index 9510645a..5eddc462 100755
--- a/zenXml/zenxml/xml.h
+++ b/zenXml/zenxml/xml.h
@@ -1,4 +1,4 @@
-// *****************************************************************************
+// *****************************************************************************
 // * This file is part of the FreeFileSync project. It is distributed under    *
 // * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0          *
 // * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
@@ -7,10 +7,444 @@
 #ifndef XML_H_349578228034572457454554
 #define XML_H_349578228034572457454554
 
-#include "bind.h"
+#include <set>
+#include <zen/file_io.h>
+#include <zen/file_access.h>
+#include "cvrt_struc.h"
+#include "parser.h"
 
 
 /// The zen::Xml namespace
-namespace zen {}
+namespace zen
+{
+/**
+\file
+\brief Save and load byte streams from files
+*/
+
+///Load XML document from a file
+/**
+Load and parse XML byte stream. Quick-exit if (potentially large) input file is not an XML.
+
+\param filePath Input file path
+\returns The loaded XML document
+\throw FileError
+*/
+namespace
+{
+XmlDoc loadXml(const Zstring& filePath) //throw FileError
+{
+    FileInput fileIn(filePath, nullptr /*notifyUnbufferedIO*/); //throw FileError, ErrorFileLocked
+    const size_t blockSize = fileIn.getBlockSize();
+    const std::string xmlPrefix = "<?xml version=";
+    bool xmlPrefixChecked = false;
+
+    std::string buffer;
+    for (;;)
+    {
+        buffer.resize(buffer.size() + blockSize);
+        const size_t bytesRead = fileIn.read(&*(buffer.end() - blockSize), blockSize); //throw FileError, ErrorFileLocked, (X); return "bytesToRead" bytes unless end of stream!
+        buffer.resize(buffer.size() - blockSize + bytesRead); //caveat: unsigned arithmetics
+
+        //quick test whether input is an XML: avoid loading large binary files up front!
+        if (!xmlPrefixChecked && buffer.size() >= xmlPrefix.size() + strLength(BYTE_ORDER_MARK_UTF8))
+        {
+            xmlPrefixChecked = true;
+            if (!startsWith(buffer, xmlPrefix) &&
+                !startsWith(buffer, BYTE_ORDER_MARK_UTF8 + xmlPrefix)) //allow BOM!
+                throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
+        }
+
+        if (bytesRead < blockSize) //end of file
+            break;
+    }
+
+    try
+    {
+        return parseXml(buffer); //throw XmlParsingError
+    }
+    catch (const XmlParsingError& e)
+    {
+        throw FileError(
+            replaceCpy(replaceCpy(replaceCpy(_("Error parsing file %x, row %y, column %z."),
+                                             L"%x", fmtPath(filePath)),
+                                  L"%y", numberTo<std::wstring>(e.row + 1)),
+                       L"%z", numberTo<std::wstring>(e.col + 1)));
+    }
+}
+}
+
+
+///Save XML document to a file
+/**
+Serialize XML to byte stream and save to file.
+
+\param doc The XML document to save
+\param filePath Output file path
+\throw FileError
+*/
+inline
+void saveXml(const XmlDoc& doc, const Zstring& filePath) //throw FileError
+{
+    const std::string stream = serializeXml(doc); //noexcept
+
+    try //only update XML file if there are changes
+    {
+        if (getFileSize(filePath) == stream.size()) //throw FileError
+            if (loadBinContainer<std::string>(filePath, nullptr /*notifyUnbufferedIO*/) == stream) //throw FileError
+                return;
+    }
+    catch (FileError&) {}
+
+    saveBinContainer(filePath, stream, nullptr /*notifyUnbufferedIO*/); //throw FileError
+}
+
+
+///Proxy class to conveniently convert user data into XML structure
+class XmlOut
+{
+public:
+    ///Construct an output proxy for an XML document
+    /**
+      \code
+        zen::XmlDoc doc;
+
+        zen::XmlOut out(doc);
+        out["elem1"]( 1); //
+        out["elem2"]( 2); //write data into XML elements
+        out["elem3"](-3); //
+
+        saveXml(doc, "out.xml"); //throw FileError
+      \endcode
+      Output:
+      \verbatim
+      <?xml version="1.0" encoding="utf-8"?>
+      <Root>
+          <elem1>1</elem1>
+          <elem2>2</elem2>
+          <elem3>-3</elem3>
+      </Root>
+      \endverbatim
+    */
+    XmlOut(XmlDoc& doc) : ref_(&doc.root()) {}
+    ///Construct an output proxy for a single XML element
+    /**
+      \sa XmlOut(XmlDoc& doc)
+    */
+    XmlOut(XmlElement& element) : ref_(&element) {}
+
+    ///Retrieve a handle to an XML child element for writing
+    /**
+    The child element will be created if it is not yet existing.
+    \tparam String Arbitrary string-like type: e.g. std::string, wchar_t*, char[], wchar_t, wxString, MyStringClass, ...
+    \param name The name of the child element
+    */
+    template <class String>
+    XmlOut operator[](const String& name) const
+    {
+        const std::string utf8name = utfTo<std::string>(name);
+        XmlElement* child = ref_->getChild(utf8name);
+        return child ? *child : ref_->addChild(utf8name);
+    }
+
+    ///Write user data to the underlying XML element
+    /**
+    This conversion requires a specialization of zen::writeText() or zen::writeStruc() for type T.
+    \tparam T User type that is converted into an XML element value.
+    */
+    template <class T>
+    void operator()(const T& value) { writeStruc(value, *ref_); }
+
+    ///Write user data to an XML attribute
+    /**
+    This conversion requires a specialization of zen::writeText() for type T.
+      \code
+        zen::XmlDoc doc;
+
+        zen::XmlOut out(doc);
+        out["elem"].attribute("attr1",  1); //
+        out["elem"].attribute("attr2",  2); //write data into XML attributes
+        out["elem"].attribute("attr3", -3); //
+
+        saveXml(doc, "out.xml"); //throw FileError
+      \endcode
+      Output:
+      \verbatim
+      <?xml version="1.0" encoding="utf-8"?>
+      <Root>
+          <elem attr1="1" attr2="2" attr3="-3"/>
+      </Root>
+      \endverbatim
+
+    \tparam String Arbitrary string-like type: e.g. std::string, wchar_t*, char[], wchar_t, wxString, MyStringClass, ...
+    \tparam T String-convertible user data type: e.g. any string-like type, all built-in arithmetic numbers
+    \sa XmlElement::setAttribute()
+    */
+    template <class String, class T>
+    void attribute(const String& name, const T& value) { ref_->setAttribute(name, value); }
+
+    ///Return a reference to the underlying Xml element
+    XmlElement& ref() { return *ref_; }
+
+private:
+    XmlElement* ref_; //always bound!
+};
+
+
+///Proxy class to conveniently convert XML structure to user data
+class XmlIn
+{
+    class ErrorLog;
+
+public:
+    ///Construct an input proxy for an XML document
+    /**
+      \code
+        zen::XmlDoc doc;
+          ... //load document
+        zen::XmlIn in(doc);
+        in["elem1"](value1); //
+        in["elem2"](value2); //read data from XML elements into variables "value1", "value2", "value3"
+        in["elem3"](value3); //
+      \endcode
+    */
+    XmlIn(const XmlDoc& doc) { refList_.push_back(&doc.root()); }
+    ///Construct an input proxy for a single XML element, may be nullptr
+    /**
+      \sa XmlIn(const XmlDoc& doc)
+    */
+    XmlIn(const XmlElement* element) { refList_.push_back(element); }
+    ///Construct an input proxy for a single XML element
+    /**
+      \sa XmlIn(const XmlDoc& doc)
+    */
+    XmlIn(const XmlElement& element) { refList_.push_back(&element); }
+
+    ///Retrieve a handle to an XML child element for reading
+    /**
+    It is \b not an error if the child element does not exist, but only later if a conversion to user data is attempted.
+    \tparam String Arbitrary string-like type: e.g. std::string, wchar_t*, char[], wchar_t, wxString, MyStringClass, ...
+    \param name The name of the child element
+    */
+    template <class String>
+    XmlIn operator[](const String& name) const
+    {
+        std::vector<const XmlElement*> childList;
+
+        if (refIndex_ < refList_.size())
+        {
+            auto iterPair = refList_[refIndex_]->getChildren(name);
+            std::for_each(iterPair.first, iterPair.second,
+            [&](const XmlElement& child) { childList.push_back(&child); });
+        }
+
+        return XmlIn(childList, childList.empty() ? getChildNameFormatted(name) : std::string(), log_);
+    }
+
+    ///Refer to next sibling element with the same name
+    /**
+    <b>Example:</b> Loop over all XML child elements named "Item"
+    \verbatim
+    <?xml version="1.0" encoding="utf-8"?>
+    <Root>
+        <Item>1</Item>
+        <Item>3</Item>
+        <Item>5</Item>
+    </Root>
+    \endverbatim
+
+    \code
+    zen::XmlIn in(doc);
+    ...
+    for (zen::XmlIn child = in["Item"]; child; child.next())
+    {
+        ...
+    }
+    \endcode
+    */
+    void next() { ++refIndex_; }
+
+    ///Read user data from the underlying XML element
+    /**
+    This conversion requires a specialization of zen::readText() or zen::readStruc() for type T.
+    \tparam T User type that receives the data
+    \return "true" if data was read successfully
+    */
+    template <class T>
+    bool operator()(T& value) const
+    {
+        if (refIndex_ < refList_.size())
+        {
+            bool success = readStruc(*refList_[refIndex_], value);
+            if (!success)
+                log_->notifyConversionError(getNameFormatted());
+            return success;
+        }
+        else
+        {
+            log_->notifyMissingElement(getNameFormatted());
+            return false;
+        }
+    }
+
+    ///Read user data from an XML attribute
+    /**
+    This conversion requires a specialization of zen::readText() for type T.
+
+    \code
+        zen::XmlDoc doc;
+          ... //load document
+        zen::XmlIn in(doc);
+        in["elem"].attribute("attr1", value1); //
+        in["elem"].attribute("attr2", value2); //read data from XML attributes into variables "value1", "value2", "value3"
+        in["elem"].attribute("attr3", value3); //
+    \endcode
+
+    \tparam String Arbitrary string-like type: e.g. std::string, wchar_t*, char[], wchar_t, wxString, MyStringClass, ...
+    \tparam T String-convertible user data type: e.g. any string-like type, all built-in arithmetic numbers
+    \returns "true" if the attribute was found and the conversion to the output value was successful.
+    \sa XmlElement::getAttribute()
+    */
+    template <class String, class T>
+    bool attribute(const String& name, T& value) const
+    {
+        if (refIndex_ < refList_.size())
+        {
+            bool success = refList_[refIndex_]->getAttribute(name, value);
+            if (!success)
+                log_->notifyMissingAttribute(getNameFormatted(), utfTo<std::string>(name));
+            return success;
+        }
+        else
+        {
+            log_->notifyMissingElement(getNameFormatted());
+            return false;
+        }
+    }
+
+    ///Return a pointer to the underlying Xml element, may be nullptr
+    const XmlElement* get() const { return refIndex_ < refList_.size() ? refList_[refIndex_] : nullptr; }
+
+    ///Test whether the underlying XML element exists
+    /**
+      \code
+         XmlIn in(doc);
+         XmlIn child = in["elem1"];
+         if (child)
+           ...
+      \endcode
+      Use member pointer as implicit conversion to bool (C++ Templates - Vandevoorde/Josuttis; chapter 20)
+    */
+    explicit operator bool() const { return get() != nullptr; }
+
+    ///Notifies errors while mapping the XML to user data
+    /**
+    Error logging is shared by each hiearchy of XmlIn proxy instances that are created from each other. Consequently it doesn't matter which instance you query for errors:
+      \code
+        XmlIn in(doc);
+        XmlIn inItem = in["item1"];
+
+        int value = 0;
+        inItem(value); //let's assume this conversion failed
+
+        assert(in.haveErrors() == inItem.haveErrors());
+        assert(in.getErrorsAs<std::string>() == inItem.getErrorsAs<std::string>());
+      \endcode
+
+      Note that error logging is \b NOT global, but owned by all instances of a hierarchy of XmlIn proxies.
+      Therefore it's safe to use unrelated XmlIn proxies in multiple threads.
+      \n\n
+      However be aware that the chain of connected proxy instances will be broken once you call XmlIn::get() to retrieve the underlying pointer.
+      Errors that occur when working with this pointer are not logged by the original set of related instances.
+    */
+    bool haveErrors() const { return !log_->elementList().empty(); }
+
+    ///Get a list of XML element and attribute names which failed to convert to user data.
+    /**
+      \tparam String Arbitrary string class: e.g. std::string, std::wstring, wxString, MyStringClass, ...
+      \returns A list of XML element and attribute names, empty list if no errors occured.
+    */
+    template <class String>
+    std::vector<String> getErrorsAs() const
+    {
+        std::vector<String> output;
+        const auto& elements = log_->elementList();
+        std::transform(elements.begin(), elements.end(), std::back_inserter(output), [](const std::string& str) { return utfTo<String>(str); });
+        return output;
+    }
+
+private:
+    XmlIn(const std::vector<const XmlElement*>& siblingList, const std::string& elementNameFmt, const std::shared_ptr<ErrorLog>& sharedlog) :
+        refList_(siblingList), formattedName_(elementNameFmt), log_(sharedlog)
+    { assert((!siblingList.empty() && elementNameFmt.empty()) || (siblingList.empty() && !elementNameFmt.empty())); }
+
+    static std::string getNameFormatted(const XmlElement& elem) //"<Root> <Level1> <Level2>"
+    {
+        return (elem.parent() ? getNameFormatted(*elem.parent()) + " " : std::string()) + "<" + elem.getNameAs<std::string>() + ">";
+    }
+
+    std::string getNameFormatted() const
+    {
+        if (refIndex_ < refList_.size())
+        {
+            assert(formattedName_.empty());
+            return getNameFormatted(*refList_[refIndex_]);
+        }
+        else
+            return formattedName_;
+    }
+
+    std::string getChildNameFormatted(const std::string& childName) const
+    {
+        std::string parentName = getNameFormatted();
+        return (parentName.empty() ? std::string() : (parentName + " ")) + "<" + childName + ">";
+    }
+
+    class ErrorLog
+    {
+    public:
+        void notifyConversionError (const std::string& displayName)  { insert(displayName); }
+        void notifyMissingElement  (const std::string& displayName)  { insert(displayName); }
+        void notifyMissingAttribute(const std::string& displayName, const std::string& attribName) { insert(displayName + " @" + attribName); }
+
+        const std::vector<std::string>& elementList() const { return failedElements; }
+
+    private:
+        void insert(const std::string& newVal)
+        {
+            if (usedElements.insert(newVal).second)
+                failedElements.push_back(newVal);
+        }
+
+        std::vector<std::string> failedElements; //unique list of failed elements
+        std::set<std::string>    usedElements;
+    };
+
+    std::vector<const XmlElement*> refList_; //all sibling elements with same name (all pointers bound!)
+    size_t refIndex_ = 0;                    //this sibling's index in refList_
+    std::string formattedName_;              //contains full and formatted element name if (and only if) refList_ is empty
+    std::shared_ptr<ErrorLog> log_{ std::make_shared<ErrorLog>() }; //always bound
+};
+
+
+///Check XML input proxy for errors and map to FileError exception
+/**
+\param xmlInput XML input proxy
+\param filePath Input file path
+\throw FileError
+*/
+inline
+void checkXmlMappingErrors(const XmlIn& xmlInput, const Zstring& filePath) //throw FileError
+{
+    if (xmlInput.haveErrors())
+    {
+        std::wstring msg = _("The following XML elements could not be read:") + L"\n";
+        for (const std::wstring& elem : xmlInput.getErrorsAs<std::wstring>())
+            msg += L"\n" + elem;
+
+        throw FileError(replaceCpy(_("Configuration file %x is incomplete. The missing elements will be set to their default values."), L"%x", fmtPath(filePath)) + L"\n\n" + msg);
+    }
+}
+}
 
 #endif //XML_H_349578228034572457454554