Merge branch 'b11.24' into 'master'11.24

add upstream 11.24

See merge request opensource-tracking/FreeFileSync!47

79 files changed, 1715 insertions, 1335 deletions

diff --git a/Changelog.txt b/Changelog.txt
index 5a53352c..ee265eee 100644
--- a/Changelog.txt
+++ b/Changelog.txt
@@ -1,3 +1,20 @@
+FreeFileSync 11.25
+------------------
+
+
+FreeFileSync 11.24 [2022-08-28]
+-------------------------------
+Enhanced filter syntax to match files only (append ':')
+Fixed "Some files will be synchronized as part of multiple base folders": no more false-positives
+Detect full path filter items and convert to relative path 
+Auto-detect FTP server character encoding (UTF8 or ANSI)
+Cancel grid selection via Escape key or second mouse button
+Apply conflict preview limit accross all folder pairs
+Require config type and file extension to match
+Fixed view filter panel vertical layout
+Strict validation of UTF encoding
+
+
 FreeFileSync 11.23 [2022-07-23]
 -------------------------------
 Format local file times with no limits on time span
diff --git a/FreeFileSync/Build/Resources/Icons.zip b/FreeFileSync/Build/Resources/Icons.zip
index c7a5e698..7de873b1 100644
--- a/FreeFileSync/Build/Resources/Icons.zip
+++ b/FreeFileSync/Build/Resources/Icons.zip
diff --git a/FreeFileSync/Build/Resources/Languages.zip b/FreeFileSync/Build/Resources/Languages.zip
index 8f6c9f21..ec222bbc 100644
--- a/FreeFileSync/Build/Resources/Languages.zip
+++ b/FreeFileSync/Build/Resources/Languages.zip
diff --git a/FreeFileSync/Source/Makefile b/FreeFileSync/Source/Makefile
index 69cf2536..eb6a6dbe 100644
--- a/FreeFileSync/Source/Makefile
+++ b/FreeFileSync/Source/Makefile
@@ -1,30 +1,31 @@
+CXX ?= g++
 exeName = FreeFileSync_$(shell arch)
 
-cxxFlags = -std=c++2b -pipe -DWXINTL_NO_GETTEXT_MACRO -I../.. -I../../zenXml -include "zen/i18n.h" -include "zen/warn_static.h" \
+CXXFLAGS += -std=c++2b -pipe -DWXINTL_NO_GETTEXT_MACRO -I../.. -I../../zenXml -include "zen/i18n.h" -include "zen/warn_static.h" \
            -Wall -Wfatal-errors -Wmissing-include-dirs -Wswitch-enum -Wcast-align -Wnon-virtual-dtor -Wno-unused-function -Wshadow -Wno-maybe-uninitialized \
            -O3 -DNDEBUG `wx-config --cxxflags --debug=no` -pthread
 
-linkFlags = -s -no-pie `wx-config --libs std, aui, richtext --debug=no` -pthread
+LDFLAGS += -s -no-pie `wx-config --libs std, aui, richtext --debug=no` -pthread
 
 
-cxxFlags  += `pkg-config --cflags openssl`
-linkFlags += `pkg-config --libs   openssl`
+CXXFLAGS  += `pkg-config --cflags openssl`
+LDFLAGS += `pkg-config --libs   openssl`
 
-cxxFlags  += `pkg-config --cflags libcurl`
-linkFlags += `pkg-config --libs   libcurl`
+CXXFLAGS  += `pkg-config --cflags libcurl`
+LDFLAGS += `pkg-config --libs   libcurl`
 
-cxxFlags  += `pkg-config --cflags libssh2`
-linkFlags += `pkg-config --libs   libssh2`
+CXXFLAGS  += `pkg-config --cflags libssh2`
+LDFLAGS += `pkg-config --libs   libssh2`
 
-cxxFlags  += `pkg-config --cflags gtk+-2.0`
+CXXFLAGS  += `pkg-config --cflags gtk+-2.0`
 #treat as system headers so that warnings are hidden:
-cxxFlags  += -isystem/usr/include/gtk-2.0
+CXXFLAGS  += -isystem/usr/include/gtk-2.0
 
 #support for SELinux (optional)
 SELINUX_EXISTING=$(shell pkg-config --exists libselinux && echo YES)
 ifeq ($(SELINUX_EXISTING),YES)
-cxxFlags  += `pkg-config --cflags libselinux` -DHAVE_SELINUX
-linkFlags += `pkg-config --libs libselinux`
+CXXFLAGS  += `pkg-config --cflags libselinux` -DHAVE_SELINUX
+LDFLAGS += `pkg-config --libs libselinux`
 endif
 
 cppFiles=
@@ -116,11 +117,11 @@ all: ../Build/Bin/$(exeName)
 
 ../Build/Bin/$(exeName): $(objFiles)
 	mkdir -p $(dir $@)
-	g++ -o $@ $^ $(linkFlags)
+	$(CXX) -o $@ $^ $(LDFLAGS)
 
 $(tmpPath)/ffs/src/%.o : %
 	mkdir -p $(dir $@)
-	g++ $(cxxFlags) -c $< -o $@
+	$(CXX) $(CXXFLAGS) -c $< -o $@
 
 clean:
 	rm -rf $(tmpPath)
diff --git a/FreeFileSync/Source/RealTimeSync/Makefile b/FreeFileSync/Source/RealTimeSync/Makefile
index 26d370c0..661b6b78 100644
--- a/FreeFileSync/Source/RealTimeSync/Makefile
+++ b/FreeFileSync/Source/RealTimeSync/Makefile
@@ -1,15 +1,16 @@
+CXX ?= g++
 exeName = RealTimeSync_$(shell arch)
 
-cxxFlags = -std=c++2b -pipe -DWXINTL_NO_GETTEXT_MACRO -I../../.. -I../../../zenXml -include "zen/i18n.h" -include "zen/warn_static.h" \
+CXXFLAGS += -std=c++2b -pipe -DWXINTL_NO_GETTEXT_MACRO -I../../.. -I../../../zenXml -include "zen/i18n.h" -include "zen/warn_static.h" \
            -Wall -Wfatal-errors -Wmissing-include-dirs -Wswitch-enum -Wcast-align -Wnon-virtual-dtor -Wno-unused-function -Wshadow -Wno-maybe-uninitialized \
            -O3 -DNDEBUG `wx-config --cxxflags --debug=no` -pthread
 
-linkFlags = -s -no-pie `wx-config --libs std, aui, richtext --debug=no` -pthread
+LDFLAGS += -s -no-pie `wx-config --libs std, aui, richtext --debug=no` -pthread
 
 #Gtk - support "no button border"
-cxxFlags  += `pkg-config --cflags gtk+-2.0`
+CXXFLAGS  += `pkg-config --cflags gtk+-2.0`
 #treat as system headers so that warnings are hidden:
-cxxFlags  += -isystem/usr/include/gtk-2.0
+CXXFLAGS  += -isystem/usr/include/gtk-2.0
 
 cppFiles=
 cppFiles+=application.cpp
@@ -55,11 +56,11 @@ all: ../../Build/Bin/$(exeName)
 
 ../../Build/Bin/$(exeName): $(objFiles)
 	mkdir -p $(dir $@)
-	g++ -o $@ $^ $(linkFlags)
+	$(CXX) -o $@ $^ $(LDFLAGS)
 
 $(tmpPath)/ffs/src/rts/%.o : %
 	mkdir -p $(dir $@)
-	g++ $(cxxFlags) -c $< -o $@
+	$(CXX) $(CXXFLAGS) -c $< -o $@
 
 clean:
 	rm -rf $(tmpPath)
diff --git a/FreeFileSync/Source/RealTimeSync/application.cpp b/FreeFileSync/Source/RealTimeSync/application.cpp
index d7924d32..8928ab5d 100644
--- a/FreeFileSync/Source/RealTimeSync/application.cpp
+++ b/FreeFileSync/Source/RealTimeSync/application.cpp
@@ -93,7 +93,7 @@ bool Application::OnInit()
         ZEN_ON_SCOPE_EXIT(if (error) ::g_error_free(error));
 
         ::gtk_css_provider_load_from_path(provider, //GtkCssProvider* css_provider,
-                                           appendPath(fff::getResourceDirPath(), fileName).c_str(), //const gchar* path,
+                                          appendPath(fff::getResourceDirPath(), fileName).c_str(), //const gchar* path,
                                           &error); //GError** error
         if (error)
             throw SysError(formatGlibError("gtk_css_provider_load_from_path", error));
@@ -173,28 +173,21 @@ void Application::onEnterEventLoop(wxEvent& event)
     std::vector<Zstring> commandArgs;
     for (int i = 1; i < argc; ++i)
     {
-        Zstring filePath = getResolvedFilePath(utfTo<Zstring>(argv[i]));
-
-        if (!fileAvailable(filePath)) //be a little tolerant
-        {
-            if (fileAvailable(filePath + Zstr(".ffs_real")))
-                filePath += Zstr(".ffs_real");
-            else if (fileAvailable(filePath + Zstr(".ffs_batch")))
-                filePath += Zstr(".ffs_batch");
-            else
-            {
-                showNotificationDialog(nullptr, DialogInfoType::error, PopupDialogCfg().setMainInstructions(replaceCpy(_("Cannot find file %x."), L"%x", fmtPath(filePath))));
-                return;
-            }
-        }
+        const Zstring& filePath = getResolvedFilePath(utfTo<Zstring>(argv[i]));
+#if 0
+        if (!fileAvailable(filePath)) //...be a little tolerant
+            for (const Zchar* ext : {Zstr(".ffs_real"), Zstr(".ffs_batch")})
+                if (fileAvailable(filePath + ext))
+                    filePath += ext;
+#endif
         commandArgs.push_back(filePath);
     }
 
-    Zstring cfgFilename;
+    Zstring cfgFilePath;
     if (!commandArgs.empty())
-        cfgFilename = commandArgs[0];
+        cfgFilePath = commandArgs[0];
 
-    MainDialog::create(cfgFilename);
+    MainDialog::create(cfgFilePath);
 }
 
 
diff --git a/FreeFileSync/Source/RealTimeSync/config.cpp b/FreeFileSync/Source/RealTimeSync/config.cpp
index 53b76fac..ff5cf29f 100644
--- a/FreeFileSync/Source/RealTimeSync/config.cpp
+++ b/FreeFileSync/Source/RealTimeSync/config.cpp
@@ -37,29 +37,15 @@ bool readText(const std::string& input, wxLanguage& value)
 
 namespace
 {
-enum class RtsXmlType
-{
-    real,
-    batch,
-    global,
-    other
-};
-RtsXmlType getXmlTypeNoThrow(const XmlDoc& doc) //throw()
+std::string getConfigType(const XmlDoc& doc)
 {
     if (doc.root().getName() == "FreeFileSync")
     {
         std::string type;
         if (doc.root().getAttribute("XmlType", type))
-        {
-            if (type == "REAL")
-                return RtsXmlType::real;
-            else if (type == "BATCH")
-                return RtsXmlType::batch;
-            else if (type == "GLOBAL")
-                return RtsXmlType::global;
-        }
+            return type;
     }
-    return RtsXmlType::other;
+    return {};
 }
 
 
@@ -90,7 +76,7 @@ void rts::readConfig(const Zstring& filePath, XmlRealConfig& cfg, std::wstring&
 {
     XmlDoc doc = loadXml(filePath); //throw FileError
 
-    if (getXmlTypeNoThrow(doc) != RtsXmlType::real) //noexcept
+    if (getConfigType(doc) != "REAL")
         throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
 
     int formatVer = 0;
@@ -130,10 +116,8 @@ void rts::readRealOrBatchConfig(const Zstring& filePath, XmlRealConfig& cfg, std
     XmlDoc doc = loadXml(filePath); //throw FileError
     //quick exit if file is not an FFS XML
 
-    const RtsXmlType xmlType = ::getXmlTypeNoThrow(doc);
-
     //convert batch config to RealTimeSync config
-    if (xmlType == RtsXmlType::batch)
+    if (getConfigType(doc) == "BATCH")
     {
         XmlIn in(doc);
 
@@ -180,7 +164,7 @@ wxLanguage rts::getProgramLanguage() //throw FileError
         throw;
     }
 
-    if (getXmlTypeNoThrow(doc) != RtsXmlType::global) //noexcept
+    if (getConfigType(doc) != "GLOBAL")
         throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
 
     XmlIn in(doc);
diff --git a/FreeFileSync/Source/RealTimeSync/folder_selector2.cpp b/FreeFileSync/Source/RealTimeSync/folder_selector2.cpp
index 01767ae3..671ce606 100644
--- a/FreeFileSync/Source/RealTimeSync/folder_selector2.cpp
+++ b/FreeFileSync/Source/RealTimeSync/folder_selector2.cpp
@@ -133,9 +133,16 @@ void FolderSelector2::onSelectDir(wxCommandEvent& event)
     //IFileDialog requirements for default path: 1. accepts native paths only!!! 2. path must exist!
     Zstring defaultFolderPath;
     {
-        auto folderExistsTimed = [waitEndTime = std::chrono::steady_clock::now() + FOLDER_SELECTED_EXISTENCE_CHECK_TIME_MAX](const Zstring& folderPath)
+        auto folderAccessible = [waitEndTime = std::chrono::steady_clock::now() + FOLDER_SELECTED_EXISTENCE_CHECK_TIME_MAX](const Zstring& folderPath)
         {
-            auto ft = runAsync([folderPath] { return dirAvailable(folderPath); });
+            auto ft = runAsync([folderPath]
+            {
+                try
+                {
+                    return getItemType(folderPath) != ItemType::file; //throw FileError
+                }
+                catch (FileError&) { return false; }
+            });
 
             return ft.wait_until(waitEndTime) == std::future_status::ready && ft.get(); //potentially slow network access: wait 200ms at most
         };
@@ -145,7 +152,7 @@ void FolderSelector2::onSelectDir(wxCommandEvent& event)
 
             if (const Zstring folderPath = getResolvedFilePath(folderPathPhrase);
                 !folderPath.empty())
-                if (folderExistsTimed(folderPath))
+                if (folderAccessible(folderPath))
                     defaultFolderPath = folderPath;
         };
 
diff --git a/FreeFileSync/Source/RealTimeSync/main_dlg.cpp b/FreeFileSync/Source/RealTimeSync/main_dlg.cpp
index f6b9b337..d240dd0f 100644
--- a/FreeFileSync/Source/RealTimeSync/main_dlg.cpp
+++ b/FreeFileSync/Source/RealTimeSync/main_dlg.cpp
@@ -62,13 +62,13 @@ private:
 };
 
 
-void MainDialog::create(const Zstring& cfgFile)
+void MainDialog::create(const Zstring& cfgFilePath)
 {
-    /*MainDialog* frame = */ new MainDialog(cfgFile);
+    /*MainDialog* frame = */ new MainDialog(cfgFilePath);
 }
 
 
-MainDialog::MainDialog(const Zstring& cfgFileName) :
+MainDialog::MainDialog(const Zstring& cfgFilePath) :
     MainDlgGenerated(nullptr),
     lastRunConfigPath_(appendPath(fff::getConfigDirPath(), Zstr("LastRun.ffs_real")))
 {
@@ -102,7 +102,7 @@ MainDialog::MainDialog(const Zstring& cfgFileName) :
     //--------------------------- load config values ------------------------------------
     XmlRealConfig newConfig;
 
-    Zstring currentConfigFile = cfgFileName;
+    Zstring currentConfigFile = cfgFilePath;
     if (currentConfigFile.empty())
         try
         {
@@ -128,7 +128,7 @@ MainDialog::MainDialog(const Zstring& cfgFileName) :
             showNotificationDialog(this, DialogInfoType::error, PopupDialogCfg().setDetailInstructions(e.toString()));
         }
 
-    const bool startWatchingImmediately = loadCfgSuccess && !cfgFileName.empty();
+    const bool startWatchingImmediately = loadCfgSuccess && !cfgFilePath.empty();
 
     setConfiguration(newConfig);
     setLastUsedConfig(currentConfigFile);
@@ -253,7 +253,10 @@ void MainDialog::onConfigSave(wxCommandEvent& event)
                               wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
     if (fileSelector.ShowModal() != wxID_OK)
         return;
-    const Zstring targetFilePath = utfTo<Zstring>(fileSelector.GetPath());
+
+    Zstring targetFilePath = utfTo<Zstring>(fileSelector.GetPath());
+    if (!endsWithAsciiNoCase(targetFilePath, Zstr(".ffs_real"))) //no weird shit!
+        targetFilePath += Zstr(".ffs_real");          //https://freefilesync.org/forum/viewtopic.php?t=9451#p34724
 
     const XmlRealConfig currentCfg = getConfiguration();
     try
diff --git a/FreeFileSync/Source/RealTimeSync/main_dlg.h b/FreeFileSync/Source/RealTimeSync/main_dlg.h
index f83c5440..76b1111f 100644
--- a/FreeFileSync/Source/RealTimeSync/main_dlg.h
+++ b/FreeFileSync/Source/RealTimeSync/main_dlg.h
@@ -26,10 +26,10 @@ class DirectoryPanel;
 class MainDialog: public MainDlgGenerated
 {
 public:
-    static void create(const Zstring& cfgFile);
+    static void create(const Zstring& cfgFilePath);
 
 private:
-    MainDialog(const Zstring& cfgFileName);
+    MainDialog(const Zstring& cfgFilePath);
     ~MainDialog();
 
     void onBeforeSystemShutdown(); //last chance to do something useful before killing the application!
diff --git a/FreeFileSync/Source/afs/abstract.h b/FreeFileSync/Source/afs/abstract.h
index 716e3bef..0aae8bc0 100644
--- a/FreeFileSync/Source/afs/abstract.h
+++ b/FreeFileSync/Source/afs/abstract.h
@@ -132,7 +132,7 @@ struct AbstractFileSystem //THREAD-SAFETY: "const" member functions must model t
 
     struct StreamAttributes
     {
-        time_t modTime; //number of seconds since Jan. 1st 1970 UTC
+        time_t modTime; //number of seconds since Jan. 1st 1970 GMT
         uint64_t fileSize;
         FingerPrint filePrint; //optional
     };
@@ -197,7 +197,7 @@ struct AbstractFileSystem //THREAD-SAFETY: "const" member functions must model t
     {
         Zstring itemName;
         uint64_t fileSize; //unit: bytes!
-        time_t modTime; //number of seconds since Jan. 1st 1970 UTC
+        time_t modTime; //number of seconds since Jan. 1st 1970 GMT
         FingerPrint filePrint; //optional; persistent + unique (relative to device) or 0!
         bool isFollowedSymlink;
     };
@@ -263,7 +263,7 @@ struct AbstractFileSystem //THREAD-SAFETY: "const" member functions must model t
     struct FileCopyResult
     {
         uint64_t fileSize = 0;
-        time_t modTime = 0; //number of seconds since Jan. 1st 1970 UTC
+        time_t modTime = 0; //number of seconds since Jan. 1st 1970 GMT
         FingerPrint sourceFilePrint = 0; //optional
         FingerPrint targetFilePrint = 0; //
         std::optional<zen::FileError> errorModTime; //failure to set modification time
diff --git a/FreeFileSync/Source/afs/ftp.cpp b/FreeFileSync/Source/afs/ftp.cpp
index 06add192..cd66c047 100644
--- a/FreeFileSync/Source/afs/ftp.cpp
+++ b/FreeFileSync/Source/afs/ftp.cpp
@@ -35,10 +35,12 @@ const int FTP_STREAM_BUFFER_SIZE = 512 * 1024; //unit: [byte]
 
 const Zchar ftpPrefix[] = Zstr("ftp:");
 
+
 enum class ServerEncoding
 {
+    unknown,
     utf8,
-    ansi
+    ansi,
 };
 
 
@@ -123,34 +125,6 @@ std::string utfToAnsiEncoding(const Zstring& str) //throw SysError
 }
 
 
-Zstring serverToUtfEncoding(const std::string& str, ServerEncoding enc) //throw SysError
-{
-    switch (enc)
-    {
-        case ServerEncoding::utf8:
-            return utfTo<Zstring>(str);
-        case ServerEncoding::ansi:
-            return ansiToUtfEncoding(str); //throw SysError
-    }
-    assert(false);
-    return {};
-}
-
-
-std::string utfToServerEncoding(const Zstring& str, ServerEncoding enc) //throw SysError
-{
-    switch (enc)
-    {
-        case ServerEncoding::utf8:
-            return utfTo<std::string>(str);
-        case ServerEncoding::ansi:
-            return utfToAnsiEncoding(str); //throw SysError
-    }
-    assert(false);
-    return {};
-}
-
-
 std::wstring getCurlDisplayPath(const FtpSessionId& sessionId, const AfsPath& afsPath)
 {
     Zstring displayPath = Zstring(ftpPrefix) + Zstr("//");
@@ -302,7 +276,7 @@ public:
                         const std::vector<CurlOption>& extraOptions, bool requiresUtf8) //throw SysError
     {
         if (requiresUtf8) //avoid endless recursion
-            ensureUtf8(); //throw SysError
+            requestUtf8(); //throw SysError
 
         if (!easyHandle_)
         {
@@ -605,8 +579,7 @@ public:
                                 else
                                 {
                                     const std::string homePathRaw = replaceCpy(std::string{itBegin, it}, "\"\"", '"');
-                                    const ServerEncoding enc = getServerEncoding(); //throw SysError
-                                    const Zstring homePathUtf = serverToUtfEncoding(homePathRaw, enc); //throw SysError
+                                    const Zstring homePathUtf = serverToUtfEncoding(homePathRaw); //throw SysError
                                     return sanitizeDeviceRelativePath(homePathUtf);
                                 }
                             }
@@ -627,13 +600,13 @@ public:
 
         //make sure our binary-enabled session is still there (== libcurl behaves as we expect)
         std::optional<curl_socket_t> currentSocket = getActiveSocket(); //throw SysError
-        if (!currentSocket)
-            throw SysError(L"Curl failed to cache FTP session."); //why is libcurl not caching the session???
-
-        binaryEnabledSocket_ = *currentSocket; //remember what we did
+        if (currentSocket)
+            binaryEnabledSocket_ = *currentSocket; //remember what we did
         //libcurl already buffers "conn->proto.ftpc.transfertype" but selfishly keeps it for itself!
         //=> pray libcurl doesn't internally set "TYPE A"!
         //=> this seems to be the only place where it does: https://github.com/curl/curl/issues/4342
+        else
+            throw SysError(L"Curl failed to cache FTP session."); //why is libcurl not caching the session???
     }
 
     //------------------------------------------------------------------------------------------------------------
@@ -642,8 +615,6 @@ public:
     bool supportsClnt() { return getFeatureSupport(&Features::clnt); } //
     bool supportsUtf8() { return getFeatureSupport(&Features::utf8); } //
 
-    ServerEncoding getServerEncoding() { return supportsUtf8() ? ServerEncoding::utf8 : ServerEncoding::ansi; } //throw SysError
-
     bool isHealthy() const
     {
         return std::chrono::steady_clock::now() - lastSuccessfulUseTime_ <= FTP_SESSION_MAX_IDLE_TIME;
@@ -653,12 +624,68 @@ public:
     {
         const Zstring serverPath = getServerRelPath(afsPath);
 
-        if (afsPath.value.empty()) //endless recursion caveat!! getServerEncoding() transitively depends on getServerPathInternal()
+        if (afsPath.value.empty()) //endless recursion caveat!! utfToServerEncoding() transitively depends on getServerPathInternal()
             return utfTo<std::string>(serverPath);
 
-        const ServerEncoding encoding = getServerEncoding(); //throw SysError
+        return utfToServerEncoding(serverPath); //throw SysError
+    }
+
+    Zstring serverToUtfEncoding(const std::string& str) //throw SysError
+    {
+        if (isAsciiString(str)) //fast path
+            return {str.begin(), str.end()};
+
+        switch (encoding_) //throw SysError
+        {
+            case ServerEncoding::unknown:
+                /* "UTF-8 encodings [2] contain enough internal structure that it is always, in practice, possible to determine whether a UTF-8 or raw encoding has been used"
+                    - https://www.rfc-editor.org/rfc/rfc3659#section-2.2
+                  "encoding rules make it very unlikely that a character sequence from a different character set will be mistaken for a UTF-8 encoded character sequence."
+                    - https://www.rfc-editor.org/rfc/rfc2640#section-2.2
+
+                  => auto-detect encoding even if FEAT does not advertize UTF8: https://freefilesync.org/forum/viewtopic.php?t=9564       */
+                encoding_ = supportsUtf8() || isValidUtf(str) ? ServerEncoding::utf8 : ServerEncoding::ansi;
+                return serverToUtfEncoding(str); //throw SysError
+
+            case ServerEncoding::utf8:
+                if (!isValidUtf(str))
+                    throw SysError(_("Invalid character encoding:") + L" [UTF-8] " + utfTo<std::wstring>(str));
 
-        return utfToServerEncoding(serverPath, encoding); //throw SysError
+                return utfTo<Zstring>(str);
+
+            case ServerEncoding::ansi:
+                return ansiToUtfEncoding(str); //throw SysError
+        }
+        assert(false);
+        return {};
+    }
+
+    std::string utfToServerEncoding(const Zstring& str) //throw SysError
+    {
+        if (isAsciiString(str)) //fast path
+            return {str.begin(), str.end()};
+        switch (encoding_) //throw SysError
+        {
+            case ServerEncoding::unknown:
+                if (!supportsUtf8())
+                    throw SysError(_("Failed to auto-detect character encoding:") + L' ' + utfTo<std::wstring>(str)); //might be ANSI or UTF8 with non-compliant server...
+
+                encoding_ = ServerEncoding::utf8;
+                return utfToServerEncoding(str); //throw SysError
+
+            case ServerEncoding::utf8:
+                //validate! we consider REPLACEMENT_CHAR as indication for server using ANSI encoding in serverToUtfEncoding()
+                if (!isValidUtf(str))
+                    throw SysError(_("Invalid character encoding:") + (sizeof(str[0]) == 1 ? L" [UTF-8] " : L" [UTF-16] ") + utfTo<std::wstring>(str));
+                static_assert(sizeof(str[0]) == 1 || sizeof(str[0]) == 2);
+
+                return utfTo<std::string>(str);
+
+            case ServerEncoding::ansi:
+                return utfToAnsiEncoding(str); //throw SysError
+        }
+        assert(false);
+        return {};
     }
 
 private:
@@ -693,36 +720,37 @@ private:
         return path;
     }
 
-    void ensureUtf8() //throw SysError
+    void requestUtf8() //throw SysError
     {
+        //Some RFC-2640-non-compliant servers require UTF8 to be explicitly enabled: https://wiki.filezilla-project.org/Character_Encoding#Conflicting_specification
+        //e.g. this one (Microsoft FTP Service): https://freefilesync.org/forum/viewtopic.php?t=4303
+
+        //check supportsUtf8()? no, let's *always* request UTF8, even if server does not set UTF8 in FEAT response! e.g. like https://freefilesync.org/forum/viewtopic.php?t=9564
+        //=> should not hurt + we rely on auto-encoding detection anyway; see serverToUtfEncoding()
+
         //"OPTS UTF8 ON" needs to be activated each time libcurl internally creates a new session
         //hopyfully libcurl will offer a better solution: https://github.com/curl/curl/issues/1457
 
-        //Some RFC-2640-non-compliant servers require UTF8 to be explicitly enabled: https://wiki.filezilla-project.org/Character_Encoding#Conflicting_specification
-        //e.g. this one (Microsoft FTP Service): https://freefilesync.org/forum/viewtopic.php?t=4303
-        if (supportsUtf8()) //throw SysError
-        {
-            //[!] supportsUtf8() is buffered! => FTP session might not yet exist (or was closed by libcurl after a failure)
-            if (std::optional<curl_socket_t> currentSocket = getActiveSocket()) //throw SysError
-                if (*currentSocket == utf8EnabledSocket_) //caveat: a non-UTF8-enabled session might already exist, e.g. from a previous call to supportsMlsd()
-                    return;
+        if (std::optional<curl_socket_t> currentSocket = getActiveSocket()) //throw SysError
+            if (*currentSocket == utf8RequestedSocket_) //caveat: a non-UTF8-enabled session might already exist, e.g. from a previous call to supportsMlsd()
+                return;
 
-            //some servers even require "CLNT" before accepting "OPTS UTF8 ON": https://social.msdn.microsoft.com/Forums/en-US/d602574f-8a69-4d69-b337-52b6081902cf/problem-with-ftpwebrequestopts-utf8-on-501-please-clnt-first
-            if (supportsClnt()) //throw SysError
-                runSingleFtpCommand("CLNT FreeFileSync", false /*requiresUtf8*/); //throw SysError
+        //some servers even require "CLNT" before accepting "OPTS UTF8 ON": https://social.msdn.microsoft.com/Forums/en-US/d602574f-8a69-4d69-b337-52b6081902cf/problem-with-ftpwebrequestopts-utf8-on-501-please-clnt-first
+        if (supportsClnt()) //throw SysError
+            runSingleFtpCommand("CLNT FreeFileSync", false /*requiresUtf8*/); //throw SysError
 
-            //"prefix the command with an asterisk to make libcurl continue even if the command fails"
-            //-> ignore if server does not know this legacy command (but report all *other* issues; else getActiveSocket() below won't return value and hide real error!)
-            //"If an RFC 2640 compliant client sends OPTS UTF-8 ON, it has to use UTF-8 regardless whether OPTS UTF-8 ON succeeds or not. "
-            runSingleFtpCommand("*OPTS UTF8 ON", false /*requiresUtf8*/); //throw SysError
+        //"prefix the command with an asterisk to make libcurl continue even if the command fails"
+        //-> ignore if server does not know this legacy command (but report all *other* issues; else getActiveSocket() below won't return value and hide real error!)
+        //"If an RFC 2640 compliant client sends OPTS UTF-8 ON, it has to use UTF-8 regardless whether OPTS UTF-8 ON succeeds or not. "
+        runSingleFtpCommand("*OPTS UTF8 ON", false /*requiresUtf8*/); //throw SysError
 
-            //make sure our unicode-enabled session is still there (== libcurl behaves as we expect)
-            std::optional<curl_socket_t> currentSocket = getActiveSocket(); //throw SysError
-            if (!currentSocket)
-                throw SysError(L"Curl failed to cache FTP session."); //why is libcurl not caching the session???
+        //make sure our Unicode-enabled session is still there (== libcurl behaves as we expect)
+        std::optional<curl_socket_t> currentSocket = getActiveSocket(); //throw SysError
+        if (currentSocket)
+            utf8RequestedSocket_ = *currentSocket; //remember what we did
+        else
+            throw SysError(L"Curl failed to cache FTP session."); //why is libcurl not caching the session???
 
-            utf8EnabledSocket_ = *currentSocket; //remember what we did
-        }
     }
 
     std::optional<curl_socket_t> getActiveSocket() //throw SysError
@@ -765,7 +793,7 @@ private:
             {
                 //*: ignore error if server does not support/allow FEAT
                 featureCache_ = parseFeatResponse(runSingleFtpCommand("*FEAT", false /*requiresUtf8*/)); //throw SysError
-                //used by ensureUtf8()! => requiresUtf8 = false!!!
+                //used by requestUtf8()! => requiresUtf8 = false!!!
 
                 sf->access([&](FeatureList& feat) { feat[sessionId_.server] = featureCache_; });
             }
@@ -822,9 +850,11 @@ private:
     const FtpSessionId sessionId_;
     CURL* easyHandle_ = nullptr;
 
-    curl_socket_t utf8EnabledSocket_ = 0;
+    curl_socket_t utf8RequestedSocket_ = 0;
     curl_socket_t binaryEnabledSocket_ = 0;
 
+    ServerEncoding encoding_ = ServerEncoding::unknown;
+
     std::optional<Features> featureCache_;
     std::optional<AfsPath> homePathCached_;
 
@@ -1098,11 +1128,10 @@ public:
 
                 session.perform(afsDirPath, true /*isDir*/, pathMethod, options, true /*requiresUtf8*/); //throw SysError
 
-                const ServerEncoding encoding = session.getServerEncoding(); //throw SysError
                 if (session.supportsMlsd()) //throw SysError
-                    output = parseMlsd(rawListing, encoding); //throw SysError
+                    output = parseMlsd(rawListing, session); //throw SysError
                 else
-                    output = parseUnknown(rawListing, encoding); //throw SysError
+                    output = parseUnknown(rawListing, session); //throw SysError
             });
         }
         catch (const SysError& e)
@@ -1116,12 +1145,12 @@ private:
     FtpDirectoryReader           (const FtpDirectoryReader&) = delete;
     FtpDirectoryReader& operator=(const FtpDirectoryReader&) = delete;
 
-    static std::vector<FtpItem> parseMlsd(const std::string& buf, ServerEncoding enc) //throw SysError
+    static std::vector<FtpItem> parseMlsd(const std::string& buf, FtpSession& session) //throw SysError
     {
         std::vector<FtpItem> output;
         for (const std::string& line : splitFtpResponse(buf))
         {
-            const FtpItem item = parseMlstLine(line, enc); //throw SysError
+            const FtpItem item = parseMlstLine(line, session); //throw SysError
             if (item.itemName != Zstr(".") &&
                 item.itemName != Zstr(".."))
                 output.push_back(item);
@@ -1129,7 +1158,7 @@ private:
         return output;
     }
 
-    static FtpItem parseMlstLine(const std::string& rawLine, ServerEncoding enc) //throw SysError
+    static FtpItem parseMlstLine(const std::string& rawLine, FtpSession& session) //throw SysError
     {
         /*  https://tools.ietf.org/html/rfc3659
             type=cdir;sizd=4096;modify=20170116230740;UNIX.mode=0755;UNIX.uid=874;UNIX.gid=869;unique=902g36e1c55; .
@@ -1148,7 +1177,7 @@ private:
                 throw SysError(L"Item name not available.");
 
             const std::string facts(itBegin, itBlank);
-            item.itemName = serverToUtfEncoding(std::string(itBlank + 1, rawLine.end()), enc); //throw SysError
+            item.itemName = session.serverToUtfEncoding(std::string(itBlank + 1, rawLine.end())); //throw SysError
 
             std::string typeFact;
             std::optional<uint64_t> fileSize;
@@ -1220,15 +1249,15 @@ private:
         }
     }
 
-    static std::vector<FtpItem> parseUnknown(const std::string& buf, ServerEncoding enc) //throw SysError
+    static std::vector<FtpItem> parseUnknown(const std::string& buf, FtpSession& session) //throw SysError
     {
         if (!buf.empty() && isDigit(buf[0])) //lame test to distinguish Unix/Dos formats as internally used by libcurl
-            return parseWindows(buf, enc); //throw SysError
-        return parseUnix(buf, enc);        //
+            return parseWindows(buf, session); //throw SysError
+        return parseUnix(buf, session);        //
     }
 
     //"ls -l"
-    static std::vector<FtpItem> parseUnix(const std::string& buf, ServerEncoding enc) //throw SysError
+    static std::vector<FtpItem> parseUnix(const std::string& buf, FtpSession& session) //throw SysError
     {
         const std::vector<std::string> lines = splitFtpResponse(buf);
         auto it = lines.begin();
@@ -1254,14 +1283,14 @@ private:
             {
                 try
                 {
-                    parseUnixLine(*it, utcTimeNow, utcCurrentYear, true /*haveGroup*/, enc); //throw SysError
+                    parseUnixLine(*it, utcTimeNow, utcCurrentYear, true /*haveGroup*/, session); //throw SysError
                     return true;
                 }
                 catch (SysError&)
                 {
                     try
                     {
-                        parseUnixLine(*it, utcTimeNow, utcCurrentYear, false /*haveGroup*/, enc); //throw SysError
+                        parseUnixLine(*it, utcTimeNow, utcCurrentYear, false /*haveGroup*/, session); //throw SysError
                         return false;
                     }
                     catch (SysError&) {}
@@ -1269,7 +1298,7 @@ private:
                 }
             }();
 
-            const FtpItem item = parseUnixLine(*it, utcTimeNow, utcCurrentYear, *unixListingHaveGroup_, enc); //throw SysError
+            const FtpItem item = parseUnixLine(*it, utcTimeNow, utcCurrentYear, *unixListingHaveGroup_, session); //throw SysError
             if (item.itemName != Zstr(".") &&
                 item.itemName != Zstr(".."))
                 output.push_back(item);
@@ -1278,7 +1307,7 @@ private:
         return output;
     }
 
-    static FtpItem parseUnixLine(const std::string& rawLine, time_t utcTimeNow, int utcCurrentYear, bool haveGroup, ServerEncoding enc) //throw SysError
+    static FtpItem parseUnixLine(const std::string& rawLine, time_t utcTimeNow, int utcCurrentYear, bool haveGroup, FtpSession& session) //throw SysError
     {
         /*  total 4953                                                  <- optional first line
             drwxr-xr-x 1 root root    4096 Jan 10 11:58 version
@@ -1413,7 +1442,7 @@ private:
             else
                 item.fileSize = fileSize;
 
-            item.itemName = serverToUtfEncoding(itemName, enc); //throw SysError
+            item.itemName = session.serverToUtfEncoding(itemName); //throw SysError
             item.modTime = modTime;
 
             return item;
@@ -1426,7 +1455,7 @@ private:
 
 
     //"dir"
-    static std::vector<FtpItem> parseWindows(const std::string& buf, ServerEncoding enc) //throw SysError
+    static std::vector<FtpItem> parseWindows(const std::string& buf, FtpSession& session) //throw SysError
     {
         /*  Test server: test.rebex.net username:demo pw:password  useTls = true
 
@@ -1541,7 +1570,7 @@ private:
                     FtpItem item;
                     if (isDir)
                         item.type = AFS::ItemType::folder;
-                    item.itemName = serverToUtfEncoding(itemName, enc); //throw SysError
+                    item.itemName = session.serverToUtfEncoding(itemName); //throw SysError
                     item.fileSize = fileSize;
                     item.modTime  = modTime;
 
diff --git a/FreeFileSync/Source/afs/gdrive.cpp b/FreeFileSync/Source/afs/gdrive.cpp
index ddb12f6d..a1b628a7 100644
--- a/FreeFileSync/Source/afs/gdrive.cpp
+++ b/FreeFileSync/Source/afs/gdrive.cpp
@@ -445,11 +445,14 @@ GdriveAccessInfo gdriveExchangeAuthCode(const GdriveAuthCode& authCode, int time
 GdriveAccessInfo gdriveAuthorizeAccess(const std::string& gdriveLoginHint, const std::function<void()>& updateGui /*throw X*/, int timeoutSec) //throw SysError, X
 {
     //spin up a web server to wait for the HTTP GET after Google authentication
-    ::addrinfo hints = {};
-    hints.ai_family   = AF_INET; //make sure our server is reached by IPv4 127.0.0.1, not IPv6 [::1]
-    hints.ai_socktype = SOCK_STREAM; //we *do* care about this one!
-    hints.ai_flags    = AI_PASSIVE; //the returned socket addresses will be suitable for bind(2)ing a socket that will accept(2) connections.
-    hints.ai_flags |= AI_ADDRCONFIG; //no such issue on Linux: https://bugs.chromium.org/p/chromium/issues/detail?id=5234
+    const ::addrinfo hints 
+    {
+    .ai_flags    = AI_PASSIVE //the returned socket addresses will be suitable for bind(2)ing a socket that will accept(2) connections.
+    | AI_ADDRCONFIG //no such issue on Linux: https://bugs.chromium.org/p/chromium/issues/detail?id=5234
+    ,
+    .ai_family   = AF_INET, //make sure our server is reached by IPv4 127.0.0.1, not IPv6 [::1]
+    .ai_socktype = SOCK_STREAM, //we *do* care about this one!
+    };
     ::addrinfo* servinfo = nullptr;
     ZEN_ON_SCOPE_EXIT(if (servinfo) ::freeaddrinfo(servinfo));
 
@@ -1860,12 +1863,12 @@ public:
             if (itemId.empty())
                 break;
 
-            GdriveItemDetails details = {};
+            GdriveItemDetails details = {}; //read in correct sequence!
             details.itemName = utfTo<Zstring>(readContainer<std::string>(stream)); //
             details.type     = readNumber<GdriveItemType>(stream); //
             details.owner    = readNumber     <FileOwner>(stream); //
             details.fileSize = readNumber      <uint64_t>(stream); //SysErrorUnexpectedEos
-            details.modTime  = readNumber       <int64_t>(stream); //
+            details.modTime  = static_cast<time_t>(readNumber<int64_t>(stream)); //
             details.targetId = readContainer<std::string>(stream); //
 
             size_t parentsCount = readNumber<uint32_t>(stream); //SysErrorUnexpectedEos
@@ -1964,10 +1967,12 @@ public:
     {
         if (afsPath.value.empty()) //location root not covered by itemDetails_
         {
-            GdriveItemDetails rootDetails = {};
-            rootDetails.type = GdriveItemType::folder;
-            //rootDetails.itemName =... => better leave empty for a root item!
-            rootDetails.owner = sharedDriveName_.empty() ? FileOwner::me : FileOwner::none;
+            GdriveItemDetails rootDetails
+            {
+                .type = GdriveItemType::folder,
+                //.itemName =... => better leave empty for a root item!
+                .owner = sharedDriveName_.empty() ? FileOwner::me : FileOwner::none,
+            };
             return {locationRootId, std::move(rootDetails)};
         }
 
@@ -2038,12 +2043,14 @@ public:
 
     void notifyFolderCreated(const FileStateDelta& stateDelta, const std::string& folderId, const Zstring& folderName, const std::string& parentId)
     {
-        GdriveItemDetails details = {};
-        details.itemName = folderName;
-        details.type = GdriveItemType::folder;
-        details.owner = FileOwner::me;
-        details.modTime = std::time(nullptr);
-        details.parentIds.push_back(parentId);
+        GdriveItemDetails details
+        {
+            .itemName = folderName,
+            .modTime = std::time(nullptr),
+            .type = GdriveItemType::folder,
+            .owner = FileOwner::me,
+            .parentIds{parentId},
+        };
 
         //avoid needless conflicts due to different Google Drive folder modTime!
         if (auto it = itemDetails_.find(folderId); it != itemDetails_.end())
@@ -2054,13 +2061,15 @@ public:
 
     void notifyShortcutCreated(const FileStateDelta& stateDelta, const std::string& shortcutId, const Zstring& shortcutName, const std::string& parentId, const std::string& targetId)
     {
-        GdriveItemDetails details = {};
-        details.itemName = shortcutName;
-        details.type = GdriveItemType::shortcut;
-        details.owner = FileOwner::me;
-        details.modTime = std::time(nullptr);
-        details.targetId = targetId;
-        details.parentIds.push_back(parentId);
+        GdriveItemDetails details
+        {
+            .itemName = shortcutName,
+            .modTime = std::time(nullptr),
+            .type = GdriveItemType::shortcut,
+            .owner = FileOwner::me,
+            .targetId = targetId,
+            .parentIds{parentId},
+        };
 
         //avoid needless conflicts due to different Google Drive folder modTime!
         if (auto it = itemDetails_.find(shortcutId); it != itemDetails_.end())
@@ -3207,12 +3216,16 @@ struct OutputStreamGdrive : public AFS::OutputStreamImpl
                 //already existing: creates duplicate
 
                 //buffer new file state ASAP (don't wait GDRIVE_SYNC_INTERVAL)
-                GdriveItem newFileItem = {};
-                newFileItem.itemId = fileIdNew;
-                newFileItem.details.itemName = fileName;
-                newFileItem.details.type = GdriveItemType::file;
-                newFileItem.details.owner = FileOwner::me;
-                newFileItem.details.fileSize = asyncStreamIn->getTotalBytesRead();
+                GdriveItem newFileItem
+                {
+                    .itemId = fileIdNew,
+                    .details{
+                        .itemName = fileName,
+                        .fileSize = asyncStreamIn->getTotalBytesRead(),
+                        .type = GdriveItemType::file,
+                        .owner = FileOwner::me,
+                    }
+                };
                 if (modTime) //else: whatever modTime Google Drive selects will be notified after GDRIVE_SYNC_INTERVAL
                     newFileItem.details.modTime = *modTime;
                 newFileItem.details.parentIds.push_back(parentId);
@@ -3611,14 +3624,18 @@ private:
             //buffer new file state ASAP (don't wait GDRIVE_SYNC_INTERVAL)
             accessGlobalFileState(fsTarget.gdriveLogin_, [&](GdriveFileStateAtLocation& fileState) //throw SysError
             {
-                GdriveItem newFileItem = {};
-                newFileItem.itemId = fileIdTrg;
-                newFileItem.details.itemName = itemNameNew;
-                newFileItem.details.type = GdriveItemType::file;
-                newFileItem.details.owner = fileState.all().getSharedDriveName().empty() ? FileOwner::me : FileOwner::none;
-                newFileItem.details.fileSize = itemDetailsSrc.fileSize;
-                newFileItem.details.modTime = itemDetailsSrc.modTime;
-                newFileItem.details.parentIds.push_back(parentIdTrg);
+                const GdriveItem newFileItem
+                {
+                    .itemId = fileIdTrg,
+                    .details{
+                        .itemName = itemNameNew,
+                        .fileSize = itemDetailsSrc.fileSize,
+                        .modTime = itemDetailsSrc.modTime,
+                        .type = GdriveItemType::file,
+                        .owner = fileState.all().getSharedDriveName().empty() ? FileOwner::me : FileOwner::none,
+                        .parentIds{parentIdTrg},
+                    }
+                };
                 fileState.all().notifyItemCreated(aaiTrg.stateDelta, newFileItem);
             });
 
diff --git a/FreeFileSync/Source/afs/native.cpp b/FreeFileSync/Source/afs/native.cpp
index 12b69b3d..8e7a6337 100644
--- a/FreeFileSync/Source/afs/native.cpp
+++ b/FreeFileSync/Source/afs/native.cpp
@@ -174,7 +174,7 @@ std::vector<FsItem> getDirContentFlat(const Zstring& dirPath) //throw FileError
 struct FsItemDetails
 {
     ItemType type;
-    time_t   modTime; //number of seconds since Jan. 1st 1970 UTC
+    time_t   modTime; //number of seconds since Jan. 1st 1970 GMT
     uint64_t fileSize; //unit: bytes!
     AFS::FingerPrint filePrint;
 };
@@ -605,7 +605,7 @@ private:
         catch (FileError&) {});
 
         if (copyFilePermissions)
-            copyItemPermissions(getNativePath(afsSource), nativePathTarget, ProcSymlink::direct); //throw FileError
+            copyItemPermissions(getNativePath(afsSource), nativePathTarget, ProcSymlink::asLink); //throw FileError
     }
 
     //already existing: undefined behavior! (e.g. fail/overwrite)
diff --git a/FreeFileSync/Source/application.cpp b/FreeFileSync/Source/application.cpp
index e9849f80..598eed5c 100644
--- a/FreeFileSync/Source/application.cpp
+++ b/FreeFileSync/Source/application.cpp
@@ -24,7 +24,6 @@
 #include "ui/batch_status_handler.h"
 #include "ui/main_dlg.h"
 #include "base_tools.h"
-//#include "log_file.h"
 #include "ffs_paths.h"
 
     #include <gtk/gtk.h>
@@ -55,10 +54,10 @@ void showSyntaxHelp()
                            setTitle(_("Command line")).
                            setDetailInstructions(_("Syntax:") + L"\n\n" +
                                                  L"FreeFileSync" + L'\n' +
-                                                 L"    [" + _("config files:") + L" *.ffs_gui/*.ffs_batch]" + L'\n' +
-                                                 L"    [-DirPair " + _("directory") + L' ' + _("directory") + L"]" L"\n" +
-                                                 L"    [-Edit]" + L'\n' +
-                                                 L"    [" + _("global config file:") + L" GlobalSettings.xml]" + L"\n\n" +
+                                                 TAB_SPACE + L"[" + _("config files:") + L" *.ffs_gui/*.ffs_batch]" + L'\n' +
+                                                 TAB_SPACE + L"[-DirPair " + _("directory") + L' ' + _("directory") + L"]" L"\n" +
+                                                 TAB_SPACE + L"[-Edit]" + L'\n' +
+                                                 TAB_SPACE + L"[" + _("global config file:") + L" GlobalSettings.xml]" + L"\n\n" +
 
                                                  _("config files:") + L'\n' +
                                                  _("Any number of FreeFileSync \"ffs_gui\" and/or \"ffs_batch\" configuration files.") + L"\n\n" +
@@ -270,7 +269,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
     {
         //parse command line arguments
         std::vector<std::pair<Zstring, Zstring>> dirPathPhrasePairs;
-        std::vector<std::pair<Zstring, XmlType>> configFiles; //XmlType: batch or GUI files only
+        std::vector<Zstring> cfgFilePaths;
         Zstring globalConfigFile;
         bool openForEdit = false;
         {
@@ -351,34 +350,20 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
                 }
                 else
                 {
-                    Zstring filePath = getResolvedFilePath(*it);
-
+                    const Zstring& filePath = getResolvedFilePath(*it);
+#if 0
                     if (!fileAvailable(filePath)) //...be a little tolerant
-                    {
-                        if (fileAvailable(filePath + Zstr(".ffs_batch")))
-                            filePath += Zstr(".ffs_batch");
-                        else if (fileAvailable(filePath + Zstr(".ffs_gui")))
-                            filePath += Zstr(".ffs_gui");
-                        else if (fileAvailable(filePath + Zstr(".xml")))
-                            filePath += Zstr(".xml");
-                        else
-                            throw FileError(replaceCpy(_("Cannot find file %x."), L"%x", fmtPath(filePath)));
-                    }
-
-                    switch (getXmlType(filePath)) //throw FileError
-                    {
-                        case XmlType::gui:
-                            configFiles.emplace_back(filePath, XmlType::gui);
-                            break;
-                        case XmlType::batch:
-                            configFiles.emplace_back(filePath, XmlType::batch);
-                            break;
-                        case XmlType::global:
-                            globalConfigFile = filePath;
-                            break;
-                        case XmlType::other:
-                            throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
-                    }
+                        for (const Zchar* ext : {Zstr(".ffs_gui"), Zstr(".ffs_batch"), Zstr(".xml")})
+                            if (fileAvailable(filePath + ext))
+                                filePath += ext;
+#endif
+                    if (endsWithAsciiNoCase(filePath, Zstr(".ffs_gui")) ||
+                        endsWithAsciiNoCase(filePath, Zstr(".ffs_batch")))
+                        cfgFilePaths.push_back(filePath);
+                    else if (endsWithAsciiNoCase(filePath, Zstr(".xml")))
+                        globalConfigFile = filePath;
+                    else
+                        throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
                 }
         }
         //----------------------------------------------------------------------------------------------------
@@ -415,7 +400,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
         //---------------------------
         const Zstring globalConfigFilePath = !globalConfigFile.empty() ? globalConfigFile : getGlobalConfigDefaultPath();
 
-        if (configFiles.empty())
+        if (cfgFilePaths.empty())
         {
             //gui mode: default startup
             if (dirPathPhrasePairs.empty())
@@ -431,25 +416,25 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
                 runGuiMode(globalConfigFilePath, guiCfg, std::vector<Zstring>(), !openForEdit /*startComparison*/);
             }
         }
-        else if (configFiles.size() == 1)
+        else if (cfgFilePaths.size() == 1)
         {
-            const Zstring filepath = configFiles[0].first;
+            const Zstring filePath = cfgFilePaths[0];
 
             //batch mode
-            if (configFiles[0].second == XmlType::batch && !openForEdit)
+            if (endsWithAsciiNoCase(filePath, Zstr(".ffs_batch")) && !openForEdit)
             {
-                auto [batchCfg, warningMsg] = readBatchConfig(filepath); //throw FileError
+                auto [batchCfg, warningMsg] = readBatchConfig(filePath); //throw FileError
                 if (!warningMsg.empty())
                     throw FileError(warningMsg); //batch mode: break on errors AND even warnings!
 
                 replaceDirectories(batchCfg.mainCfg); //throw FileError
 
-                runBatchMode(globalConfigFilePath, batchCfg, filepath);
+                runBatchMode(globalConfigFilePath, batchCfg, filePath);
             }
             //GUI mode: single config (ffs_gui *or* ffs_batch)
             else
             {
-                auto [guiCfg, warningMsg] = readAnyConfig({filepath}); //throw FileError
+                auto [guiCfg, warningMsg] = readAnyConfig({filePath}); //throw FileError
                 if (!warningMsg.empty())
                     showNotificationDialog(nullptr, DialogInfoType::warning, PopupDialogCfg().setDetailInstructions(warningMsg));
                 //what about simulating changed config on parsing errors?
@@ -458,7 +443,7 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
                 //what about simulating changed config due to directory replacement?
                 //-> propably fine to not show as changed on GUI and not ask user to save on exit!
 
-                runGuiMode(globalConfigFilePath, guiCfg, {filepath}, !openForEdit); //caveat: guiCfg and filepath do not match if directories were set/replaced via command line!
+                runGuiMode(globalConfigFilePath, guiCfg, {filePath}, !openForEdit); //caveat: guiCfg and filepath do not match if directories were set/replaced via command line!
             }
         }
         //gui mode: merged configs
@@ -467,16 +452,12 @@ void Application::launch(const std::vector<Zstring>& commandArgs)
             if (!dirPathPhrasePairs.empty())
                 throw FileError(_("Directories cannot be set for more than one configuration file."));
 
-            std::vector<Zstring> filePaths;
-            for (const auto& [filePath, xmlType] : configFiles)
-                filePaths.push_back(filePath);
-
-            const auto& [guiCfg, warningMsg] = readAnyConfig(filePaths); //throw FileError
+            const auto& [guiCfg, warningMsg] = readAnyConfig(cfgFilePaths); //throw FileError
             if (!warningMsg.empty())
                 showNotificationDialog(nullptr, DialogInfoType::warning, PopupDialogCfg().setDetailInstructions(warningMsg));
             //what about simulating changed config on parsing errors?
 
-            runGuiMode(globalConfigFilePath, guiCfg, filePaths, !openForEdit /*startComparison*/);
+            runGuiMode(globalConfigFilePath, guiCfg, cfgFilePaths, !openForEdit /*startComparison*/);
         }
     }
     catch (const FileError& e)
diff --git a/FreeFileSync/Source/base/algorithm.cpp b/FreeFileSync/Source/base/algorithm.cpp
index 2ce3cd41..df760e4e 100644
--- a/FreeFileSync/Source/base/algorithm.cpp
+++ b/FreeFileSync/Source/base/algorithm.cpp
@@ -565,14 +565,15 @@ private:
         if (dbEntryL && dbEntryR && dbEntryL != dbEntryR) //conflict: which db entry to use?
             return file.setSyncDirConflict(txtDbAmbiguous_);
 
+        if (const InSyncFile* dbEntry = dbEntryL ? dbEntryL : dbEntryR;
+            dbEntry && !stillInSync(*dbEntry, cmpVar_, fileTimeTolerance_, ignoreTimeShiftMinutes_)) //check *before* misleadingly reporting txtNoSideChanged_
+            return file.setSyncDirConflict(txtDbNotInSync_);
+
         const bool changeOnLeft  = !matchesDbEntry<SelectSide::left >(file, dbEntryL, ignoreTimeShiftMinutes_);
         const bool changeOnRight = !matchesDbEntry<SelectSide::right>(file, dbEntryR, ignoreTimeShiftMinutes_);
 
         if (changeOnLeft == changeOnRight)
             file.setSyncDirConflict(changeOnLeft ? txtBothSidesChanged_ : txtNoSideChanged_);
-        else if (const InSyncFile* dbEntry = dbEntryL ? dbEntryL : dbEntryR;
-                 dbEntry && !stillInSync(*dbEntry, cmpVar_, fileTimeTolerance_, ignoreTimeShiftMinutes_))
-            file.setSyncDirConflict(txtDbNotInSync_);
         else
             file.setSyncDir(changeOnLeft ? SyncDirection::right : SyncDirection::left);
     }
@@ -601,14 +602,15 @@ private:
         if (dbEntryL && dbEntryR && dbEntryL != dbEntryR) //conflict: which db entry to use?
             return symlink.setSyncDirConflict(txtDbAmbiguous_);
 
+        if (const InSyncSymlink* dbEntry = dbEntryL ? dbEntryL : dbEntryR;
+            dbEntry && !stillInSync(*dbEntry, cmpVar_, fileTimeTolerance_, ignoreTimeShiftMinutes_))
+            return symlink.setSyncDirConflict(txtDbNotInSync_);
+
         const bool changeOnLeft  = !matchesDbEntry<SelectSide::left >(symlink, dbEntryL, ignoreTimeShiftMinutes_);
         const bool changeOnRight = !matchesDbEntry<SelectSide::right>(symlink, dbEntryR, ignoreTimeShiftMinutes_);
 
         if (changeOnLeft == changeOnRight)
             symlink.setSyncDirConflict(changeOnLeft ? txtBothSidesChanged_ : txtNoSideChanged_);
-        else if (const InSyncSymlink* dbEntry = dbEntryL ? dbEntryL : dbEntryR;
-                 dbEntry && !stillInSync(*dbEntry, cmpVar_, fileTimeTolerance_, ignoreTimeShiftMinutes_))
-            symlink.setSyncDirConflict(txtDbNotInSync_);
         else
             symlink.setSyncDir(changeOnLeft ? SyncDirection::right : SyncDirection::left);
     }
@@ -653,15 +655,18 @@ private:
 
         if (cat != DIR_EQUAL)
         {
-            const bool changeOnLeft  = !matchesDbEntry<SelectSide::left >(folder, dbEntryL);
-            const bool changeOnRight = !matchesDbEntry<SelectSide::right>(folder, dbEntryR);
-
-            if (changeOnLeft == changeOnRight)
-                folder.setSyncDirConflict(changeOnLeft ? txtBothSidesChanged_ : txtNoSideChanged_);
-            else if (dbEntry && !stillInSync(*dbEntry))
+            if (dbEntry && !stillInSync(*dbEntry))
                 folder.setSyncDirConflict(txtDbNotInSync_);
             else
-                folder.setSyncDir(changeOnLeft ? SyncDirection::right : SyncDirection::left);
+            {
+                const bool changeOnLeft  = !matchesDbEntry<SelectSide::left >(folder, dbEntryL);
+                const bool changeOnRight = !matchesDbEntry<SelectSide::right>(folder, dbEntryR);
+
+                if (changeOnLeft == changeOnRight)
+                    folder.setSyncDirConflict(changeOnLeft ? txtBothSidesChanged_ : txtNoSideChanged_);
+                else
+                    folder.setSyncDir(changeOnLeft ? SyncDirection::right : SyncDirection::left);
+            }
         }
 
         recurse(folder, dbEntry);
@@ -669,9 +674,9 @@ private:
 
     //need ref-counted strings! see FileSystemObject::syncDirectionConflict_
     const Zstringc txtBothSidesChanged_ = utfTo<Zstringc>(_("Both sides have changed since last synchronization."));
-    const Zstringc txtNoSideChanged_    = utfTo<Zstringc>(_("Cannot determine sync-direction:") + L'\n' + _("No change since last synchronization."));
-    const Zstringc txtDbNotInSync_      = utfTo<Zstringc>(_("Cannot determine sync-direction:") + L'\n' + _("The database entry is not in sync considering current settings."));
-    const Zstringc txtDbAmbiguous_      = utfTo<Zstringc>(_("Cannot determine sync-direction:") + L'\n' + _("The database entry is ambiguous."));
+    const Zstringc txtNoSideChanged_    = utfTo<Zstringc>(_("Cannot determine sync-direction:") + L'\n' + TAB_SPACE + _("No change since last synchronization."));
+    const Zstringc txtDbNotInSync_      = utfTo<Zstringc>(_("Cannot determine sync-direction:") + L'\n' + TAB_SPACE + _("The database entry is not in sync considering current settings."));
+    const Zstringc txtDbAmbiguous_      = utfTo<Zstringc>(_("Cannot determine sync-direction:") + L'\n' + TAB_SPACE + _("The database entry is ambiguous."));
 
     const CompareVariant cmpVar_;
     const int fileTimeTolerance_;
@@ -915,10 +920,9 @@ private:
                 file.setActive(matchSize<SelectSide::left>(file) &&
                                matchTime<SelectSide::left>(file));
             else
-            {
-                //the only case with partially unclear semantics:
-                //file and time filters may match or not match on each side, leaving a total of 16 combinations for both sides!
-                /*
+                /* the only case with partially unclear semantics:
+                   file and time filters may match or not match on each side, leaving a total of 16 combinations for both sides!
+
                                ST S T -       ST := match size and time
                                ---------       S := match size only
                             ST |I|I|I|I|       T := match time only
@@ -929,13 +933,11 @@ private:
                             ------------       ? := unclear
                              - |I|E|E|E|
                             ------------
-                */
-                //let's set ? := E
+                  let's set ? := E                                          */
                 file.setActive((matchSize<SelectSide::right>(file) &&
                                 matchTime<SelectSide::right>(file)) ||
                                (matchSize<SelectSide::left>(file) &&
                                 matchTime<SelectSide::left>(file)));
-            }
         }
     }
 
@@ -1062,15 +1064,15 @@ void fff::applyTimeSpanFilter(FolderComparison& folderCmp, time_t timeFrom, time
 }
 
 
-std::optional<PathDependency> fff::getPathDependency(const AbstractPath& basePathL, const PathFilter& filterL,
-                                                     const AbstractPath& basePathR, const PathFilter& filterR)
+std::optional<PathDependency> fff::getPathDependency(const AbstractPath& folderPathL, const PathFilter& filterL,
+                                                     const AbstractPath& folderPathR, const PathFilter& filterR)
 {
-    if (!AFS::isNullPath(basePathL) && !AFS::isNullPath(basePathR))
+    if (!AFS::isNullPath(folderPathL) && !AFS::isNullPath(folderPathR))
     {
-        if (basePathL.afsDevice == basePathR.afsDevice)
+        if (folderPathL.afsDevice == folderPathR.afsDevice)
         {
-            const std::vector<Zstring> relPathL = split(basePathL.afsPath.value, FILE_NAME_SEPARATOR, SplitOnEmpty::skip);
-            const std::vector<Zstring> relPathR = split(basePathR.afsPath.value, FILE_NAME_SEPARATOR, SplitOnEmpty::skip);
+            const std::vector<Zstring> relPathL = split(folderPathL.afsPath.value, FILE_NAME_SEPARATOR, SplitOnEmpty::skip);
+            const std::vector<Zstring> relPathR = split(folderPathR.afsPath.value, FILE_NAME_SEPARATOR, SplitOnEmpty::skip);
 
             const bool leftParent = relPathL.size() <= relPathR.size();
 
@@ -1084,8 +1086,6 @@ std::optional<PathDependency> fff::getPathDependency(const AbstractPath& basePat
                 {
                     relDirPath = appendPath(relDirPath, itemName);
                 });
-                const AbstractPath& basePathP = leftParent ? basePathL : basePathR;
-                const AbstractPath& basePathC = leftParent ? basePathR : basePathL;
 
                 const PathFilter& filterP = leftParent ? filterL : filterR;
                 //if there's a dependency, check if the sub directory is (fully) excluded via filter
@@ -1094,7 +1094,7 @@ std::optional<PathDependency> fff::getPathDependency(const AbstractPath& basePat
                 // - user may have manually excluded the conflicting items or changed the filter settings without running a re-compare
                 bool childItemMightMatch = true;
                 if (relDirPath.empty() || filterP.passDirFilter(relDirPath, &childItemMightMatch) || childItemMightMatch)
-                    return PathDependency({basePathP, basePathC, relDirPath});
+                    return PathDependency{leftParent ? folderPathL : folderPathR, relDirPath};
             }
         }
     }
@@ -1231,6 +1231,7 @@ void copyToAlternateFolderFrom(const std::vector<const FileSystemObject*>& rowsT
                     callback.requestUiUpdate(); //throw X  => not reliably covered by PercentStatReporter::updateStatus()! e.g. during first few seconds: STATUS_PERCENT_DELAY!
                 });
                 //result.errorModTime? => probably irrelevant (behave like Windows Explorer)
+                warn_static("no, should be logged at least!")
             });
             statReporter.updateStatus(1, 0); //throw X
         },
diff --git a/FreeFileSync/Source/base/algorithm.h b/FreeFileSync/Source/base/algorithm.h
index 16c9c179..385d3087 100644
--- a/FreeFileSync/Source/base/algorithm.h
+++ b/FreeFileSync/Source/base/algorithm.h
@@ -41,12 +41,11 @@ void setActiveStatus(bool newStatus, FileSystemObject& fsObj);     //activate or
 
 struct PathDependency
 {
-    AbstractPath basePathParent;
-    AbstractPath basePathChild;
+    AbstractPath folderPathParent;
     Zstring relPath; //filled if child path is subfolder of parent path; empty if child path == parent path
 };
-std::optional<PathDependency> getPathDependency(const AbstractPath& basePathL, const PathFilter& filterL,
-                                                const AbstractPath& basePathR, const PathFilter& filterR);
+std::optional<PathDependency> getPathDependency(const AbstractPath& folderPathL, const PathFilter& filterL,
+                                                const AbstractPath& folderPathR, const PathFilter& filterR);
 
 std::pair<std::wstring, int> getSelectedItemsAsString( //returns string with item names and total count of selected(!) items, NOT total files/dirs!
     std::span<const FileSystemObject* const> selectionLeft,   //all pointers need to be bound!
diff --git a/FreeFileSync/Source/base/comparison.cpp b/FreeFileSync/Source/base/comparison.cpp
index 569ddb96..1a1301bc 100644
--- a/FreeFileSync/Source/base/comparison.cpp
+++ b/FreeFileSync/Source/base/comparison.cpp
@@ -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 *
@@ -144,6 +144,8 @@ ResolvedBaseFolders initializeBaseFolders(const std::vector<FolderPairCfg>& fpCf
             }
 
         callback.reportWarning(msg, warnings.warnFoldersDifferInCase); //throw X
+
+        //what about /folder and /Folder/subfolder? => yes, inconsistent, but doesn't matter for FFS
     }
     //---------------------------------------------------------------------------
 
@@ -248,15 +250,15 @@ template <SelectSide side, class FileOrLinkPair> inline
 Zstringc getConflictInvalidDate(const FileOrLinkPair& file)
 {
     return utfTo<Zstringc>(replaceCpy(_("File %x has an invalid date."), L"%x", fmtPath(AFS::getDisplayPath(file.template getAbstractPath<side>()))) + L'\n' +
-                           _("Date:") + L' ' + formatUtcToLocalTime(file.template getLastWriteTime<side>()));
+                           TAB_SPACE + _("Date:") + L' ' + formatUtcToLocalTime(file.template getLastWriteTime<side>()));
 }
 
 
 Zstringc getConflictSameDateDiffSize(const FilePair& file)
 {
     return utfTo<Zstringc>(_("Files have the same date but a different size.") + L'\n' +
-                           arrowLeft  + L' ' + _("Date:") + L' ' + formatUtcToLocalTime(file.getLastWriteTime<SelectSide::left >()) + L"    " + _("Size:") + L' ' + formatNumber(file.getFileSize<SelectSide::left>()) + L'\n' +
-                           arrowRight + L' ' + _("Date:") + L' ' + formatUtcToLocalTime(file.getLastWriteTime<SelectSide::right>()) + L"    " + _("Size:") + L' ' + formatNumber(file.getFileSize<SelectSide::right>()));
+                           TAB_SPACE + arrowLeft  + L' ' + _("Date:") + L' ' + formatUtcToLocalTime(file.getLastWriteTime<SelectSide::left >()) + TAB_SPACE + _("Size:") + L' ' + formatNumber(file.getFileSize<SelectSide::left>()) + L'\n' +
+                           TAB_SPACE + arrowRight + L' ' + _("Date:") + L' ' + formatUtcToLocalTime(file.getLastWriteTime<SelectSide::right>()) + TAB_SPACE + _("Size:") + L' ' + formatNumber(file.getFileSize<SelectSide::right>()));
 }
 
 
@@ -269,8 +271,8 @@ Zstringc getConflictSkippedBinaryComparison()
 Zstringc getDescrDiffMetaShortnameCase(const FileSystemObject& fsObj)
 {
     return utfTo<Zstringc>(_("Items differ in attributes only") + L'\n' +
-                           arrowLeft  + L' ' + fmtPath(fsObj.getItemName<SelectSide::left >()) + L'\n' +
-                           arrowRight + L' ' + fmtPath(fsObj.getItemName<SelectSide::right>()));
+                           TAB_SPACE + arrowLeft  + L' ' + fmtPath(fsObj.getItemName<SelectSide::left >()) + L'\n' +
+                           TAB_SPACE + arrowRight + L' ' + fmtPath(fsObj.getItemName<SelectSide::right>()));
 }
 
 
@@ -279,8 +281,8 @@ template <class FileOrLinkPair>
 Zstringc getDescrDiffMetaData(const FileOrLinkPair& file)
 {
     return utfTo<Zstringc>(_("Items differ in attributes only") + L'\n' +
-                           arrowLeft  + L' ' + _("Date:") + L' ' + formatUtcToLocalTime(file.template getLastWriteTime<SelectSide::left >()) + L'\n' +
-                           arrowRight + L' ' + _("Date:") + L' ' + formatUtcToLocalTime(file.template getLastWriteTime<SelectSide::right>()));
+                           TAB_SPACE + arrowLeft  + L' ' + _("Date:") + L' ' + formatUtcToLocalTime(file.template getLastWriteTime<SelectSide::left >()) + L'\n' +
+                           TAB_SPACE + arrowRight + L' ' + _("Date:") + L' ' + formatUtcToLocalTime(file.template getLastWriteTime<SelectSide::right>()));
 }
 #endif
 
@@ -545,7 +547,6 @@ std::vector<std::shared_ptr<BaseFolderPair>> ComparisonBuffer::compareByContent(
         fpWorkload.push_back({posL, posR, std::move(filesToCompareBytewise)});
     };
 
-    //PERF_START;
     std::vector<std::shared_ptr<BaseFolderPair>> output;
 
     const Zstringc txtConflictSkippedBinaryComparison = getConflictSkippedBinaryComparison(); //avoid premature pess.: save memory via ref-counted string
@@ -711,23 +712,19 @@ const Zstringc* MergeSides::checkFailedRead(FileSystemObject& fsObj, const Zstri
 template <class MapType, class Function>
 void forEachSorted(const MapType& fileMap, Function fun)
 {
-    struct FileRef
-    {
-        Zstring upperCaseName;
-        const typename MapType::value_type* ref;
-    };
+    using FileRef = const typename MapType::value_type*;
+
     std::vector<FileRef> fileList;
-    fileList.reserve(fileMap.size()); //perf: ~5% shorter runtime
+    fileList.reserve(fileMap.size());
 
     for (const auto& item : fileMap)
-        fileList.push_back({getUpperCase(item.first), &item});
+        fileList.push_back(&item);
 
-    //primary sort: ignore Unicode normal form and upper/lower case
-    //=> natural default sequence on file grid UI
-    std::sort(fileList.begin(), fileList.end(), [](const FileRef& lhs, const FileRef& rhs) { return lhs.upperCaseName < rhs.upperCaseName; });
+   //sort for natural default sequence on UI file grid:
+    std::sort(fileList.begin(), fileList.end(), [](const FileRef& lhs, const FileRef& rhs) { return compareNoCase(lhs->first /*item name*/, rhs->first) < 0; });
 
     for (const auto& item : fileList)
-        fun(item.ref->first, item.ref->second);
+        fun(item->first, item->second);
 }
 
 
@@ -761,22 +758,22 @@ void matchFolders(const MapType& mapLeft, const MapType& mapRight, ProcessLeftOn
 {
     struct FileRef
     {
-        Zstring upperCaseName; //buffer expensive getUpperCase() calls!!
+        //perf: buffer ZstringNoCase instead of compareNoCase()/equalNoCase()? => makes no (significant) difference!
         const typename MapType::value_type* ref;
         bool leftSide;
     };
     std::vector<FileRef> fileList;
     fileList.reserve(mapLeft.size() + mapRight.size()); //perf: ~5% shorter runtime
 
-    for (const auto& item : mapLeft ) fileList.push_back({getUpperCase(item.first), &item, true });
-    for (const auto& item : mapRight) fileList.push_back({getUpperCase(item.first), &item, false});
+    for (const auto& item : mapLeft ) fileList.push_back({&item, true });
+    for (const auto& item : mapRight) fileList.push_back({&item, false});
 
     //primary sort: ignore Unicode normal form and upper/lower case
-    //bonus: natural default sequence on file grid UI
-    std::sort(fileList.begin(), fileList.end(), [](const FileRef& lhs, const FileRef& rhs) { return lhs.upperCaseName < rhs.upperCaseName; });
+    //bonus: natural default sequence on UI file grid
+    std::sort(fileList.begin(), fileList.end(), [](const FileRef& lhs, const FileRef& rhs) { return compareNoCase(lhs.ref->first /*item name*/, rhs.ref->first) < 0; });
 
     using ItType = typename std::vector<FileRef>::iterator;
-    auto tryMatchRange = [&](ItType it, ItType itLast) //auto? compiler error on VS 17.2...
+    auto tryMatchRange = [&](ItType it, ItType itLast) //auto parameters? compiler error on VS 17.2...
     {
         const size_t equalCountL = std::count_if(it, itLast, [](const FileRef& fr) { return fr.leftSide; });
         const size_t equalCountR = itLast - it - equalCountL;
@@ -800,7 +797,7 @@ void matchFolders(const MapType& mapLeft, const MapType& mapRight, ProcessLeftOn
     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.upperCaseName != it->upperCaseName; });
+        auto itEndEq = std::find_if(it + 1, fileList.end(), [&](const FileRef& fr) { return !equalNoCase(fr.ref->first, it->ref->first); });
         if (!tryMatchRange(it, itEndEq))
         {
             //secondary sort: respect case, ignore unicode normal forms
@@ -1088,25 +1085,31 @@ FolderComparison fff::compare(WarningDialogs& warnings,
                                    _("The corresponding folder will be considered as empty."), warnings.warnInputFieldEmpty);
     }
 
-    //check whether one side is a sub directory of the other side (folder-pair-wise!)
-    //similar check (warnDependentBaseFolders) if one directory is read/written by multiple pairs not before beginning of synchronization
+    //Check whether one side is a sub directory of the other side (folder-pair-wise!)
+    //The similar check (warnDependentBaseFolders) if one directory is read/written by multiple pairs not before beginning of synchronization
     {
         std::wstring msg;
+        bool shouldExclude = false;
 
         for (const auto& [folderPair, fpCfg] : workLoad)
             if (std::optional<PathDependency> pd = getPathDependency(folderPair.folderPathLeft,  fpCfg.filter.nameFilter.ref(),
                                                                      folderPair.folderPathRight, fpCfg.filter.nameFilter.ref()))
             {
                 msg += L"\n\n" +
-                       AFS::getDisplayPath(folderPair.folderPathLeft) + L'\n' +
+                       AFS::getDisplayPath(folderPair.folderPathLeft) + L" <-> " + 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);
+                {
+                    shouldExclude = true;
+                    msg += std::wstring() + L'\n' + L"⇒ " +
+                           _("Exclude:") + L' ' + utfTo<std::wstring>(FILE_NAME_SEPARATOR + pd->relPath + FILE_NAME_SEPARATOR);
+                }
             }
 
         if (!msg.empty())
-            callback.reportWarning(_("One base folder of a folder pair is contained in the other one.") + L'\n' + //throw X
-                                   _("The folder should be excluded from synchronization via filter.") + msg, warnings.warnDependentFolderPair);
+            callback.reportWarning(_("One base folder of a folder pair is contained in the other one.") +
+                                   (shouldExclude ? L'\n' + _("The folder should be excluded from synchronization via filter.") : L"") +
+                                   msg, warnings.warnDependentFolderPair); //throw X
     }
     //-------------------end of basic checks------------------------------------------
 
diff --git a/FreeFileSync/Source/base/db_file.cpp b/FreeFileSync/Source/base/db_file.cpp
index a509986a..a37e336e 100644
--- a/FreeFileSync/Source/base/db_file.cpp
+++ b/FreeFileSync/Source/base/db_file.cpp
@@ -433,8 +433,8 @@ private:
             const Zstring itemName = readItemName(); //
             const auto cmpVar = static_cast<CompareVariant>(readNumber<int32_t>(streamInSmallNum_)); //
 
-            const InSyncDescrLink dataL(readNumber<int64_t>(streamInBigNum_)); //throw SysErrorUnexpectedEos
-            const InSyncDescrLink dataT(readNumber<int64_t>(streamInBigNum_)); //
+            const InSyncDescrLink dataL{static_cast<time_t>(readNumber<int64_t>(streamInBigNum_))}; //throw SysErrorUnexpectedEos
+            const InSyncDescrLink dataT{static_cast<time_t>(readNumber<int64_t>(streamInBigNum_))}; //
 
             container.addSymlink(itemName,
                                  selectParam<leadSide>(dataL, dataT),
@@ -456,7 +456,7 @@ private:
 
     InSyncDescrFile readFileDescr() //throw SysErrorUnexpectedEos
     {
-        const auto modTime = readNumber<int64_t>(streamInBigNum_); //throw SysErrorUnexpectedEos
+        const auto modTime = static_cast<time_t>(readNumber<int64_t>(streamInBigNum_)); //throw SysErrorUnexpectedEos
 
         AFS::FingerPrint filePrint = 0;
         if (streamVersion_ == 3) //TODO: remove migration code at some time! 2021-02-14
@@ -473,7 +473,7 @@ private:
         else
             filePrint = readNumber<AFS::FingerPrint>(streamInBigNum_); //throw SysErrorUnexpectedEos
 
-        return InSyncDescrFile(modTime, filePrint);
+        return {modTime, filePrint};
     }
 
     //TODO: remove migration code at some time! 2017-02-01
@@ -495,11 +495,11 @@ private:
                 const Zstring itemName = utfTo<Zstring>(readContainer<std::string>(inputBoth_));
                 const auto cmpVar = static_cast<CompareVariant>(readNumber<int32_t>(inputBoth_));
                 const uint64_t fileSize = readNumber<uint64_t>(inputBoth_);
-                const auto modTimeL = readNumber<int64_t>(inputLeft_);
+                const auto modTimeL = static_cast<time_t>(readNumber<int64_t>(inputLeft_));
                 /*const auto fileIdL =*/ readContainer<std::string>(inputLeft_);
-                const auto modTimeR = readNumber<int64_t>(inputRight_);
+                const auto modTimeR = static_cast<time_t>(readNumber<int64_t>(inputRight_));
                 /*const auto fileIdR =*/ readContainer<std::string>(inputRight_);
-                container.addFile(itemName, InSyncDescrFile(modTimeL, AFS::FingerPrint()), InSyncDescrFile(modTimeR, AFS::FingerPrint()), cmpVar, fileSize);
+                container.addFile(itemName, InSyncDescrFile{modTimeL, AFS::FingerPrint()}, InSyncDescrFile{modTimeR, AFS::FingerPrint()}, cmpVar, fileSize);
             }
 
             size_t linkCount = readNumber<uint32_t>(inputBoth_);
@@ -507,9 +507,9 @@ private:
             {
                 const Zstring itemName = utfTo<Zstring>(readContainer<std::string>(inputBoth_));
                 const auto cmpVar = static_cast<CompareVariant>(readNumber<int32_t>(inputBoth_));
-                const auto modTimeL = readNumber<int64_t>(inputLeft_);
-                const auto modTimeR = readNumber<int64_t>(inputRight_);
-                container.addSymlink(itemName, InSyncDescrLink(modTimeL), InSyncDescrLink(modTimeR), cmpVar);
+                const auto modTimeL = static_cast<time_t>(readNumber<int64_t>(inputLeft_));
+                const auto modTimeR = static_cast<time_t>(readNumber<int64_t>(inputRight_));
+                container.addSymlink(itemName, InSyncDescrLink{modTimeL}, InSyncDescrLink{modTimeR}, cmpVar);
             }
 
             size_t dirCount = readNumber<uint32_t>(inputBoth_);
@@ -578,10 +578,10 @@ private:
 
                     //create or update new "in-sync" state
                     dbFiles.insert_or_assign(file.getItemNameAny(),
-                                             InSyncFile(InSyncDescrFile(file.getLastWriteTime<SelectSide::left >(),
-                                                                        file.getFilePrint    <SelectSide::left >()),
-                                                        InSyncDescrFile(file.getLastWriteTime<SelectSide::right>(),
-                                                                        file.getFilePrint    <SelectSide::right>()),
+                                             InSyncFile(InSyncDescrFile{file.getLastWriteTime<SelectSide::left >(),
+                                                                        file.getFilePrint    <SelectSide::left >()},
+                                                        InSyncDescrFile{file.getLastWriteTime<SelectSide::right>(),
+                                                                        file.getFilePrint    <SelectSide::right>()},
                                                         activeCmpVar_,
                                                         file.getFileSize<SelectSide::left>()));
                     toPreserve.insert(file.getItemNameAny());
@@ -618,8 +618,8 @@ private:
 
                     //create or update new "in-sync" state
                     dbSymlinks.insert_or_assign(symlink.getItemNameAny(),
-                                                InSyncSymlink(InSyncDescrLink(symlink.getLastWriteTime<SelectSide::left >()),
-                                                              InSyncDescrLink(symlink.getLastWriteTime<SelectSide::right>()),
+                                                InSyncSymlink(InSyncDescrLink{symlink.getLastWriteTime<SelectSide::left >()},
+                                                              InSyncDescrLink{symlink.getLastWriteTime<SelectSide::right>()},
                                                               activeCmpVar_));
                     toPreserve.insert(symlink.getItemNameAny());
                 }
diff --git a/FreeFileSync/Source/base/db_file.h b/FreeFileSync/Source/base/db_file.h
index 83174c3b..552cdfef 100644
--- a/FreeFileSync/Source/base/db_file.h
+++ b/FreeFileSync/Source/base/db_file.h
@@ -19,18 +19,12 @@ const Zchar SYNC_DB_FILE_ENDING[] = Zstr(".ffs_db"); //don't use Zstring as glob
 
 struct InSyncDescrFile //subset of FileAttributes
 {
-    InSyncDescrFile(time_t modTimeIn, AFS::FingerPrint filePrintIn) :
-        modTime(modTimeIn),
-        filePrint(filePrintIn) {}
-
     time_t modTime = 0;
     AFS::FingerPrint filePrint = 0; //optional!
 };
 
 struct InSyncDescrLink
 {
-    explicit InSyncDescrLink(time_t modTimeIn) : modTime(modTimeIn) {}
-
     time_t modTime = 0;
 };
 
diff --git a/FreeFileSync/Source/base/dir_lock.cpp b/FreeFileSync/Source/base/dir_lock.cpp
index ad2e06f6..ee49cb9d 100644
--- a/FreeFileSync/Source/base/dir_lock.cpp
+++ b/FreeFileSync/Source/base/dir_lock.cpp
@@ -167,9 +167,11 @@ struct LockInformation //throw FileError
 
 LockInformation getLockInfoFromCurrentProcess() //throw FileError
 {
-    LockInformation lockInfo = {};
-    lockInfo.lockId = generateGUID();
-    lockInfo.userId = utfTo<std::string>(getLoginUser()); //throw FileError
+    LockInformation lockInfo =
+    {
+        .lockId = generateGUID(),
+        .userId = utfTo<std::string>(getLoginUser()), //throw FileError
+    };
 
     const std::string osName = "Linux";
 
diff --git a/FreeFileSync/Source/base/file_hierarchy.h b/FreeFileSync/Source/base/file_hierarchy.h
index 1ae07f8c..2062a4ce 100644
--- a/FreeFileSync/Source/base/file_hierarchy.h
+++ b/FreeFileSync/Source/base/file_hierarchy.h
@@ -35,7 +35,7 @@ struct FileAttributes
         static_assert(std::is_signed_v<time_t>, "... and signed!");
     }
 
-    time_t modTime = 0; //number of seconds since Jan. 1st 1970 UTC
+    time_t modTime = 0; //number of seconds since Jan. 1st 1970 GMT
     uint64_t fileSize = 0;
     AFS::FingerPrint filePrint = 0; //optional
     bool isFollowedSymlink = false;
@@ -49,7 +49,7 @@ struct LinkAttributes
     LinkAttributes() {}
     explicit LinkAttributes(time_t modTimeIn) : modTime(modTimeIn) {}
 
-    time_t modTime = 0; //number of seconds since Jan. 1st 1970 UTC
+    time_t modTime = 0; //number of seconds since Jan. 1st 1970 GMT
 };
 
 
@@ -75,7 +75,7 @@ constexpr SelectSide getOtherSide = side == SelectSide::left ? SelectSide::right
 
 
 template <SelectSide side, class T> inline
-static T& selectParam(T& left, T& right)
+T& selectParam(T& left, T& right)
 {
     if constexpr (side == SelectSide::left)
         return left;
@@ -155,7 +155,7 @@ class FileSystemObject;
 
 ------------------------------------------------------------------*/
 
-struct PathInformation //diamond-shaped inheritence!
+struct PathInformation //diamond-shaped inheritance!
 {
     virtual ~PathInformation() {}
 
@@ -296,10 +296,10 @@ public:
     template <SelectSide side> BaseFolderStatus getFolderStatus() const; //base folder status at the time of comparison!
     template <SelectSide side> void setFolderStatus(BaseFolderStatus value); //update after creating the directory in FFS
 
-    //get settings which were used while creating BaseFolderPair
+    //get settings which were used while creating BaseFolderPair:
     const PathFilter&   getFilter() const { return filter_.ref(); }
     CompareVariant getCompVariant() const { return cmpVar_; }
-    int  getFileTimeTolerance() const { return fileTimeTolerance_; }
+    int      getFileTimeTolerance() const { return fileTimeTolerance_; }
     const std::vector<unsigned int>& getIgnoredTimeShift() const { return ignoreTimeShiftMinutes_; }
 
     void flip() override;
@@ -703,6 +703,9 @@ public:
     }
 
 private:
+    RecursiveObjectVisitor           (const RecursiveObjectVisitor&) = delete;
+    RecursiveObjectVisitor& operator=(const RecursiveObjectVisitor&) = delete;
+
     const Function1 onFolder_;
     const Function2 onFile_;
     const Function3 onSymlink_;
diff --git a/FreeFileSync/Source/base/parallel_scan.cpp b/FreeFileSync/Source/base/parallel_scan.cpp
index a0d40da2..2352fec4 100644
--- a/FreeFileSync/Source/base/parallel_scan.cpp
+++ b/FreeFileSync/Source/base/parallel_scan.cpp
@@ -362,7 +362,7 @@ DirCallback::HandleLink DirCallback::onSymlink(const AFS::SymlinkInfo& si) //thr
         case SymLinkHandling::exclude:
             return HandleLink::skip;
 
-        case SymLinkHandling::direct:
+        case SymLinkHandling::asLink:
             if (cfg_.filter.ref().passFileFilter(relPath)) //always use file filter: Link type may not be "stable" on Linux!
             {
                 output_.addSubLink(si.itemName, LinkAttributes(si.modTime));
diff --git a/FreeFileSync/Source/base/path_filter.cpp b/FreeFileSync/Source/base/path_filter.cpp
index ad61cda5..207a4fc6 100644
--- a/FreeFileSync/Source/base/path_filter.cpp
+++ b/FreeFileSync/Source/base/path_filter.cpp
@@ -43,30 +43,30 @@ std::vector<Zstring> fff::splitByDelimiter(const Zstring& filterPhrase)
 void NameFilter::parseFilterPhrase(const Zstring& filterPhrase, FilterSet& filter)
 {
     //normalize filter: 1. ignore Unicode normalization form 2. ignore case
-    Zstring filterPhraseFmt = getUpperCase(filterPhrase);
+    Zstring filterPhraseNorm = getUpperCase(filterPhrase);
     //3. fix path separator
-    if constexpr (FILE_NAME_SEPARATOR != Zstr('/' )) replace(filterPhraseFmt, Zstr('/'),  FILE_NAME_SEPARATOR);
-    if constexpr (FILE_NAME_SEPARATOR != Zstr('\\')) replace(filterPhraseFmt, Zstr('\\'), FILE_NAME_SEPARATOR);
+    if constexpr (FILE_NAME_SEPARATOR != Zstr('/' )) replace(filterPhraseNorm, Zstr('/'),  FILE_NAME_SEPARATOR);
+    if constexpr (FILE_NAME_SEPARATOR != Zstr('\\')) replace(filterPhraseNorm, Zstr('\\'), FILE_NAME_SEPARATOR);
 
+    static_assert(FILE_NAME_SEPARATOR == '/');
     const Zstring sepAsterisk = Zstr("/*");
     const Zstring asteriskSep = Zstr("*/");
-    static_assert(FILE_NAME_SEPARATOR == '/');
 
     auto processTail = [&](const Zstring& phrase)
     {
-        if (endsWith(phrase, FILE_NAME_SEPARATOR) || //only relevant for folder filtering
-            endsWith(phrase, sepAsterisk)) // abc\*
+        if (endsWith(phrase, Zstr(':'))) //file-only tag
+            filter.fileMasks.insert({phrase.begin(), phrase.end() - 1});
+        else if (endsWith(phrase, FILE_NAME_SEPARATOR) || //folder-only tag
+                 endsWith(phrase, sepAsterisk)) // abc\*
+            filter.folderMasks.insert(beforeLast(phrase, FILE_NAME_SEPARATOR, IfNotFoundReturn::none));
+        else
         {
-            const Zstring dirPhrase = beforeLast(phrase, FILE_NAME_SEPARATOR, IfNotFoundReturn::none);
-            if (!dirPhrase.empty())
-                filter.folderMasks.insert(dirPhrase);
+            filter.fileMasks  .insert(phrase);
+            filter.folderMasks.insert(phrase);
         }
-        else if (!phrase.empty())
-            filter.fileFolderMasks.insert(phrase);
     };
 
-    for (const Zstring& itemPhrase : splitByDelimiter(filterPhraseFmt))
-    {
+    for (const Zstring& itemPhrase : splitByDelimiter(filterPhraseNorm))
         /*    phrase  | action
             +---------+--------
             | \blah   | remove \
@@ -78,15 +78,17 @@ void NameFilter::parseFilterPhrase(const Zstring& filterPhrase, FilterSet& filte
             | *\blah  | -> add blah
             | *\*blah | -> add *blah
             +---------+--------
-            | blah\   | remove \; folder only
-            | blah*\  | remove \; folder only
-            | blah\*\ | remove \; folder only
+            | blah:   | remove : (file only)
+            | blah\*: | remove : (file only)
+            +---------+--------
+            | blah\   | remove \ (folder only)
+            | blah*\  | remove \ (folder only)
+            | blah\*\ | remove \ (folder only)
             +---------+--------
             | blah*   |
-            | blah\*  | remove \*; folder only
-            | blah*\* | remove \*; folder only
+            | blah\*  | remove \* (folder only)
+            | blah*\* | remove \* (folder only)
             +---------+--------                    */
-
         if (startsWith(itemPhrase, FILE_NAME_SEPARATOR)) // \abc
             processTail(afterFirst(itemPhrase, FILE_NAME_SEPARATOR, IfNotFoundReturn::none));
         else
@@ -95,13 +97,15 @@ void NameFilter::parseFilterPhrase(const Zstring& filterPhrase, FilterSet& filte
             if (startsWith(itemPhrase, asteriskSep)) // *\abc
                 processTail(afterFirst(itemPhrase, asteriskSep, IfNotFoundReturn::none));
         }
-    }
 }
 
 
 void NameFilter::MaskMatcher::insert(const Zstring& mask)
 {
     assert(mask == getUpperCase(mask));
+    if (mask.empty())
+        return;
+
     if (contains(mask, Zstr('?')) ||
         contains(mask, Zstr('*')))
         realMasks_.insert(mask);
@@ -256,11 +260,11 @@ bool NameFilter::passFileFilter(const Zstring& relFilePath) const
 
     const Zchar* sepPos = findLast(pathFmt.begin(), pathFmt.end(), FILE_NAME_SEPARATOR);
 
-    if (excludeFilter.fileFolderMasks.matches(pathFmt.begin(), pathFmt.end()) || //either match on file or any parent folder
+    if (excludeFilter.fileMasks.matches(pathFmt.begin(), pathFmt.end()) || //either match on file or any parent folder
         (sepPos != pathFmt.end() && excludeFilter.folderMasks.matches(pathFmt.begin(), sepPos))) //match on any parent folder only
         return false;
 
-    return includeFilter.fileFolderMasks.matches(pathFmt.begin(), pathFmt.end()) ||
+    return includeFilter.fileMasks.matches(pathFmt.begin(), pathFmt.end()) ||
            (sepPos != pathFmt.end() && includeFilter.folderMasks.matches(pathFmt.begin(), sepPos));
 }
 
@@ -273,8 +277,7 @@ bool NameFilter::passDirFilter(const Zstring& relDirPath, bool* childItemMightMa
     //normalize input: 1. ignore Unicode normalization form 2. ignore case
     const Zstring& pathFmt = getUpperCase(relDirPath);
 
-    if (excludeFilter.fileFolderMasks.matches(pathFmt.begin(), pathFmt.end()) ||
-        excludeFilter.folderMasks    .matches(pathFmt.begin(), pathFmt.end()))
+    if (excludeFilter.folderMasks.matches(pathFmt.begin(), pathFmt.end()))
     {
         if (childItemMightMatch)
             *childItemMightMatch = false; //perf: no need to traverse deeper; subfolders/subfiles would be excluded by filter anyway!
@@ -286,13 +289,12 @@ bool NameFilter::passDirFilter(const Zstring& relDirPath, bool* childItemMightMa
         return false;
     }
 
-    if (includeFilter.fileFolderMasks.matches(pathFmt.begin(), pathFmt.end()) ||
-        includeFilter.folderMasks    .matches(pathFmt.begin(), pathFmt.end()))
+    if (includeFilter.folderMasks.matches(pathFmt.begin(), pathFmt.end()))
         return true;
 
     if (childItemMightMatch)
-        *childItemMightMatch = includeFilter.fileFolderMasks.matchesBegin(pathFmt) || //might match a file  or folder in subdirectory
-                               includeFilter.folderMasks    .matchesBegin(pathFmt);   //
+        *childItemMightMatch = includeFilter.fileMasks  .matchesBegin(pathFmt) || //might match a file  or folder in subdirectory
+                               includeFilter.folderMasks.matchesBegin(pathFmt);   //
     return false;
 }
 
diff --git a/FreeFileSync/Source/base/path_filter.h b/FreeFileSync/Source/base/path_filter.h
index 4640996c..f7ca25c8 100644
--- a/FreeFileSync/Source/base/path_filter.h
+++ b/FreeFileSync/Source/base/path_filter.h
@@ -115,7 +115,7 @@ private:
 
     struct FilterSet
     {
-        MaskMatcher fileFolderMasks;
+        MaskMatcher fileMasks;
         MaskMatcher folderMasks;
 
         std::strong_ordering operator<=>(const FilterSet&) const = default;
diff --git a/FreeFileSync/Source/base/structures.h b/FreeFileSync/Source/base/structures.h
index da118913..7c95e41f 100644
--- a/FreeFileSync/Source/base/structures.h
+++ b/FreeFileSync/Source/base/structures.h
@@ -29,7 +29,7 @@ enum class CompareVariant
 enum class SymLinkHandling
 {
     exclude,
-    direct,
+    asLink,
     follow
 };
 
diff --git a/FreeFileSync/Source/base/synchronization.cpp b/FreeFileSync/Source/base/synchronization.cpp
index e9958606..7aa49f2e 100644
--- a/FreeFileSync/Source/base/synchronization.cpp
+++ b/FreeFileSync/Source/base/synchronization.cpp
@@ -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 *
@@ -447,6 +447,208 @@ bool significantDifferenceDetected(const SyncStatistics& folderPairStat)
     return nonMatchingRows >= 10 && nonMatchingRows > 0.5 * folderPairStat.rowCount();
 }
 
+//---------------------------------------------------------------------------------------------
+
+struct ChildPathRef
+{
+    const FileSystemObject* fsObj = nullptr;
+    uint64_t childPathHash = 0;
+};
+
+
+template <SelectSide side>
+class GetChildPathsHashed
+{
+public:
+    static std::vector<ChildPathRef> execute(const ContainerObject& folder)
+    {
+        GetChildPathsHashed inst;
+        inst.recurse(folder, FNV1aHash<uint64_t>().get() /*don't start with 0!*/);
+        return std::move(inst.childPathRefs_);
+    }
+
+private:
+    GetChildPathsHashed           (const GetChildPathsHashed&) = delete;
+    GetChildPathsHashed& operator=(const GetChildPathsHashed&) = delete;
+
+    GetChildPathsHashed() {}
+
+    void recurse(const ContainerObject& hierObj, uint64_t parentPathHash)
+    {
+        for (const FilePair& file : hierObj.refSubFiles())
+            if (file.isActive())
+                childPathRefs_.push_back({&file, getPathHash(file, parentPathHash)});
+
+        for (const SymlinkPair& symlink : hierObj.refSubLinks())
+            if (symlink.isActive())
+                childPathRefs_.push_back({&symlink, getPathHash(symlink, parentPathHash)});
+
+        for (const FolderPair& subFolder : hierObj.refSubFolders())
+        {
+            const uint64_t folderPathHash = getPathHash(subFolder, parentPathHash);
+
+            if (subFolder.isActive())
+                childPathRefs_.push_back({&subFolder, folderPathHash});
+
+            recurse(subFolder, folderPathHash);
+        }
+    }
+
+    static uint64_t getPathHash(const FileSystemObject& fsObj, uint64_t parentPathHash)
+    {
+        FNV1aHash<uint64_t> hash(parentPathHash);
+        const Zstring& itemName = fsObj.getItemName<side>();
+
+        if (isAsciiString(itemName)) //fast path: no need for extra memory allocation!
+            for (const Zchar c : itemName)
+                hash.add(asciiToUpper(c));
+        else
+            for (const Zchar c : getUpperCase(itemName))
+                hash.add(c);
+
+        return hash.get();
+    }
+
+    std::vector<ChildPathRef> childPathRefs_;
+};
+
+
+template <SelectSide side>
+bool plannedWriteAccess(const FileSystemObject& fsObj)
+{
+    if (std::optional<SelectSide> dir = getTargetDirection(fsObj.getSyncOperation()))
+        return side == *dir;
+    else
+        return false;
+}
+
+
+template <SelectSide sideL, SelectSide sideR>
+std::weak_ordering comparePathRef(const ChildPathRef& lhs, const ChildPathRef& rhs)
+{
+    if (const std::weak_ordering cmp = lhs.childPathHash <=> rhs.childPathHash;
+        cmp != std::weak_ordering::equivalent)
+        return cmp; //fast path!
+
+    return compareNoCase(lhs.fsObj->getAbstractPath<sideL>().afsPath.value,  //fsObj may come from *different* BaseFolderPair
+                         rhs.fsObj->getAbstractPath<sideR>().afsPath.value); // => don't compare getRelativePath()!
+}
+
+
+template <SelectSide side>
+void sortAndRemoveDuplicates(std::vector<ChildPathRef>& pathRefs)
+{
+    std::sort(pathRefs.begin(), pathRefs.end(), [](const ChildPathRef& lhs, const ChildPathRef& rhs)
+    {
+        if (const std::weak_ordering cmp = comparePathRef<side, side>(lhs, rhs);
+            cmp != std::weak_ordering::equivalent)
+            return cmp < 0;
+
+        return //multiple (case-insensitive) relPaths? => order write-access before read-access, so that std::unique leaves a write if existing!
+            plannedWriteAccess<side>(*lhs.fsObj) >
+            plannedWriteAccess<side>(*rhs.fsObj);
+    });
+
+    pathRefs.erase(std::unique(pathRefs.begin(), pathRefs.end(),
+    [](const ChildPathRef& lhs, const ChildPathRef& rhs) { return comparePathRef<side, side>(lhs, rhs) == std::weak_ordering::equivalent; }),
+    pathRefs.end());
+
+    //let's not use removeDuplicates(): we rely too much on implementation details!
+}
+
+template <SelectSide side>
+std::wstring formatRaceItem(const FileSystemObject& fsObj)
+{
+    return AFS::getDisplayPath(fsObj.base().getAbstractPath<side>()) + (plannedWriteAccess<side>(fsObj) ? L" 💾 "  : L" 👓 " ) +
+           utfTo<std::wstring>(fsObj.getRelativePath<side>()); //e.g. C:\Folder 💾 subfolder\file.txt
+}
+
+struct PathRaceCondition
+{
+    std::wstring itemList;
+    size_t count = 0;
+};
+
+
+template <SelectSide side1, SelectSide side2>
+void getChildItemRaceCondition(std::vector<ChildPathRef>& pathRefs1, std::vector<ChildPathRef>& pathRefs2, PathRaceCondition& result)
+{
+    //use case-sensitive comparison because items were scanned by FFS (=> no messy user input)?
+    //not good enough! E.g. not-yet-existing files are set to be created with different case!
+    // + (weird) a file and a folder are set to be created with same name
+    // => (throw hands in the air) fine, check path only and don't consider case
+
+    sortAndRemoveDuplicates<side1>(pathRefs1);
+    sortAndRemoveDuplicates<side2>(pathRefs2);
+
+    mergeTraversal(pathRefs1.begin(), pathRefs1.end(),
+                   pathRefs2.begin(), pathRefs2.end(),
+    [](const ChildPathRef&) {} /*left only*/,
+    [&](const ChildPathRef& lhs, const ChildPathRef& rhs)
+    {
+        if (plannedWriteAccess<side1>(*lhs.fsObj) ||
+            plannedWriteAccess<side2>(*rhs.fsObj))
+        {
+            if (result.count < CONFLICTS_PREVIEW_MAX)
+                result.itemList += formatRaceItem<side1>(*lhs.fsObj) + L"\n" +
+                                   formatRaceItem<side2>(*rhs.fsObj) + L"\n\n";
+            ++result.count;
+        }
+    },
+    [](const ChildPathRef&) {} /*right only*/, comparePathRef<side1, side2>);
+}
+
+
+//check if some files/folders are included more than once and form a race condition (:= multiple accesses of which at least one is a write)
+// - checking filter for subfolder exclusion is not good enough: one folder may have a *.txt include-filter, the other a *.lng include filter => still no dependencies
+// - user may have manually excluded the conflicting items or changed the filter settings without running a re-compare
+template <SelectSide sideP, SelectSide sideC>
+void getPathRaceCondition(const BaseFolderPair& baseFolderP, const BaseFolderPair& baseFolderC, PathRaceCondition& result)
+{
+    const AbstractPath basePathP = baseFolderP.getAbstractPath<sideP>(); //parent/child notion is tentative at this point
+    const AbstractPath basePathC = baseFolderC.getAbstractPath<sideC>(); //=> will be swapped if necessary
+
+    if (!AFS::isNullPath(basePathP) && !AFS::isNullPath(basePathC))
+        if (basePathP.afsDevice == basePathC.afsDevice)
+        {
+            if (basePathP.afsPath.value.size() > basePathC.afsPath.value.size())
+                return getPathRaceCondition<sideC, sideP>(baseFolderC, baseFolderP, result);
+
+            const std::vector<Zstring> relPathP = split(basePathP.afsPath.value, FILE_NAME_SEPARATOR, SplitOnEmpty::skip);
+            const std::vector<Zstring> relPathC = split(basePathC.afsPath.value, FILE_NAME_SEPARATOR, SplitOnEmpty::skip);
+
+            if (relPathP.size() <= relPathC.size() &&
+            /**/std::equal(relPathP.begin(), relPathP.end(), relPathC.begin(), [](const Zstring& lhs, const Zstring& rhs) { return equalNoCase(lhs, rhs); }))
+            {
+                //=> at this point parent/child folders are confirmed
+                //now find child folder match inside baseFolderP
+                //e.g.  C:\folder <-> C:\folder\sub    =>  find "sub" inside C:\folder
+                std::vector<const ContainerObject*> childFolderP{&baseFolderP};
+
+                std::for_each(relPathC.begin() + relPathP.size(), relPathC.end(), [&](const Zstring& itemName)
+                {
+                    std::vector<const ContainerObject*> childFolderP2;
+
+                    for (const ContainerObject* childFolder : childFolderP)
+                        for (const FolderPair& folder : childFolder->refSubFolders())
+                            if (equalNoCase(folder.getItemName<sideP>(), itemName))
+                                childFolderP2.push_back(&folder);
+                    //no "break"? yes, weird, but there could be more than one (for case-sensitive file system)
+
+                    childFolderP = std::move(childFolderP2);
+                });
+
+                std::vector<ChildPathRef> pathRefsP;
+                for (const ContainerObject* childFolder : childFolderP)
+                    append(pathRefsP, GetChildPathsHashed<sideP>::execute(*childFolder));
+
+                std::vector<ChildPathRef> pathRefsC = GetChildPathsHashed<sideC>::execute(baseFolderC);
+
+                getChildItemRaceCondition<sideP, sideC>(pathRefsP, pathRefsC, result);
+            }
+        }
+}
+
 //#################################################################################################################
 
 //--------------------- data verification -------------------------
@@ -2227,11 +2429,11 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
 
     //-------------------execute basic checks all at once BEFORE starting sync--------------------------------------
 
-    std::vector<int /*we really want bool*/> skipFolderPair(folderCmp.size(), false); //folder pairs may be skipped after fatal errors were found
+    std::vector<unsigned char /*we really want bool*/> skipFolderPair(folderCmp.size(), false); //folder pairs may be skipped after fatal errors were found
 
-    std::map<const BaseFolderPair*, std::pair<int, std::vector<SyncStatistics::ConflictInfo>>> checkUnresolvedConflicts;
+    std::vector<std::tuple<const BaseFolderPair*, int /*conflict count*/, std::vector<SyncStatistics::ConflictInfo>>> checkUnresolvedConflicts;
 
-    std::vector<std::tuple<AbstractPath, const PathFilter*, bool /*write access*/>> checkReadWriteBaseFolders;
+    std::vector<std::tuple<const BaseFolderPair*, SelectSide, bool /*write access*/>> checkBaseFolderRaceCondition;
 
     std::vector<std::pair<AbstractPath, AbstractPath>> checkSignificantDiffPairs;
 
@@ -2246,17 +2448,17 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
     std::set<AbstractPath> checkVersioningLimitPaths;
 
     //------------------- start checking folder pairs -------------------
-    for (auto itBase = begin(folderCmp); itBase != end(folderCmp); ++itBase)
+    for (size_t folderIndex = 0; folderIndex < folderCmp.size(); ++folderIndex)
     {
-        BaseFolderPair& baseFolder = *itBase;
-        const size_t folderIndex = itBase - begin(folderCmp);
-        const FolderPairSyncCfg& folderPairCfg  = syncConfig     [folderIndex];
+        BaseFolderPair&          baseFolder     = *folderCmp[folderIndex];
+        const FolderPairSyncCfg& folderPairCfg  = syncConfig[folderIndex];
         const SyncStatistics&    folderPairStat = folderPairStats[folderIndex];
 
         const AbstractPath versioningFolderPath = createAbstractPath(folderPairCfg.versioningFolderPhrase);
 
-        //aggregate *all* conflicts:
-        checkUnresolvedConflicts[&baseFolder] = std::pair(folderPairStat.conflictCount(), folderPairStat.getConflictsPreview());
+        //prepare conflict preview:
+        if (folderPairStat.conflictCount() > 0)
+            checkUnresolvedConflicts.emplace_back(&baseFolder, folderPairStat.conflictCount(), folderPairStat.getConflictsPreview());
 
         //consider *all* paths that might be used during versioning limit at some time
         if (folderPairCfg.handleDeletion == DeletionPolicy::versioning &&
@@ -2268,7 +2470,7 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
         //================ begin of checks that may SKIP folder pairs ===================
         //===============================================================================
 
-        //exclude a few pathological cases (including empty left, right folders)
+        //exclude a few pathological cases:
         if (baseFolder.getAbstractPath<SelectSide::left >() ==
             baseFolder.getAbstractPath<SelectSide::right>())
         {
@@ -2311,7 +2513,7 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
             continue;
         }
 
-        //allow propagation of deletions only from *null-* or *existing* source folder:
+        //allow propagation of deletions only from *empty* or *existing* source folder:
         auto sourceFolderMissing = [&](const AbstractPath& baseFolderPath, BaseFolderStatus folderStatus) //we need to evaluate existence status from time of comparison!
         {
             if (!AFS::isNullPath(baseFolderPath))
@@ -2349,13 +2551,13 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
 
             //prepare: check if versioning path itself will be synchronized (and was not excluded via filter)
             checkVersioningPaths.insert(versioningFolderPath);
-            checkVersioningBasePaths.emplace_back(baseFolder.getAbstractPath<SelectSide::left >(), &baseFolder.getFilter());
-            checkVersioningBasePaths.emplace_back(baseFolder.getAbstractPath<SelectSide::right>(), &baseFolder.getFilter());
         }
+        checkVersioningBasePaths.emplace_back(baseFolder.getAbstractPath<SelectSide::left >(), &baseFolder.getFilter());
+        checkVersioningBasePaths.emplace_back(baseFolder.getAbstractPath<SelectSide::right>(), &baseFolder.getFilter());
 
-        //prepare: check if folders are used by multiple pairs in read/write access
-        checkReadWriteBaseFolders.emplace_back(baseFolder.getAbstractPath<SelectSide::left >(), &baseFolder.getFilter(), writeLeft);
-        checkReadWriteBaseFolders.emplace_back(baseFolder.getAbstractPath<SelectSide::right>(), &baseFolder.getFilter(), writeRight);
+        //prepare: check if some files are used by multiple pairs in read/write access
+        checkBaseFolderRaceCondition.emplace_back(&baseFolder, SelectSide::left,  writeLeft);
+        checkBaseFolderRaceCondition.emplace_back(&baseFolder, SelectSide::right, writeRight);
 
         //check if more than 50% of total number of files/dirs are to be created/overwritten/deleted
         if (!AFS::isNullPath(baseFolder.getAbstractPath<SelectSide::left >()) &&
@@ -2412,29 +2614,51 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
                 checkRecycler(baseFolder.getAbstractPath<SelectSide::right>());
         }
     }
-    //-----------------------------------------------------------------
+    //--------------------------------------------------------------------------------------
 
     //check if unresolved conflicts exist
-    if (std::any_of(checkUnresolvedConflicts.begin(), checkUnresolvedConflicts.end(), [](const auto& item) { return item.second.first > 0; }))
+    if (!checkUnresolvedConflicts.empty())
     {
-        std::wstring msg = _("The following items have unresolved conflicts and will not be synchronized:");
+        //distribute CONFLICTS_PREVIEW_MAX over all pairs, not *per* pair, or else log size with many folder pairs can blow up!
+        std::vector<std::vector<SyncStatistics::ConflictInfo>> conflictPreviewTrim(checkUnresolvedConflicts.size());
 
-        for (const auto& [baseFolder, conflicts] : checkUnresolvedConflicts)
+        size_t previewRemain = CONFLICTS_PREVIEW_MAX;
+        for (size_t i = 0; ; ++i)
         {
-            const auto& [conflictCount, conflictPreview] = conflicts;
-            if (conflictCount > 0)
-            {
-                msg += L"\n\n" + _("Folder pair:") + L' ' +
-                       AFS::getDisplayPath(baseFolder->getAbstractPath<SelectSide::left >()) + L" <-> " +
-                       AFS::getDisplayPath(baseFolder->getAbstractPath<SelectSide::right>());
+            const size_t previewRemainOld = previewRemain;
 
-                for (const SyncStatistics::ConflictInfo& item : conflictPreview)
-                    msg += L'\n' + utfTo<std::wstring>(item.relPath) + L": " + item.msg;
+            for (size_t j = 0; j < checkUnresolvedConflicts.size(); ++j)
+            {
+                const auto& [baseFolder, conflictCount, conflictPreview] = checkUnresolvedConflicts[j];
 
-                if (makeUnsigned(conflictCount) > conflictPreview.size())
-                    msg += L"\n  [...]  " + replaceCpy(_P("Showing %y of 1 item", "Showing %y of %x items", conflictCount), //%x used as plural form placeholder!
-                                                       L"%y", formatNumber(conflictPreview.size()));
+                if (i < conflictPreview.size())
+                {
+                    conflictPreviewTrim[j].push_back(conflictPreview[i]);
+                    if (--previewRemain == 0)
+                        goto break2; //sigh
+                }
             }
+            if (previewRemain == previewRemainOld)
+                break;
+        }
+break2:
+
+        std::wstring msg = _("The following items have unresolved conflicts and will not be synchronized:");
+
+        auto itPrevi = conflictPreviewTrim.begin();
+        for (const auto& [baseFolder, conflictCount, conflictPreview] : checkUnresolvedConflicts)
+        {
+            msg += L"\n\n" + _("Folder pair:") + L' ' +
+                   AFS::getDisplayPath(baseFolder->getAbstractPath<SelectSide::left >()) + L" <-> " +
+                   AFS::getDisplayPath(baseFolder->getAbstractPath<SelectSide::right>());
+
+            for (const SyncStatistics::ConflictInfo& item : *itPrevi)
+                msg += L'\n' + utfTo<std::wstring>(item.relPath) + L": " + item.msg;
+
+            if (makeUnsigned(conflictCount) > itPrevi->size())
+                msg += L"\n  [...]  " + replaceCpy(_P("Showing %y of 1 item", "Showing %y of %x items", conflictCount), //%x used as plural form placeholder!
+                                                   L"%y", formatNumber(itPrevi->size()));
+            ++itPrevi;
         }
 
         callback.reportWarning(msg, warnings.warnUnresolvedConflicts);
@@ -2460,8 +2684,8 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
 
         for (const auto& [folderPath, space] : checkDiskSpaceMissing)
             msg += L"\n\n" + AFS::getDisplayPath(folderPath) + L'\n' +
-                   _("Required:")  + L' ' + formatFilesizeShort(space.first)  + L'\n' +
-                   _("Available:") + L' ' + formatFilesizeShort(space.second);
+                   TAB_SPACE + _("Required:")  + L' ' + formatFilesizeShort(space.first)  + L'\n' +
+                   TAB_SPACE + _("Available:") + L' ' + formatFilesizeShort(space.second);
 
         callback.reportWarning(msg, warnings.warnNotEnoughDiskSpace);
     }
@@ -2480,35 +2704,41 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
 
     //check if folders are used by multiple pairs in read/write access
     {
-        std::set<AbstractPath> dependentFolders;
+        PathRaceCondition conflicts;
 
         //race condition := multiple accesses of which at least one is a write
-        for (auto it = checkReadWriteBaseFolders.begin(); it != checkReadWriteBaseFolders.end(); ++it)
-        {
-            const auto& [basePath1, filter1, writeAccess1] = *it;
-            if (writeAccess1)
-                for (auto it2 = checkReadWriteBaseFolders.begin(); it2 != checkReadWriteBaseFolders.end(); ++it2)
+        //=> use "writeAccess" to reduce list of - not necessarily conflicting - candidates to check (=> perf!)
+        for (auto it = checkBaseFolderRaceCondition.begin(); it != checkBaseFolderRaceCondition.end(); ++it)
+            if (const auto& [baseFolder1, side1, writeAccess1] = *it;
+                writeAccess1)
+                for (auto it2 = checkBaseFolderRaceCondition.begin(); it2 != checkBaseFolderRaceCondition.end(); ++it2)
                 {
-                    const auto& [basePath2, filter2, writeAccess2] = *it2;
+                    const auto& [baseFolder2, side2, writeAccess2] = *it2;
 
                     if (!writeAccess2 ||
                         it < it2) //avoid duplicate comparisons
-                        if (std::optional<PathDependency> pd = getPathDependency(basePath1, *filter1,
-                                                                                 basePath2, *filter2))
-                        {
-                            dependentFolders.insert(pd->basePathParent);
-                            dependentFolders.insert(pd->basePathChild);
-                        }
+                    {
+                        //"The Things We Do for [Perf]"
+                        /**/ if (side1 == SelectSide::left  && side2 == SelectSide::left ) getPathRaceCondition<SelectSide::left,  SelectSide::left >(*baseFolder1, *baseFolder2, conflicts);
+                        else if (side1 == SelectSide::left  && side2 == SelectSide::right) getPathRaceCondition<SelectSide::left,  SelectSide::right>(*baseFolder1, *baseFolder2, conflicts);
+                        else if (side1 == SelectSide::right && side2 == SelectSide::left ) getPathRaceCondition<SelectSide::right, SelectSide::left >(*baseFolder1, *baseFolder2, conflicts);
+                        else                                                               getPathRaceCondition<SelectSide::right, SelectSide::right>(*baseFolder1, *baseFolder2, conflicts);
+                    }
                 }
-        }
+        assert(makeUnsigned(std::count(conflicts.itemList.begin(), conflicts.itemList.end(), L'\n')) == 3 * std::min(conflicts.count, CONFLICTS_PREVIEW_MAX));
 
-        if (!dependentFolders.empty())
+        if (conflicts.count > 0)
         {
             std::wstring msg = _("Some files will be synchronized as part of multiple base folders.") + L'\n' +
-                               _("To avoid conflicts, set up exclude filters so that each updated file is included by only one base folder.") + L'\n';
+                               _("To avoid conflicts, set up exclude filters so that each updated file is included by only one base folder.") + L"\n\n" +
+                               conflicts.itemList;
 
-            for (const AbstractPath& baseFolderPath : dependentFolders)
-                msg += L'\n' + AFS::getDisplayPath(baseFolderPath);
+            assert(endsWith(conflicts.itemList, L"\n\n"));
+            if (conflicts.count > CONFLICTS_PREVIEW_MAX)
+                msg += L"[...]  " + replaceCpy(_P("Showing %y of 1 item", "Showing %y of %x items", conflicts.count), //%x used as plural form placeholder!
+                                               L"%y", formatNumber(CONFLICTS_PREVIEW_MAX));
+            else
+                trim(msg);
 
             callback.reportWarning(msg, warnings.warnDependentBaseFolders);
         }
@@ -2517,26 +2747,34 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
     //check if versioning path itself will be synchronized (and was not excluded via filter)
     {
         std::wstring msg;
+        bool shouldExclude = false;
+
         for (const AbstractPath& versioningFolderPath : checkVersioningPaths)
         {
-            std::map<AbstractPath, std::wstring> uniqueMsgs; //=> at most one msg per base folder (*and* per versioningFolderPath)
+            std::set<AbstractPath> foldersWithWarnings; //=> at most one msg per base folder (*and* per versioningFolderPath)
 
             for (const auto& [folderPath, filter] : checkVersioningBasePaths) //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(folderPath);
-                    if (pd->basePathParent == folderPath && !pd->relPath.empty())
-                        line += L'\n' + _("Exclude:") + L" \t" + utfTo<std::wstring>(FILE_NAME_SEPARATOR + pd->relPath + FILE_NAME_SEPARATOR);
-
-                    uniqueMsgs[folderPath] = line;
-                }
-            for (const auto& [folderPath, perFolderMsg] : uniqueMsgs)
-                msg += perFolderMsg;
+                    if (const auto [it, inserted] = foldersWithWarnings.insert(folderPath);
+                        inserted)
+                    {
+                        msg += L"\n\n" +
+                               _("Base folder:")       + L" \t" + AFS::getDisplayPath(folderPath) + L'\n' +
+                               _("Versioning folder:") + L" \t" + AFS::getDisplayPath(versioningFolderPath);
+                        if (pd->folderPathParent == folderPath) //else: probably fine? :>
+                            if (!pd->relPath.empty())
+                            {
+                                shouldExclude = true;
+                                msg += std::wstring() + L'\n' + L"⇒ " +
+                                       _("Exclude:") + L" \t" + utfTo<std::wstring>(FILE_NAME_SEPARATOR + pd->relPath + FILE_NAME_SEPARATOR);
+                            }
+                        warn_static("else: ???")
+                    }
         }
         if (!msg.empty())
-            callback.reportWarning(_("The versioning folder is contained in a base folder.") + L'\n' +
-                                   _("The folder should be excluded from synchronization via filter.") + msg, warnings.warnVersioningFolderPartOfSync);
+            callback.reportWarning(_("The versioning folder is contained in a base folder.") +
+                                   (shouldExclude ? L'\n' + _("The folder should be excluded from synchronization via filter.") : L"") +
+                                   msg, warnings.warnVersioningFolderPartOfSync);
     }
 
     //warn if versioning folder paths differ only in case => possible pessimization for applyVersioningLimit()
@@ -2558,6 +2796,7 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
                 }
             callback.reportWarning(msg, warnings.warnFoldersDifferInCase); //throw X
         }
+                //what about /folder and /Folder/subfolder? => yes, inconsistent, but doesn't matter for FFS
     }
     //-------------------end of basic checks------------------------------------------
 
@@ -2622,11 +2861,10 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
     try
     {
         //loop through all directory pairs
-        for (auto itBase = begin(folderCmp); itBase != end(folderCmp); ++itBase)
+        for (size_t folderIndex = 0; folderIndex < folderCmp.size(); ++folderIndex)
         {
-            BaseFolderPair& baseFolder = *itBase;
-            const size_t folderIndex = itBase - begin(folderCmp);
-            const FolderPairSyncCfg& folderPairCfg  = syncConfig     [folderIndex];
+            BaseFolderPair&          baseFolder     = *folderCmp[folderIndex];
+            const FolderPairSyncCfg& folderPairCfg  = syncConfig[folderIndex];
             const SyncStatistics&    folderPairStat = folderPairStats[folderIndex];
 
             if (skipFolderPair[folderIndex]) //folder pairs may be skipped after fatal errors were found
@@ -2634,8 +2872,8 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
 
             //------------------------------------------------------------------------------------------
             callback.logInfo(_("Synchronizing folder pair:") + L' ' + getVariantNameWithSymbol(folderPairCfg.syncVar) + L'\n' + //throw X
-                             L"    " + AFS::getDisplayPath(baseFolder.getAbstractPath<SelectSide::left >()) + L'\n' +
-                             L"    " + AFS::getDisplayPath(baseFolder.getAbstractPath<SelectSide::right>()));
+                             TAB_SPACE + AFS::getDisplayPath(baseFolder.getAbstractPath<SelectSide::left >()) + L'\n' +
+                             TAB_SPACE + AFS::getDisplayPath(baseFolder.getAbstractPath<SelectSide::right>()));
             //------------------------------------------------------------------------------------------
 
             //checking a second time: 1. a long time may have passed since syncing the previous folder pairs!
@@ -2734,15 +2972,15 @@ void fff::synchronize(const std::chrono::system_clock::time_point& syncStartTime
             //(try to gracefully) write database file
             if (folderPairCfg.saveSyncDB)
             {
-                saveLastSynchronousState(baseFolder, failSafeFileCopy, //throw X
-                                         callback /*throw X*/);
-                guardDbSave.dismiss(); //[!] after "graceful" try: user might have cancelled during DB write: ensure DB is still written
+                saveLastSynchronousState(baseFolder, failSafeFileCopy,
+                                         callback /*throw X*/); //throw X
+                guardDbSave.dismiss(); //[!] dismiss *after* "graceful" try: user might cancel during DB write: ensure DB is still written
             }
         }
         //-----------------------------------------------------------------------------------------------------
 
         applyVersioningLimit(versionLimitFolders,
-                             callback /*throw X*/);
+                             callback /*throw X*/); //throw X
     }
     catch (const std::exception& e)
     {
diff --git a/FreeFileSync/Source/base/versioning.cpp b/FreeFileSync/Source/base/versioning.cpp
index 6627b242..1a17c6b2 100644
--- a/FreeFileSync/Source/base/versioning.cpp
+++ b/FreeFileSync/Source/base/versioning.cpp
@@ -399,7 +399,7 @@ std::weak_ordering fff::operator<=>(const VersioningLimitFolder& lhs, const Vers
 
 
 void fff::applyVersioningLimit(const std::set<VersioningLimitFolder>& folderLimits,
-                               PhaseCallback& callback /*throw X*/)
+                               PhaseCallback& callback /*throw X*/) //throw X
 {
     //--------- determine existing folder paths for traversal ---------
     std::set<DirectoryKey> foldersToRead;
@@ -423,7 +423,7 @@ void fff::applyVersioningLimit(const std::set<VersioningLimitFolder>& folderLimi
                                                                    false /*allowUserInteraction*/, callback); //throw X
             foldersToRead.clear();
             for (const AbstractPath& folderPath : status.existing)
-                foldersToRead.insert(DirectoryKey({folderPath, makeSharedRef<NullFilter>(), SymLinkHandling::direct}));
+                foldersToRead.insert(DirectoryKey({folderPath, makeSharedRef<NullFilter>(), SymLinkHandling::asLink}));
 
             if (!status.failedChecks.empty())
             {
diff --git a/FreeFileSync/Source/base_tools.cpp b/FreeFileSync/Source/base_tools.cpp
index dd6f3f11..e642463a 100644
--- a/FreeFileSync/Source/base_tools.cpp
+++ b/FreeFileSync/Source/base_tools.cpp
@@ -59,25 +59,25 @@ void fff::logNonDefaultSettings(const XmlGlobalSettings& activeSettings, PhaseCa
     std::wstring changedSettingsMsg;
 
     if (activeSettings.failSafeFileCopy != defaultSettings.failSafeFileCopy)
-        changedSettingsMsg += L"\n    " + _("Fail-safe file copy") + L" - " + (activeSettings.failSafeFileCopy ? _("Enabled") : _("Disabled"));
+        changedSettingsMsg += L"\n" + (TAB_SPACE + _("Fail-safe file copy")) + L" - " + (activeSettings.failSafeFileCopy ? _("Enabled") : _("Disabled"));
 
     if (activeSettings.copyLockedFiles != defaultSettings.copyLockedFiles)
-        changedSettingsMsg += L"\n    " + _("Copy locked files") + L" - " + (activeSettings.copyLockedFiles ? _("Enabled") : _("Disabled"));
+        changedSettingsMsg += L"\n" + (TAB_SPACE + _("Copy locked files")) + L" - " + (activeSettings.copyLockedFiles ? _("Enabled") : _("Disabled"));
 
     if (activeSettings.copyFilePermissions != defaultSettings.copyFilePermissions)
-        changedSettingsMsg += L"\n    " + _("Copy file access permissions") + L" - " + (activeSettings.copyFilePermissions ? _("Enabled") : _("Disabled"));
+        changedSettingsMsg += L"\n" + (TAB_SPACE + _("Copy file access permissions")) + L" - " + (activeSettings.copyFilePermissions ? _("Enabled") : _("Disabled"));
 
     if (activeSettings.fileTimeTolerance != defaultSettings.fileTimeTolerance)
-        changedSettingsMsg += L"\n    " + _("File time tolerance") + L" - " + numberTo<std::wstring>(activeSettings.fileTimeTolerance);
+        changedSettingsMsg += L"\n" + (TAB_SPACE + _("File time tolerance")) + L" - " + numberTo<std::wstring>(activeSettings.fileTimeTolerance);
 
     if (activeSettings.runWithBackgroundPriority != defaultSettings.runWithBackgroundPriority)
-        changedSettingsMsg += L"\n    " + _("Run with background priority") + L" - " + (activeSettings.runWithBackgroundPriority ? _("Enabled") : _("Disabled"));
+        changedSettingsMsg += L"\n" + (TAB_SPACE + _("Run with background priority")) + L" - " + (activeSettings.runWithBackgroundPriority ? _("Enabled") : _("Disabled"));
 
     if (activeSettings.createLockFile != defaultSettings.createLockFile)
-        changedSettingsMsg += L"\n    " + _("Lock directories during sync") + L" - " + (activeSettings.createLockFile ? _("Enabled") : _("Disabled"));
+        changedSettingsMsg += L"\n" + (TAB_SPACE + _("Lock directories during sync")) + L" - " + (activeSettings.createLockFile ? _("Enabled") : _("Disabled"));
 
     if (activeSettings.verifyFileCopy != defaultSettings.verifyFileCopy)
-        changedSettingsMsg += L"\n    " + _("Verify copied files") + L" - " + (activeSettings.verifyFileCopy ? _("Enabled") : _("Disabled"));
+        changedSettingsMsg += L"\n" + (TAB_SPACE + _("Verify copied files")) + L" - " + (activeSettings.verifyFileCopy ? _("Enabled") : _("Disabled"));
 
     if (!changedSettingsMsg.empty())
         callback.logInfo(_("Using non-default global settings:") + changedSettingsMsg); //throw X
diff --git a/FreeFileSync/Source/config.cpp b/FreeFileSync/Source/config.cpp
index 4c4bdc66..21bb4e0c 100644
--- a/FreeFileSync/Source/config.cpp
+++ b/FreeFileSync/Source/config.cpp
@@ -23,7 +23,7 @@ using namespace fff; //required for correct overload resolution!
 namespace
 {
 //-------------------------------------------------------------------------------------------------------------------------------
-const int XML_FORMAT_GLOBAL_CFG = 24; //2022-04-29
+const int XML_FORMAT_GLOBAL_CFG = 25; //2022-08-26
 const int XML_FORMAT_SYNC_CFG   = 17; //2020-10-14
 //-------------------------------------------------------------------------------------------------------------------------------
 }
@@ -39,53 +39,6 @@ const ExternalApp fff::extCommandOpenDefault
 {L"Open with default application", "xdg-open \"%local_path%\""};
 
 
-XmlType getXmlTypeNoThrow(const XmlDoc& doc) //noexcept
-{
-    if (doc.root().getName() == "FreeFileSync")
-    {
-        std::string type;
-        if (doc.root().getAttribute("XmlType", type))
-        {
-            if (type == "GUI")
-                return XmlType::gui;
-            else if (type == "BATCH")
-                return XmlType::batch;
-            else if (type == "GLOBAL")
-                return XmlType::global;
-        }
-    }
-    return XmlType::other;
-}
-
-
-XmlType fff::getXmlType(const Zstring& filePath) //throw FileError
-{
-    //quick exit if file is not an XML
-    XmlDoc doc = loadXml(filePath); //throw FileError
-    return ::getXmlTypeNoThrow(doc);
-}
-
-
-void setXmlType(XmlDoc& doc, XmlType type) //throw()
-{
-    switch (type)
-    {
-        case XmlType::gui:
-            doc.root().setAttribute("XmlType", "GUI");
-            break;
-        case XmlType::batch:
-            doc.root().setAttribute("XmlType", "BATCH");
-            break;
-        case XmlType::global:
-            doc.root().setAttribute("XmlType", "GLOBAL");
-            break;
-        case XmlType::other:
-            assert(false);
-            break;
-    }
-}
-
-
 
 
 XmlGlobalSettings::XmlGlobalSettings() :
@@ -436,7 +389,7 @@ void writeText(const SymLinkHandling& value, std::string& output)
         case SymLinkHandling::exclude:
             output = "Exclude";
             break;
-        case SymLinkHandling::direct:
+        case SymLinkHandling::asLink:
             output = "Direct";
             break;
         case SymLinkHandling::follow:
@@ -452,7 +405,7 @@ bool readText(const std::string& input, SymLinkHandling& value)
     if (tmp == "Exclude")
         value = SymLinkHandling::exclude;
     else if (tmp == "Direct")
-        value = SymLinkHandling::direct;
+        value = SymLinkHandling::asLink;
     else if (tmp == "Follow")
         value = SymLinkHandling::follow;
     else
@@ -1271,32 +1224,32 @@ void readConfig(const XmlIn& in, LocalPairConfig& lpc, std::map<AfsDevice, size_
 
 void readConfig(const XmlIn& in, MainConfiguration& mainCfg, int formatVer)
 {
-    XmlIn inMain = formatVer < 10 ? in["MainConfig"] : in; //TODO: remove if parameter migration after some time! 2018-02-25
+    XmlIn in2 = formatVer < 10 ? in["MainConfig"] : in; //TODO: remove if parameter migration after some time! 2018-02-25
 
     if (formatVer < 10) //TODO: remove if parameter migration after some time! 2018-02-25
-        readConfig(inMain["Comparison"], mainCfg.cmpCfg);
+        readConfig(in2["Comparison"], mainCfg.cmpCfg);
     else
-        readConfig(inMain["Compare"], mainCfg.cmpCfg);
+        readConfig(in2["Compare"], mainCfg.cmpCfg);
     //###########################################################
 
     //read sync configuration
     if (formatVer < 10) //TODO: remove if parameter migration after some time! 2018-02-25
-        readConfig(inMain["SyncConfig"], mainCfg.syncCfg, mainCfg.deviceParallelOps, formatVer);
+        readConfig(in2["SyncConfig"], mainCfg.syncCfg, mainCfg.deviceParallelOps, formatVer);
     else
-        readConfig(inMain["Synchronize"], mainCfg.syncCfg, mainCfg.deviceParallelOps, formatVer);
+        readConfig(in2["Synchronize"], mainCfg.syncCfg, mainCfg.deviceParallelOps, formatVer);
 
     //###########################################################
 
     //read filter settings
     if (formatVer < 10) //TODO: remove if parameter migration after some time! 2018-02-25
-        readConfig(inMain["GlobalFilter"], mainCfg.globalFilter);
+        readConfig(in2["GlobalFilter"], mainCfg.globalFilter);
     else
-        readConfig(inMain["Filter"], mainCfg.globalFilter);
+        readConfig(in2["Filter"], mainCfg.globalFilter);
 
     //###########################################################
     //read folder pairs
     bool firstItem = true;
-    for (XmlIn inPair = inMain["FolderPairs"]["Pair"]; inPair; inPair.next())
+    for (XmlIn inPair = in2["FolderPairs"]["Pair"]; inPair; inPair.next())
     {
         LocalPairConfig lpc;
         readConfig(inPair, lpc, mainCfg.deviceParallelOps, formatVer);
@@ -1317,28 +1270,28 @@ void readConfig(const XmlIn& in, MainConfiguration& mainCfg, int formatVer)
     else
         //TODO: remove if parameter migration after some time! 2018-02-24
         if (formatVer < 10)
-            inMain["IgnoreErrors"](mainCfg.ignoreErrors);
+            in2["IgnoreErrors"](mainCfg.ignoreErrors);
         else
         {
-            inMain["Errors"].attribute("Ignore", mainCfg.ignoreErrors);
-            inMain["Errors"].attribute("Retry",  mainCfg.autoRetryCount);
-            inMain["Errors"].attribute("Delay",  mainCfg.autoRetryDelay);
+            in2["Errors"].attribute("Ignore", mainCfg.ignoreErrors);
+            in2["Errors"].attribute("Retry",  mainCfg.autoRetryCount);
+            in2["Errors"].attribute("Delay",  mainCfg.autoRetryDelay);
         }
 
     //TODO: remove if parameter migration after some time! 2017-10-24
     if (formatVer < 8)
-        inMain["OnCompletion"](mainCfg.postSyncCommand);
+        in2["OnCompletion"](mainCfg.postSyncCommand);
     else
     {
-        inMain["PostSyncCommand"](mainCfg.postSyncCommand);
-        inMain["PostSyncCommand"].attribute("Condition", mainCfg.postSyncCondition);
+        in2["PostSyncCommand"](mainCfg.postSyncCommand);
+        in2["PostSyncCommand"].attribute("Condition", mainCfg.postSyncCondition);
     }
 
     //TODO: remove if parameter migration after some time! 2018-08-13
     if (formatVer < 14)
         ; //path will be extracted from BatchExclusiveConfig
     else
-        inMain["LogFolder"](mainCfg.altLogFolderPathPhrase);
+        in2["LogFolder"](mainCfg.altLogFolderPathPhrase);
 
     //TODO: remove after migration! 2020-04-24
     if (formatVer < 16)
@@ -1349,8 +1302,8 @@ void readConfig(const XmlIn& in, MainConfiguration& mainCfg, int formatVer)
         ;
     else
     {
-        inMain["EmailNotification"](mainCfg.emailNotifyAddress);
-        inMain["EmailNotification"].attribute("Condition", mainCfg.emailNotifyCondition);
+        in2["EmailNotification"](mainCfg.emailNotifyAddress);
+        in2["EmailNotification"].attribute("Condition", mainCfg.emailNotifyCondition);
     }
 }
 
@@ -1594,6 +1547,10 @@ void readConfig(const XmlIn& in, XmlGlobalSettings& cfg, int formatVer)
         inOpt["WarnVersioningFolderPartOfSync"].attribute("Show", cfg.warnDlgs.warnVersioningFolderPartOfSync);
     }
 
+    //TODO: remove after migration! 2022-08-26
+    if (formatVer < 25)
+        cfg.warnDlgs.warnDependentBaseFolders = true; //new semantics! should not be ignored
+
     //TODO: remove after migration! 2021-12-02
     if (formatVer < 23)
     {
@@ -2100,11 +2057,21 @@ std::pair<ConfigType, std::wstring /*warningMsg*/> parseConfig(const XmlDoc& doc
 
 
 template <class ConfigType>
-std::pair<ConfigType, std::wstring /*warningMsg*/> readConfig(const Zstring& filePath, XmlType type, int currentXmlFormatVer) //throw FileError
+std::pair<ConfigType, std::wstring /*warningMsg*/> readConfig(const Zstring& filePath, const char* expectedCfgType, int currentXmlFormatVer) //throw FileError
 {
     XmlDoc doc = loadXml(filePath); //throw FileError
 
-    if (getXmlTypeNoThrow(doc) != type) //noexcept
+    const std::string cfgType =[&]
+    {
+        if (doc.root().getName() == "FreeFileSync")
+        {
+            std::string type;
+            if (doc.root().getAttribute("XmlType", type))
+                return type;
+        }
+        return std::string();
+    }();
+    if (cfgType != expectedCfgType)
         throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
 
     return parseConfig<ConfigType>(doc, filePath, currentXmlFormatVer);
@@ -2114,19 +2081,19 @@ std::pair<ConfigType, std::wstring /*warningMsg*/> readConfig(const Zstring& fil
 
 std::pair<XmlGuiConfig, std::wstring /*warningMsg*/> fff::readGuiConfig(const Zstring& filePath)
 {
-    return readConfig<XmlGuiConfig>(filePath, XmlType::gui, XML_FORMAT_SYNC_CFG); //throw FileError
+    return readConfig<XmlGuiConfig>(filePath, "GUI", XML_FORMAT_SYNC_CFG); //throw FileError
 }
 
 
 std::pair<XmlBatchConfig, std::wstring /*warningMsg*/> fff::readBatchConfig(const Zstring& filePath)
 {
-    return readConfig<XmlBatchConfig>(filePath, XmlType::batch, XML_FORMAT_SYNC_CFG); //throw FileError
+    return readConfig<XmlBatchConfig>(filePath, "BATCH", XML_FORMAT_SYNC_CFG); //throw FileError
 }
 
 
 std::pair<XmlGlobalSettings, std::wstring /*warningMsg*/> fff::readGlobalConfig(const Zstring& filePath)
 {
-    return readConfig<XmlGlobalSettings>(filePath, XmlType::global, XML_FORMAT_GLOBAL_CFG); //throw FileError
+    return readConfig<XmlGlobalSettings>(filePath, "GLOBAL", XML_FORMAT_GLOBAL_CFG); //throw FileError
 }
 
 
@@ -2140,41 +2107,31 @@ std::pair<XmlGuiConfig, std::wstring /*warningMsg*/> fff::readAnyConfig(const st
 
     for (auto it = filePaths.begin(); it != filePaths.end(); ++it)
     {
-        const Zstring& filePath = *it;
         const bool firstItem = it == filePaths.begin(); //init all non-"mainCfg" settings with first config file
+        const Zstring& filePath = *it;
 
-        XmlDoc doc = loadXml(filePath); //throw FileError
-
-        switch (getXmlTypeNoThrow(doc))
+        if (endsWithAsciiNoCase(filePath, Zstr(".ffs_gui")))
         {
-            case XmlType::gui:
-            {
-                const auto& [guiCfg, warningMsg] = parseConfig<XmlGuiConfig>(doc, filePath, XML_FORMAT_SYNC_CFG); //nothrow
-                if (firstItem)
-                    cfg = guiCfg;
-                mainCfgs.push_back(guiCfg.mainCfg);
-
-                if (!warningMsg.empty())
-                    warningMsgAll += warningMsg + L"\n\n";
-            }
-            break;
+            const auto& [guiCfg, warningMsg] = readGuiConfig(filePath); //throw FileError
+            if (firstItem)
+                cfg = guiCfg;
+            mainCfgs.push_back(guiCfg.mainCfg);
 
-            case XmlType::batch:
-            {
-                const auto& [batchCfg, warningMsg] = parseConfig<XmlBatchConfig>(doc, filePath, XML_FORMAT_SYNC_CFG); //nothrow
-                if (firstItem)
-                    cfg = convertBatchToGui(batchCfg);
-                mainCfgs.push_back(batchCfg.mainCfg);
-
-                if (!warningMsg.empty())
-                    warningMsgAll += warningMsg + L"\n\n";
-            }
-            break;
+            if (!warningMsg.empty())
+                warningMsgAll += warningMsg + L"\n\n";
+        }
+        else if (endsWithAsciiNoCase(filePath, Zstr(".ffs_batch")))
+        {
+            const auto& [batchCfg, warningMsg] = readBatchConfig(filePath); //throw FileError
+            if (firstItem)
+                cfg = convertBatchToGui(batchCfg);
+            mainCfgs.push_back(batchCfg.mainCfg);
 
-            case XmlType::global:
-            case XmlType::other:
-                throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
+            if (!warningMsg.empty())
+                warningMsgAll += warningMsg + L"\n\n";
         }
+        else
+            throw FileError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(filePath)));
     }
     cfg.mainCfg = merge(mainCfgs);
 
@@ -2293,41 +2250,36 @@ void writeConfig(const LocalPairConfig& lpc, const std::map<AfsDevice, size_t>&
 
 void writeConfig(const MainConfiguration& mainCfg, XmlOut& out)
 {
-    XmlOut outMain = out;
-
-    XmlOut outCmp = outMain["Compare"];
-
+    XmlOut outCmp = out["Compare"];
     writeConfig(mainCfg.cmpCfg, outCmp);
     //###########################################################
 
-    XmlOut outSync = outMain["Synchronize"];
-
+    XmlOut outSync = out["Synchronize"];
     writeConfig(mainCfg.syncCfg, mainCfg.deviceParallelOps, outSync);
     //###########################################################
 
-    XmlOut outFilter = outMain["Filter"];
-    //write filter settings
+    XmlOut outFilter = out["Filter"];
     writeConfig(mainCfg.globalFilter, outFilter);
 
     //###########################################################
-    XmlOut outFp = outMain["FolderPairs"];
+    XmlOut outFp = out["FolderPairs"];
     //write folder pairs
     writeConfig(mainCfg.firstPair, mainCfg.deviceParallelOps, outFp);
 
     for (const LocalPairConfig& lpc : mainCfg.additionalPairs)
         writeConfig(lpc, mainCfg.deviceParallelOps, outFp);
 
-    outMain["Errors"].attribute("Ignore", mainCfg.ignoreErrors);
-    outMain["Errors"].attribute("Retry",  mainCfg.autoRetryCount);
-    outMain["Errors"].attribute("Delay",  mainCfg.autoRetryDelay);
+    out["Errors"].attribute("Ignore", mainCfg.ignoreErrors);
+    out["Errors"].attribute("Retry",  mainCfg.autoRetryCount);
+    out["Errors"].attribute("Delay",  mainCfg.autoRetryDelay);
 
-    outMain["PostSyncCommand"](mainCfg.postSyncCommand);
-    outMain["PostSyncCommand"].attribute("Condition", mainCfg.postSyncCondition);
+    out["PostSyncCommand"](mainCfg.postSyncCommand);
+    out["PostSyncCommand"].attribute("Condition", mainCfg.postSyncCondition);
 
-    outMain["LogFolder"](mainCfg.altLogFolderPathPhrase);
+    out["LogFolder"](mainCfg.altLogFolderPathPhrase);
 
-    outMain["EmailNotification"](mainCfg.emailNotifyAddress);
-    outMain["EmailNotification"].attribute("Condition", mainCfg.emailNotifyCondition);
+    out["EmailNotification"](mainCfg.emailNotifyAddress);
+    out["EmailNotification"].attribute("Condition", mainCfg.emailNotifyCondition);
 }
 
 
@@ -2528,11 +2480,10 @@ void writeConfig(const XmlGlobalSettings& cfg, XmlOut& out)
 
 
 template <class ConfigType>
-void writeConfig(const ConfigType& cfg, XmlType type, int xmlFormatVer, const Zstring& filePath)
+void writeConfig(const ConfigType& cfg, const char* cfgType, int xmlFormatVer, const Zstring& filePath)
 {
     XmlDoc doc("FreeFileSync");
-    setXmlType(doc, type); //throw()
-
+    doc.root().setAttribute("XmlType", cfgType);
     doc.root().setAttribute("XmlFormat", xmlFormatVer);
 
     XmlOut out(doc);
@@ -2544,19 +2495,19 @@ void writeConfig(const ConfigType& cfg, XmlType type, int xmlFormatVer, const Zs
 
 void fff::writeConfig(const XmlGuiConfig& cfg, const Zstring& filePath)
 {
-    ::writeConfig(cfg, XmlType::gui, XML_FORMAT_SYNC_CFG, filePath); //throw FileError
+    ::writeConfig(cfg, "GUI", XML_FORMAT_SYNC_CFG, filePath); //throw FileError
 }
 
 
 void fff::writeConfig(const XmlBatchConfig& cfg, const Zstring& filePath)
 {
-    ::writeConfig(cfg, XmlType::batch, XML_FORMAT_SYNC_CFG, filePath); //throw FileError
+    ::writeConfig(cfg, "BATCH", XML_FORMAT_SYNC_CFG, filePath); //throw FileError
 }
 
 
 void fff::writeConfig(const XmlGlobalSettings& cfg, const Zstring& filePath)
 {
-    ::writeConfig(cfg, XmlType::global, XML_FORMAT_GLOBAL_CFG, filePath); //throw FileError
+    ::writeConfig(cfg, "GLOBAL", XML_FORMAT_GLOBAL_CFG, filePath); //throw FileError
 }
 
 
diff --git a/FreeFileSync/Source/config.h b/FreeFileSync/Source/config.h
index 9e7c0a39..74e05cdb 100644
--- a/FreeFileSync/Source/config.h
+++ b/FreeFileSync/Source/config.h
@@ -20,16 +20,6 @@
 
 namespace fff
 {
-enum class XmlType
-{
-    gui,
-    batch,
-    global,
-    other
-};
-XmlType getXmlType(const Zstring& filePath); //throw FileError
-
-
 enum class BatchErrorHandling
 {
     showPopup,
@@ -185,7 +175,7 @@ struct XmlGlobalSettings
             int           syncOverdueDays = 7;
             ColumnTypeCfg lastSortColumn = cfgGridLastSortColumnDefault;
             bool          lastSortAscending = getDefaultSortDirection(cfgGridLastSortColumnDefault);
-            size_t histItemsMax = 100;
+            size_t histItemsMax = 100; //do we need to limit config items at all?
             Zstring lastSelectedFile;
             std::vector<ConfigFileItem> fileHistory;
             std::vector<Zstring>        lastUsedFiles;
@@ -253,7 +243,7 @@ struct XmlGlobalSettings
 
     std::vector<ExternalApp> externalApps{extCommandFileManager, extCommandOpenDefault};
 
-    time_t lastUpdateCheck = 0; //number of seconds since 00:00 hours, Jan 1, 1970 UTC
+    time_t lastUpdateCheck = 0; //number of seconds since Jan 1, 1970 GMT
     std::string lastOnlineVersion;
 
     std::string welcomeShownVersion; //last FFS version for which the welcome dialog was shown
diff --git a/FreeFileSync/Source/localization.cpp b/FreeFileSync/Source/localization.cpp
index 0d653b34..d0aa5692 100644
--- a/FreeFileSync/Source/localization.cpp
+++ b/FreeFileSync/Source/localization.cpp
@@ -114,11 +114,13 @@ std::vector<TranslationInfo> loadTranslations(const Zstring& zipPath) //throw Fi
             else
                 assert(false);
     }
-    catch (FileError&) //fall back to folder
+    catch (FileError&) //fall back to folder: dev build (only!?)
     {
         const Zstring fallbackFolder = beforeLast(zipPath, Zstr(".zip"), IfNotFoundReturn::none);
-        if (dirAvailable(fallbackFolder)) //Debug build (only!?)
-            traverseFolder(fallbackFolder, [&](const FileInfo& fi)
+        if (!itemStillExists(fallbackFolder)) //throw FileError
+            throw;
+
+        traverseFolder(fallbackFolder, [&](const FileInfo& fi)
         {
             if (endsWith(fi.fullPath, Zstr(".lng")))
             {
@@ -126,23 +128,22 @@ std::vector<TranslationInfo> loadTranslations(const Zstring& zipPath) //throw Fi
                 streams.emplace_back(fi.itemName, std::move(stream));
             }
         }, nullptr, nullptr, [](const std::wstring& errorMsg) { throw FileError(errorMsg); });
-        else
-            throw;
     }
     //--------------------------------------------------------------------
 
-    std::vector<TranslationInfo> translations;
+    std::vector<TranslationInfo> translations
     {
         //default entry:
-        TranslationInfo newEntry;
-        newEntry.languageID     = wxLANGUAGE_ENGLISH_US;
-        newEntry.languageName   = L"English";
-        newEntry.translatorName = L"Zenju";
-        newEntry.languageFlag   = "flag_usa";
-        newEntry.lngFileName    = Zstr("");
-        newEntry.lngStream      = "";
-        translations.push_back(newEntry);
-    }
+        {
+            .languageID     = wxLANGUAGE_ENGLISH_US,
+            .locale         = "en_US",
+            .languageName   = L"English",
+            .translatorName = L"Zenju",
+            .languageFlag   = "flag_usa",
+            .lngFileName    = Zstr(""),
+            .lngStream      = "",
+        }
+    };
 
     for (/*const*/ auto& [fileName, stream] : streams)
         try
@@ -150,22 +151,22 @@ std::vector<TranslationInfo> loadTranslations(const Zstring& zipPath) //throw Fi
             const lng::TransHeader lngHeader = lng::parseHeader(stream); //throw ParsingError
             assert(!lngHeader.languageName  .empty());
             assert(!lngHeader.translatorName.empty());
-            assert(!lngHeader.localeName    .empty());
+            assert(!lngHeader.locale        .empty());
             assert(!lngHeader.flagFile      .empty());
 
-            const wxLanguageInfo* lngInfo = wxLocale::FindLanguageInfo(utfTo<wxString>(lngHeader.localeName));
-            assert(lngInfo && lngInfo->CanonicalName == utfTo<wxString>(lngHeader.localeName));
+            const wxLanguageInfo* lngInfo = wxLocale::FindLanguageInfo(utfTo<wxString>(lngHeader.locale));
+            assert(lngInfo && lngInfo->CanonicalName == utfTo<wxString>(lngHeader.locale));
             if (lngInfo)
+                translations.push_back(
             {
-                TranslationInfo newEntry;
-                newEntry.languageID     = static_cast<wxLanguage>(lngInfo->Language);
-                newEntry.languageName   = utfTo<std::wstring>(lngHeader.languageName);
-                newEntry.translatorName = utfTo<std::wstring>(lngHeader.translatorName);
-                newEntry.languageFlag   = lngHeader.flagFile;
-                newEntry.lngFileName    = fileName;
-                newEntry.lngStream      = std::move(stream);
-                translations.push_back(std::move(newEntry));
-            }
+                .languageID     = static_cast<wxLanguage>(lngInfo->Language),
+                .locale         = lngHeader.locale,
+                .languageName   = utfTo<std::wstring>(lngHeader.languageName),
+                .translatorName = utfTo<std::wstring>(lngHeader.translatorName),
+                .languageFlag   = lngHeader.flagFile,
+                .lngFileName    = fileName,
+                .lngStream      = std::move(stream),
+            });
         }
         catch (lng::ParsingError&) { assert(false); }
 
@@ -278,13 +279,13 @@ public:
 
     wxMsgCatalog* LoadCatalog(const wxString& domain, const wxString& lang) override
     {
+        //"lang" is NOT (exactly) what we return from GetAvailableTranslations(), but has a little "extra", e.g.: de_DE.WINDOWS-1252 or ar.WINDOWS-1252
         auto extractIsoLangCode = [](wxString langCode)
         {
             langCode = beforeLast(langCode, L".", IfNotFoundReturn::all);
             return beforeLast(langCode, L"_", IfNotFoundReturn::all);
         };
 
-        //"lang" is NOT (exactly) what we return from GetAvailableTranslations(), but has a little "extra", e.g.: de_DE.WINDOWS-1252 or ar.WINDOWS-1252
         if (equalAsciiNoCase(extractIsoLangCode(lang), extractIsoLangCode(canonicalName_)))
             return wxMsgCatalog::CreateFromData(wxScopedCharBuffer::CreateNonOwned(moBuf_.ref().c_str(), moBuf_.ref().size()), domain);
         assert(false);
diff --git a/FreeFileSync/Source/localization.h b/FreeFileSync/Source/localization.h
index f7161541..3672e6f5 100644
--- a/FreeFileSync/Source/localization.h
+++ b/FreeFileSync/Source/localization.h
@@ -18,6 +18,7 @@ namespace fff
 struct TranslationInfo
 {
     wxLanguage languageID = wxLANGUAGE_UNKNOWN;
+    std::string locale;
     std::wstring languageName;
     std::wstring translatorName;
     std::string languageFlag;
diff --git a/FreeFileSync/Source/log_file.cpp b/FreeFileSync/Source/log_file.cpp
index 77817898..71255ba5 100644
--- a/FreeFileSync/Source/log_file.cpp
+++ b/FreeFileSync/Source/log_file.cpp
@@ -25,7 +25,7 @@ const int SEPARATION_LINE_LEN = 40;
 
 std::string generateLogHeaderTxt(const ProcessSummary& s, const ErrorLog& log, int logPreviewFailsMax)
 {
-    const std::string tabSpace(4, ' '); //4: the only sensible space count for tabs
+    const auto tabSpace = utfTo<std::string>(TAB_SPACE);
 
     std::string headerLine;
     for (const std::wstring& jobName : s.jobNames)
diff --git a/FreeFileSync/Source/parse_lng.h b/FreeFileSync/Source/parse_lng.h
index 48a2dd81..7af4766d 100644
--- a/FreeFileSync/Source/parse_lng.h
+++ b/FreeFileSync/Source/parse_lng.h
@@ -28,7 +28,7 @@ struct TransHeader
 {
     std::string languageName;     //display name: "English (UK)"
     std::string translatorName;   //"Zenju"
-    std::string localeName;       //ISO 639 language code + ISO 3166 country code, e.g. "en_GB", or "en_US"
+    std::string locale;           //ISO 639 language code + (optional) ISO 3166 country code, e.g. "de", "en_GB", or "en_US"
     std::string flagFile;         //"england.png"
     int pluralCount = 0;          //2
     std::string pluralDefinition; //"n == 1 ? 0 : 1"
@@ -166,8 +166,8 @@ enum class TokenType
     langNameEnd,
     transNameBegin,
     transNameEnd,
-    localeNameBegin,
-    localeNameEnd,
+    localeBegin,
+    localeEnd,
     flagFileBegin,
     flagFileEnd,
     pluralCountBegin,
@@ -223,8 +223,8 @@ private:
         {TokenType::langNameEnd,      "</language>"},
         {TokenType::transNameBegin,   "<translator>"},
         {TokenType::transNameEnd,     "</translator>"},
-        {TokenType::localeNameBegin,  "<locale>"},
-        {TokenType::localeNameEnd,    "</locale>"},
+        {TokenType::localeBegin,      "<locale>"},
+        {TokenType::localeEnd,        "</locale>"},
         {TokenType::flagFileBegin,    "<image>"},
         {TokenType::flagFileEnd,      "</image>"},
         {TokenType::pluralCountBegin, "<plural_count>"},
@@ -373,10 +373,10 @@ public:
         consumeToken(TokenType::text);         //throw ParsingError
         consumeToken(TokenType::transNameEnd); //
 
-        consumeToken(TokenType::localeNameBegin); //throw ParsingError
-        header.localeName = token().text;
+        consumeToken(TokenType::localeBegin); //throw ParsingError
+        header.locale = token().text;
         consumeToken(TokenType::text);          //throw ParsingError
-        consumeToken(TokenType::localeNameEnd); //
+        consumeToken(TokenType::localeEnd); //
 
         consumeToken(TokenType::flagFileBegin); //throw ParsingError
         header.flagFile = token().text;
@@ -506,7 +506,7 @@ private:
                 throw ParsingError({L"Source text ends with an ellipsis \"...\", but translation does not", scn_.posRow(), scn_.posCol()});
 
             //check for not-to-be-translated texts
-            for (const char* fixedStr : {"FreeFileSync", "RealTimeSync", "ffs_gui", "ffs_batch", "ffs_tmp", "GlobalSettings.xml"})
+            for (const char* fixedStr : {"FreeFileSync", "RealTimeSync", "ffs_gui", "ffs_batch", "ffs_real", "ffs_tmp", "GlobalSettings.xml"})
                 if (contains(original, fixedStr) && !contains(translation, fixedStr))
                     throw ParsingError({replaceCpy<std::wstring>(L"Misspelled \"%x\" in translation", L"%x", utfTo<std::wstring>(fixedStr)), scn_.posRow(), scn_.posCol()});
 
@@ -757,9 +757,9 @@ std::string generateLng(const TranslationUnorderedList& in, const TransHeader& h
     out += header.translatorName;
     out += tokens.text(TokenType::transNameEnd) + '\n';
 
-    out += '\t' + tokens.text(TokenType::localeNameBegin);
-    out += header.localeName;
-    out += tokens.text(TokenType::localeNameEnd) + '\n';
+    out += '\t' + tokens.text(TokenType::localeBegin);
+    out += header.locale;
+    out += tokens.text(TokenType::localeEnd) + '\n';
 
     out += '\t' + tokens.text(TokenType::flagFileBegin);
     out += header.flagFile;
diff --git a/FreeFileSync/Source/ui/batch_config.cpp b/FreeFileSync/Source/ui/batch_config.cpp
index 57e132af..68d4dd88 100644
--- a/FreeFileSync/Source/ui/batch_config.cpp
+++ b/FreeFileSync/Source/ui/batch_config.cpp
@@ -130,16 +130,17 @@ void BatchDialog::setConfig(const BatchDialogConfig& dlgCfg)
 
 BatchDialogConfig BatchDialog::getConfig() const
 {
-    BatchDialogConfig dlgCfg = {};
-
-    dlgCfg.ignoreErrors = m_checkBoxIgnoreErrors->GetValue();
-
-    dlgCfg.batchExCfg.batchErrorHandling  = m_radioBtnErrorDialogCancel->GetValue() ? BatchErrorHandling::cancel : BatchErrorHandling::showPopup;
-    dlgCfg.batchExCfg.runMinimized        = m_checkBoxRunMinimized->GetValue();
-    dlgCfg.batchExCfg.autoCloseSummary    = m_checkBoxAutoClose   ->GetValue();
-    dlgCfg.batchExCfg.postSyncAction = getEnumVal(enumPostSyncAction_, *m_choicePostSyncAction);
-
-    return dlgCfg;
+    return
+    {
+        .batchExCfg
+        {
+            .batchErrorHandling  = m_radioBtnErrorDialogCancel->GetValue() ? BatchErrorHandling::cancel : BatchErrorHandling::showPopup,
+            .runMinimized        = m_checkBoxRunMinimized->GetValue(),
+            .autoCloseSummary    = m_checkBoxAutoClose   ->GetValue(),
+            .postSyncAction = getEnumVal(enumPostSyncAction_, *m_choicePostSyncAction),
+        },
+        .ignoreErrors = m_checkBoxIgnoreErrors->GetValue(),
+    };
 }
 
 
diff --git a/FreeFileSync/Source/ui/cfg_grid.cpp b/FreeFileSync/Source/ui/cfg_grid.cpp
index afb631b1..8161d13e 100644
--- a/FreeFileSync/Source/ui/cfg_grid.cpp
+++ b/FreeFileSync/Source/ui/cfg_grid.cpp
@@ -82,9 +82,8 @@ void ConfigView::addCfgFilesImpl(const std::vector<Zstring>& filePaths)
         if (auto it = cfgList_.find(filePath);
             it == cfgList_.end())
         {
-            Details detail = {};
+            Details detail{.lastUseIndex = ++lastUseIndexMax};
             detail.cfgItem.cfgFilePath = filePath;
-            detail.lastUseIndex = ++lastUseIndexMax;
 
             std::tie(detail.name, detail.cfgType, detail.isLastRunCfg) = [&]
             {
diff --git a/FreeFileSync/Source/ui/file_grid.cpp b/FreeFileSync/Source/ui/file_grid.cpp
index 86d2bf28..6c8a1f4a 100644
--- a/FreeFileSync/Source/ui/file_grid.cpp
+++ b/FreeFileSync/Source/ui/file_grid.cpp
@@ -1727,8 +1727,8 @@ public:
             //=> Next keyboard input on left does *not* emit focus change event, but still "scrollMaster" needs to change
             //=> hook keyboard input instead of focus event:
             grid.getMainWin().Bind(wxEVT_CHAR,     handler);
-            grid.getMainWin().Bind(wxEVT_KEY_UP,   handler);
             grid.getMainWin().Bind(wxEVT_KEY_DOWN, handler);
+            //grid.getMainWin().Bind(wxEVT_KEY_UP, handler); -> superfluous?
 
             grid.getMainWin().Bind(wxEVT_LEFT_DOWN,   handler);
             grid.getMainWin().Bind(wxEVT_LEFT_DCLICK, handler);
diff --git a/FreeFileSync/Source/ui/folder_selector.cpp b/FreeFileSync/Source/ui/folder_selector.cpp
index d53fcd8a..1ce778b3 100644
--- a/FreeFileSync/Source/ui/folder_selector.cpp
+++ b/FreeFileSync/Source/ui/folder_selector.cpp
@@ -202,7 +202,7 @@ void FolderSelector::onSelectFolder(wxCommandEvent& event)
     Zstring defaultFolderNative;
     {
         //make sure default folder exists: don't let folder picker hang on non-existing network share!
-        auto folderExistsTimed = [waitEndTime = std::chrono::steady_clock::now() + FOLDER_SELECTED_EXISTENCE_CHECK_TIME_MAX](const AbstractPath& folderPath)
+        auto folderAccessible = [waitEndTime = std::chrono::steady_clock::now() + FOLDER_SELECTED_EXISTENCE_CHECK_TIME_MAX](const AbstractPath& folderPath)
         {
             if (AFS::isNullPath(folderPath))
                 return false;
@@ -223,7 +223,7 @@ void FolderSelector::onSelectFolder(wxCommandEvent& event)
             if (acceptsItemPathPhraseNative(folderPathPhrase)) //noexcept
             {
                 const AbstractPath folderPath = createItemPathNative(folderPathPhrase);
-                if (folderExistsTimed(folderPath))
+                if (folderAccessible(folderPath))
                     if (const Zstring& nativePath = getNativeItemPath(folderPath);
                         !nativePath.empty())
                         defaultFolderNative = nativePath;
diff --git a/FreeFileSync/Source/ui/gui_generated.cpp b/FreeFileSync/Source/ui/gui_generated.cpp
index a30c063c..9ec3baf5 100644
--- a/FreeFileSync/Source/ui/gui_generated.cpp
+++ b/FreeFileSync/Source/ui/gui_generated.cpp
@@ -132,9 +132,9 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     m_panelTopButtons->SetBackgroundColour( wxSystemSettings::GetColour( wxSYS_COLOUR_WINDOW ) );
 
     wxBoxSizer* bSizer1791;
-    bSizer1791 = new wxBoxSizer( wxVERTICAL );
+    bSizer1791 = new wxBoxSizer( wxHORIZONTAL );
 
-    bSizerTopButtons = new wxBoxSizer( wxHORIZONTAL );
+    bSizer2941 = new wxBoxSizer( wxHORIZONTAL );
 
     wxBoxSizer* bSizer261;
     bSizer261 = new wxBoxSizer( wxHORIZONTAL );
@@ -142,14 +142,6 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
 
     bSizer261->Add( 0, 0, 1, 0, 5 );
 
-    m_bpButtonCmpConfig = new wxBitmapButton( m_panelTopButtons, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    m_bpButtonCmpConfig->SetToolTip( _("dummy") );
-
-    bSizer261->Add( m_bpButtonCmpConfig, 0, wxEXPAND, 5 );
-
-
-    bSizer261->Add( 4, 0, 0, 0, 5 );
-
     m_buttonCancel = new wxButton( m_panelTopButtons, wxID_CANCEL, _("Cancel"), wxDefaultPosition, wxSize( -1, -1 ), 0 );
     m_buttonCancel->SetFont( wxFont( wxNORMAL_FONT->GetPointSize(), wxFONTFAMILY_DEFAULT, wxFONTSTYLE_NORMAL, wxFONTWEIGHT_BOLD, false, wxEmptyString ) );
     m_buttonCancel->Enable( false );
@@ -163,6 +155,11 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
 
     bSizer261->Add( m_buttonCompare, 0, wxEXPAND, 5 );
 
+    m_bpButtonCmpConfig = new wxBitmapButton( m_panelTopButtons, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
+    m_bpButtonCmpConfig->SetToolTip( _("dummy") );
+
+    bSizer261->Add( m_bpButtonCmpConfig, 0, wxEXPAND, 5 );
+
     m_bpButtonCmpContext = new wxBitmapButton( m_panelTopButtons, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
     bSizer261->Add( m_bpButtonCmpContext, 0, wxEXPAND, 5 );
 
@@ -170,10 +167,10 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     bSizer261->Add( 0, 0, 1, 0, 5 );
 
 
-    bSizerTopButtons->Add( bSizer261, 1, wxEXPAND, 5 );
+    bSizer2941->Add( bSizer261, 1, wxEXPAND, 5 );
 
 
-    bSizerTopButtons->Add( 5, 2, 0, 0, 5 );
+    bSizer2941->Add( 5, 0, 0, 0, 5 );
 
     wxBoxSizer* bSizer199;
     bSizer199 = new wxBoxSizer( wxHORIZONTAL );
@@ -193,10 +190,10 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     bSizer199->Add( 0, 0, 1, 0, 5 );
 
 
-    bSizerTopButtons->Add( bSizer199, 0, wxEXPAND, 5 );
+    bSizer2941->Add( bSizer199, 0, wxEXPAND, 5 );
 
 
-    bSizerTopButtons->Add( 5, 2, 0, 0, 5 );
+    bSizer2941->Add( 5, 0, 0, 0, 5 );
 
     wxBoxSizer* bSizer262;
     bSizer262 = new wxBoxSizer( wxHORIZONTAL );
@@ -204,20 +201,17 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
 
     bSizer262->Add( 0, 0, 1, 0, 5 );
 
-    m_bpButtonSyncConfig = new wxBitmapButton( m_panelTopButtons, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    m_bpButtonSyncConfig->SetToolTip( _("dummy") );
-
-    bSizer262->Add( m_bpButtonSyncConfig, 0, wxEXPAND, 5 );
-
-
-    bSizer262->Add( 4, 0, 0, 0, 5 );
-
     m_buttonSync = new zen::BitmapTextButton( m_panelTopButtons, wxID_ANY, _("Synchronize"), wxDefaultPosition, wxSize( -1, -1 ), 0 );
     m_buttonSync->SetFont( wxFont( wxNORMAL_FONT->GetPointSize(), wxFONTFAMILY_DEFAULT, wxFONTSTYLE_NORMAL, wxFONTWEIGHT_BOLD, false, wxEmptyString ) );
     m_buttonSync->SetToolTip( _("dummy") );
 
     bSizer262->Add( m_buttonSync, 0, wxEXPAND, 5 );
 
+    m_bpButtonSyncConfig = new wxBitmapButton( m_panelTopButtons, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
+    m_bpButtonSyncConfig->SetToolTip( _("dummy") );
+
+    bSizer262->Add( m_bpButtonSyncConfig, 0, wxEXPAND, 5 );
+
     m_bpButtonSyncContext = new wxBitmapButton( m_panelTopButtons, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
     bSizer262->Add( m_bpButtonSyncContext, 0, wxEXPAND, 5 );
 
@@ -225,10 +219,10 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     bSizer262->Add( 0, 0, 1, 0, 5 );
 
 
-    bSizerTopButtons->Add( bSizer262, 1, wxEXPAND, 5 );
+    bSizer2941->Add( bSizer262, 1, wxEXPAND, 5 );
 
 
-    bSizer1791->Add( bSizerTopButtons, 1, wxEXPAND, 5 );
+    bSizer1791->Add( bSizer2941, 1, wxALIGN_CENTER_VERTICAL, 5 );
 
 
     m_panelTopButtons->SetSizer( bSizer1791 );
@@ -741,7 +735,7 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     m_panelConfig = new wxPanel( this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxTAB_TRAVERSAL );
     m_panelConfig->SetBackgroundColour( wxSystemSettings::GetColour( wxSYS_COLOUR_WINDOW ) );
 
-    bSizerConfig = new wxBoxSizer( wxHORIZONTAL );
+    bSizerConfig = new wxBoxSizer( wxVERTICAL );
 
     bSizerCfgHistoryButtons = new wxBoxSizer( wxHORIZONTAL );
 
@@ -793,21 +787,20 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     wxBoxSizer* bSizer174;
     bSizer174 = new wxBoxSizer( wxVERTICAL );
 
-    wxBoxSizer* bSizer1772;
-    bSizer1772 = new wxBoxSizer( wxHORIZONTAL );
+    bSizerSaveAs = new wxBoxSizer( wxHORIZONTAL );
 
     m_bpButtonSaveAs = new wxBitmapButton( m_panelConfig, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
     m_bpButtonSaveAs->SetToolTip( _("dummy") );
 
-    bSizer1772->Add( m_bpButtonSaveAs, 1, 0, 5 );
+    bSizerSaveAs->Add( m_bpButtonSaveAs, 1, 0, 5 );
 
     m_bpButtonSaveAsBatch = new wxBitmapButton( m_panelConfig, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
     m_bpButtonSaveAsBatch->SetToolTip( _("dummy") );
 
-    bSizer1772->Add( m_bpButtonSaveAsBatch, 1, 0, 5 );
+    bSizerSaveAs->Add( m_bpButtonSaveAsBatch, 1, 0, 5 );
 
 
-    bSizer174->Add( bSizer1772, 0, wxEXPAND, 5 );
+    bSizer174->Add( bSizerSaveAs, 0, wxEXPAND, 5 );
 
     m_staticText97 = new wxStaticText( m_panelConfig, wxID_ANY, _("Save as..."), wxDefaultPosition, wxDefaultSize, 0 );
     m_staticText97->Wrap( -1 );
@@ -817,11 +810,14 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     bSizerCfgHistoryButtons->Add( bSizer174, 0, 0, 5 );
 
 
-    bSizerConfig->Add( bSizerCfgHistoryButtons, 0, wxALIGN_CENTER_HORIZONTAL|wxALIGN_CENTER_VERTICAL, 5 );
+    bSizerConfig->Add( bSizerCfgHistoryButtons, 0, wxALIGN_CENTER_HORIZONTAL, 5 );
 
     m_staticline81 = new wxStaticLine( m_panelConfig, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxLI_HORIZONTAL );
     bSizerConfig->Add( m_staticline81, 0, wxEXPAND|wxTOP, 5 );
 
+
+    bSizerConfig->Add( 10, 0, 0, 0, 5 );
+
     m_gridCfgHistory = new zen::Grid( m_panelConfig, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxHSCROLL|wxVSCROLL );
     m_gridCfgHistory->SetScrollRate( 5, 5 );
     bSizerConfig->Add( m_gridCfgHistory, 1, wxEXPAND, 5 );
@@ -843,62 +839,67 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
 
     bSizerViewFilter->Add( 0, 0, 1, wxEXPAND, 5 );
 
+    bSizerViewButtons = new wxBoxSizer( wxHORIZONTAL );
+
     m_bpButtonViewType = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizerViewFilter->Add( m_bpButtonViewType, 0, wxALIGN_CENTER_HORIZONTAL|wxALIGN_CENTER_VERTICAL|wxRIGHT, 5 );
+    bSizerViewButtons->Add( m_bpButtonViewType, 0, wxALIGN_CENTER_HORIZONTAL|wxALIGN_CENTER_VERTICAL, 5 );
 
-    wxBoxSizer* bSizer300;
-    bSizer300 = new wxBoxSizer( wxHORIZONTAL );
+
+    bSizerViewButtons->Add( 10, 10, 0, 0, 5 );
 
     m_bpButtonShowExcluded = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowExcluded, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL|wxRIGHT, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowExcluded, 0, wxEXPAND, 5 );
+
+
+    bSizerViewButtons->Add( 10, 10, 0, 0, 5 );
 
     m_bpButtonShowDeleteLeft = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowDeleteLeft, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowDeleteLeft, 0, wxEXPAND, 5 );
 
     m_bpButtonShowUpdateLeft = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowUpdateLeft, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowUpdateLeft, 0, wxEXPAND, 5 );
 
     m_bpButtonShowCreateLeft = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowCreateLeft, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowCreateLeft, 0, wxEXPAND, 5 );
 
     m_bpButtonShowLeftOnly = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowLeftOnly, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowLeftOnly, 0, wxEXPAND, 5 );
 
     m_bpButtonShowLeftNewer = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowLeftNewer, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowLeftNewer, 0, wxEXPAND, 5 );
 
     m_bpButtonShowEqual = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowEqual, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowEqual, 0, wxEXPAND, 5 );
 
     m_bpButtonShowDoNothing = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowDoNothing, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowDoNothing, 0, wxEXPAND, 5 );
 
     m_bpButtonShowDifferent = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowDifferent, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowDifferent, 0, wxEXPAND, 5 );
 
     m_bpButtonShowRightNewer = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowRightNewer, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowRightNewer, 0, wxEXPAND, 5 );
 
     m_bpButtonShowRightOnly = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowRightOnly, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowRightOnly, 0, wxEXPAND, 5 );
 
     m_bpButtonShowCreateRight = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowCreateRight, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowCreateRight, 0, wxEXPAND, 5 );
 
     m_bpButtonShowUpdateRight = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowUpdateRight, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowUpdateRight, 0, wxEXPAND, 5 );
 
     m_bpButtonShowDeleteRight = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowDeleteRight, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowDeleteRight, 0, wxEXPAND, 5 );
 
     m_bpButtonShowConflict = new zen::ToggleButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonShowConflict, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
+    bSizerViewButtons->Add( m_bpButtonShowConflict, 0, wxEXPAND, 5 );
 
     m_bpButtonViewFilterContext = new wxBitmapButton( m_panelViewFilter, wxID_ANY, wxNullBitmap, wxDefaultPosition, wxSize( -1, -1 ), wxBU_AUTODRAW|0 );
-    bSizer300->Add( m_bpButtonViewFilterContext, 0, wxEXPAND, 5 );
+    bSizerViewButtons->Add( m_bpButtonViewFilterContext, 0, wxEXPAND, 5 );
 
 
-    bSizerViewFilter->Add( bSizer300, 0, wxALIGN_CENTER_VERTICAL, 5 );
+    bSizerViewFilter->Add( bSizerViewButtons, 0, wxALIGN_CENTER_VERTICAL|wxALIGN_CENTER_HORIZONTAL, 5 );
 
 
     bSizerViewFilter->Add( 0, 0, 1, wxEXPAND, 5 );
@@ -1134,20 +1135,20 @@ MainDialogGenerated::MainDialogGenerated( wxWindow* parent, wxWindowID id, const
     m_menuHelp->Bind(wxEVT_COMMAND_MENU_SELECTED, wxCommandEventHandler( MainDialogGenerated::onMenuCheckVersion ), this, m_menuItemCheckVersionNow->GetId());
     m_menuHelp->Bind(wxEVT_COMMAND_MENU_SELECTED, wxCommandEventHandler( MainDialogGenerated::onMenuCheckVersionAutomatically ), this, m_menuItemCheckVersionAuto->GetId());
     m_menuHelp->Bind(wxEVT_COMMAND_MENU_SELECTED, wxCommandEventHandler( MainDialogGenerated::onMenuAbout ), this, m_menuItemAbout->GetId());
-    m_bpButtonCmpConfig->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onCmpSettings ), NULL, this );
-    m_bpButtonCmpConfig->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onCompSettingsContextMouse ), NULL, this );
     m_buttonCompare->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onCompare ), NULL, this );
     m_buttonCompare->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onCompSettingsContextMouse ), NULL, this );
+    m_bpButtonCmpConfig->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onCmpSettings ), NULL, this );
+    m_bpButtonCmpConfig->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onCompSettingsContextMouse ), NULL, this );
     m_bpButtonCmpContext->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onCompSettingsContext ), NULL, this );
     m_bpButtonCmpContext->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onCompSettingsContextMouse ), NULL, this );
     m_bpButtonFilter->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onConfigureFilter ), NULL, this );
     m_bpButtonFilter->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onGlobalFilterContextMouse ), NULL, this );
     m_bpButtonFilterContext->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onGlobalFilterContext ), NULL, this );
     m_bpButtonFilterContext->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onGlobalFilterContextMouse ), NULL, this );
-    m_bpButtonSyncConfig->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onSyncSettings ), NULL, this );
-    m_bpButtonSyncConfig->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onSyncSettingsContextMouse ), NULL, this );
     m_buttonSync->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onStartSync ), NULL, this );
     m_buttonSync->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onSyncSettingsContextMouse ), NULL, this );
+    m_bpButtonSyncConfig->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onSyncSettings ), NULL, this );
+    m_bpButtonSyncConfig->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onSyncSettingsContextMouse ), NULL, this );
     m_bpButtonSyncContext->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onSyncSettingsContext ), NULL, this );
     m_bpButtonSyncContext->Connect( wxEVT_RIGHT_DOWN, wxMouseEventHandler( MainDialogGenerated::onSyncSettingsContextMouse ), NULL, this );
     m_bpButtonAddPair->Connect( wxEVT_COMMAND_BUTTON_CLICKED, wxCommandEventHandler( MainDialogGenerated::onTopFolderPairAdd ), NULL, this );
@@ -1519,8 +1520,14 @@ ConfigDlgGenerated::ConfigDlgGenerated( wxWindow* parent, wxWindowID id, const w
     m_staticline331 = new wxStaticLine( m_panelComparisonSettings, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxLI_HORIZONTAL );
     bSizer159->Add( m_staticline331, 0, wxEXPAND, 5 );
 
+
+    bSizer159->Add( 0, 0, 1, 0, 5 );
+
     bSizerCompMisc = new wxBoxSizer( wxVERTICAL );
 
+    m_staticline3311 = new wxStaticLine( m_panelComparisonSettings, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxLI_HORIZONTAL );
+    bSizerCompMisc->Add( m_staticline3311, 0, wxEXPAND, 5 );
+
     wxBoxSizer* bSizer2781;
     bSizer2781 = new wxBoxSizer( wxHORIZONTAL );
 
@@ -1568,9 +1575,6 @@ ConfigDlgGenerated::ConfigDlgGenerated( wxWindow* parent, wxWindowID id, const w
 
     bSizerCompMisc->Add( bSizer2781, 0, wxEXPAND, 5 );
 
-    m_staticline3311 = new wxStaticLine( m_panelComparisonSettings, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxLI_HORIZONTAL );
-    bSizerCompMisc->Add( m_staticline3311, 0, wxEXPAND, 5 );
-
 
     bSizer159->Add( bSizerCompMisc, 0, wxEXPAND, 5 );
 
@@ -1651,7 +1655,7 @@ ConfigDlgGenerated::ConfigDlgGenerated( wxWindow* parent, wxWindowID id, const w
     m_panelCompSettingsTab->SetSizer( bSizer275 );
     m_panelCompSettingsTab->Layout();
     bSizer275->Fit( m_panelCompSettingsTab );
-    m_notebook->AddPage( m_panelCompSettingsTab, _("dummy"), false );
+    m_notebook->AddPage( m_panelCompSettingsTab, _("dummy"), true );
     m_panelFilterSettingsTab = new wxPanel( m_notebook, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxTAB_TRAVERSAL );
     m_panelFilterSettingsTab->SetBackgroundColour( wxSystemSettings::GetColour( wxSYS_COLOUR_WINDOW ) );
 
@@ -2489,7 +2493,7 @@ ConfigDlgGenerated::ConfigDlgGenerated( wxWindow* parent, wxWindowID id, const w
     m_panelSyncSettingsTab->SetSizer( bSizer276 );
     m_panelSyncSettingsTab->Layout();
     bSizer276->Fit( m_panelSyncSettingsTab );
-    m_notebook->AddPage( m_panelSyncSettingsTab, _("dummy"), true );
+    m_notebook->AddPage( m_panelSyncSettingsTab, _("dummy"), false );
 
     bSizer190->Add( m_notebook, 1, wxEXPAND|wxTOP|wxRIGHT|wxLEFT, 5 );
 
diff --git a/FreeFileSync/Source/ui/gui_generated.h b/FreeFileSync/Source/ui/gui_generated.h
index 8b47035a..6542e1a8 100644
--- a/FreeFileSync/Source/ui/gui_generated.h
+++ b/FreeFileSync/Source/ui/gui_generated.h
@@ -28,8 +28,8 @@ namespace zen { class BitmapTextButton; }
 #include <wx/font.h>
 #include <wx/colour.h>
 #include <wx/settings.h>
-#include <wx/bmpbuttn.h>
 #include <wx/button.h>
+#include <wx/bmpbuttn.h>
 #include <wx/sizer.h>
 #include <wx/panel.h>
 #include <wx/stattext.h>
@@ -101,15 +101,15 @@ protected:
     wxMenuItem* m_menuItemAbout;
     wxBoxSizer* bSizerPanelHolder;
     wxPanel* m_panelTopButtons;
-    wxBoxSizer* bSizerTopButtons;
-    wxBitmapButton* m_bpButtonCmpConfig;
+    wxBoxSizer* bSizer2941;
     wxButton* m_buttonCancel;
     zen::BitmapTextButton* m_buttonCompare;
+    wxBitmapButton* m_bpButtonCmpConfig;
     wxBitmapButton* m_bpButtonCmpContext;
     wxBitmapButton* m_bpButtonFilter;
     wxBitmapButton* m_bpButtonFilterContext;
-    wxBitmapButton* m_bpButtonSyncConfig;
     zen::BitmapTextButton* m_buttonSync;
+    wxBitmapButton* m_bpButtonSyncConfig;
     wxBitmapButton* m_bpButtonSyncContext;
     wxPanel* m_panelDirectoryPairs;
     wxStaticText* m_staticTextResolvedPathL;
@@ -170,6 +170,7 @@ protected:
     wxStaticText* m_staticText95;
     wxBitmapButton* m_bpButtonSave;
     wxStaticText* m_staticText961;
+    wxBoxSizer* bSizerSaveAs;
     wxBitmapButton* m_bpButtonSaveAs;
     wxBitmapButton* m_bpButtonSaveAsBatch;
     wxStaticText* m_staticText97;
@@ -178,6 +179,7 @@ protected:
     wxPanel* m_panelViewFilter;
     wxBoxSizer* bSizerViewFilter;
     wxBitmapButton* m_bpButtonToggleLog;
+    wxBoxSizer* bSizerViewButtons;
     zen::ToggleButton* m_bpButtonViewType;
     zen::ToggleButton* m_bpButtonShowExcluded;
     zen::ToggleButton* m_bpButtonShowDeleteLeft;
@@ -356,6 +358,7 @@ protected:
     wxHyperlinkCtrl* m_hyperlink241;
     wxStaticLine* m_staticline331;
     wxBoxSizer* bSizerCompMisc;
+    wxStaticLine* m_staticline3311;
     wxStaticBitmap* m_bitmapIgnoreErrors;
     wxCheckBox* m_checkBoxIgnoreErrors;
     wxCheckBox* m_checkBoxAutoRetry;
@@ -364,7 +367,6 @@ protected:
     wxStaticText* m_staticTextAutoRetryDelay;
     wxSpinCtrl* m_spinCtrlAutoRetryCount;
     wxSpinCtrl* m_spinCtrlAutoRetryDelay;
-    wxStaticLine* m_staticline3311;
     wxStaticLine* m_staticline751;
     wxBoxSizer* bSizerPerformance;
     wxPanel* m_panel57;
diff --git a/FreeFileSync/Source/ui/gui_status_handler.cpp b/FreeFileSync/Source/ui/gui_status_handler.cpp
index c6e8470c..7702cb6d 100644
--- a/FreeFileSync/Source/ui/gui_status_handler.cpp
+++ b/FreeFileSync/Source/ui/gui_status_handler.cpp
@@ -328,10 +328,7 @@ void StatusHandlerTemporaryPanel::onLocalKeyEvent(wxKeyEvent& event)
 {
     const int keyCode = event.GetKeyCode();
     if (keyCode == WXK_ESCAPE)
-    {
-        wxCommandEvent dummy;
-        onAbortCompare(dummy);
-    }
+        return userRequestAbort();
 
     event.Skip();
 }
diff --git a/FreeFileSync/Source/ui/log_panel.cpp b/FreeFileSync/Source/ui/log_panel.cpp
index aa686a8a..261b2085 100644
--- a/FreeFileSync/Source/ui/log_panel.cpp
+++ b/FreeFileSync/Source/ui/log_panel.cpp
@@ -468,62 +468,58 @@ void LogPanel::onGridButtonEvent(wxKeyEvent& event)
 
 void LogPanel::onLocalKeyEvent(wxKeyEvent& event) //process key events without explicit menu entry :)
 {
-    if (processingKeyEventHandler_) //avoid recursion
+    if (!processingKeyEventHandler_) //avoid recursion
     {
-        event.Skip();
-        return;
-    }
-    processingKeyEventHandler_ = true;
-    ZEN_ON_SCOPE_EXIT(processingKeyEventHandler_ = false);
-
-
-    const int keyCode = event.GetKeyCode();
+        processingKeyEventHandler_ = true;
+        ZEN_ON_SCOPE_EXIT(processingKeyEventHandler_ = false);
 
-    if (event.ControlDown())
-        switch (keyCode)
-        {
-            case 'A':
-                m_gridMessages->SetFocus();
-                m_gridMessages->selectAllRows(GridEventPolicy::allow);
-                return; // -> swallow event! don't allow default grid commands!
+        const int keyCode = event.GetKeyCode();
 
-                //case 'C': -> already implemented by "Grid" class
-        }
-    else
-        switch (keyCode)
-        {
-            //redirect certain (unhandled) keys directly to grid!
-            case WXK_UP:
-            case WXK_DOWN:
-            case WXK_LEFT:
-            case WXK_RIGHT:
-            case WXK_PAGEUP:
-            case WXK_PAGEDOWN:
-            case WXK_HOME:
-            case WXK_END:
-
-            case WXK_NUMPAD_UP:
-            case WXK_NUMPAD_DOWN:
-            case WXK_NUMPAD_LEFT:
-            case WXK_NUMPAD_RIGHT:
-            case WXK_NUMPAD_PAGEUP:
-            case WXK_NUMPAD_PAGEDOWN:
-            case WXK_NUMPAD_HOME:
-            case WXK_NUMPAD_END:
-                if (!isComponentOf(wxWindow::FindFocus(), m_gridMessages) && //don't propagate keyboard commands if grid is already in focus
-                    m_gridMessages->IsEnabled())
-                    if (wxEvtHandler* evtHandler = m_gridMessages->getMainWin().GetEventHandler())
-                    {
-                        m_gridMessages->SetFocus();
+        if (event.ControlDown())
+            switch (keyCode)
+            {
+                case 'A':
+                    m_gridMessages->SetFocus();
+                    m_gridMessages->selectAllRows(GridEventPolicy::allow);
+                    return; // -> swallow event! don't allow default grid commands!
 
-                        event.SetEventType(wxEVT_KEY_DOWN); //the grid event handler doesn't expect wxEVT_CHAR_HOOK!
-                        evtHandler->ProcessEvent(event); //propagating event catched at wxTheApp to child leads to recursion, but we prevented it...
-                        event.Skip(false); //definitively handled now!
-                        return;
-                    }
-                break;
-        }
+                    //case 'C': -> already implemented by "Grid" class
+            }
+        else
+            switch (keyCode)
+            {
+                //redirect certain (unhandled) keys directly to grid!
+                case WXK_UP:
+                case WXK_DOWN:
+                case WXK_LEFT:
+                case WXK_RIGHT:
+                case WXK_PAGEUP:
+                case WXK_PAGEDOWN:
+                case WXK_HOME:
+                case WXK_END:
+
+                case WXK_NUMPAD_UP:
+                case WXK_NUMPAD_DOWN:
+                case WXK_NUMPAD_LEFT:
+                case WXK_NUMPAD_RIGHT:
+                case WXK_NUMPAD_PAGEUP:
+                case WXK_NUMPAD_PAGEDOWN:
+                case WXK_NUMPAD_HOME:
+                case WXK_NUMPAD_END:
+                    if (!isComponentOf(wxWindow::FindFocus(), m_gridMessages) && //don't propagate keyboard commands if grid is already in focus
+                        m_gridMessages->IsEnabled())
+                        if (wxEvtHandler* evtHandler = m_gridMessages->getMainWin().GetEventHandler())
+                        {
+                            m_gridMessages->SetFocus();
 
+                            event.SetEventType(wxEVT_KEY_DOWN); //the grid event handler doesn't expect wxEVT_CHAR_HOOK!
+                            evtHandler->ProcessEvent(event); //propagating event catched at wxTheApp to child leads to recursion, but we prevented it...
+                            event.Skip(false); //definitively handled now!
+                            return;
+                        }
+                    break;
+            }
+    }
     event.Skip();
 }
 
diff --git a/FreeFileSync/Source/ui/main_dlg.cpp b/FreeFileSync/Source/ui/main_dlg.cpp
index 2896d639..beea4555 100644
--- a/FreeFileSync/Source/ui/main_dlg.cpp
+++ b/FreeFileSync/Source/ui/main_dlg.cpp
@@ -313,7 +313,7 @@ void updateTopButton(wxBitmapButton& btn, const wxImage& img, const wxString& va
              stackImages(btnIconImg, btnImg, ImageStackLayout::horizontal, ImageStackAlignment::center, fastFromDIP(5)) :
              stackImages(btnImg, btnIconImg, ImageStackLayout::horizontal, ImageStackAlignment::center, fastFromDIP(5));
 
-    wxSize btnSize = btnImg.GetSize() + wxSize(fastFromDIP(10), fastFromDIP(10)); //add border space
+    wxSize btnSize = btnImg.GetSize();
     btnSize.x = std::max(btnSize.x, fastFromDIP(TOP_BUTTON_OPTIMAL_WIDTH_DIP));
 
     btnImg = resizeCanvas(btnImg, btnSize, wxALIGN_CENTER);
@@ -411,6 +411,7 @@ void MainDialog::create(const Zstring& globalConfigFilePath,
                         const std::vector<Zstring>& referenceFiles,
                         bool startComparison)
 {
+
     const XmlGlobalSettings globSett = globalSettings ? *globalSettings : tryLoadGlobalConfig(globalConfigFilePath);
 
     try
@@ -675,7 +676,10 @@ imgFileManagerSmall_([]
 
     auiMgr_.AddPane(m_panelTopButtons,
                     wxAuiPaneInfo().Name(L"TopPanel").Layer(2).Top().Row(1).Caption(_("Main Bar")).CaptionVisible(false).
-                    PaneBorder(false).Gripper().MinSize(fastFromDIP(TOP_BUTTON_OPTIMAL_WIDTH_DIP), m_panelTopButtons->GetSize().GetHeight()));
+                    PaneBorder(false).Gripper().
+                    //BestSize(-1, m_panelTopButtons->GetSize().GetHeight() + fastFromDIP(10)).
+                    MinSize(fastFromDIP(TOP_BUTTON_OPTIMAL_WIDTH_DIP), m_panelTopButtons->GetSize().GetHeight())
+                   );
     //note: min height is calculated incorrectly by wxAuiManager if panes with and without caption are in the same row => use smaller min-size
 
     auiMgr_.AddPane(compareStatus_->getAsWindow(),
@@ -704,7 +708,7 @@ imgFileManagerSmall_([]
     m_panelViewFilter->GetSizer()->SetSizeHints(m_panelViewFilter); //~=Fit() + SetMinSize()
     auiMgr_.AddPane(m_panelViewFilter,
                     wxAuiPaneInfo().Name(L"ViewFilterPanel").Layer(2).Bottom().Row(1).Caption(_("View Settings")).CaptionVisible(false).
-                    PaneBorder(false).Gripper().MinSize(fastFromDIP(100), m_panelViewFilter->GetSize().y));
+                    PaneBorder(false).Gripper().MinSize(fastFromDIP(80), m_panelViewFilter->GetSize().y));
 
     m_panelConfig->GetSizer()->SetSizeHints(m_panelConfig); //~=Fit() + SetMinSize()
     auiMgr_.AddPane(m_panelConfig,
@@ -854,8 +858,7 @@ imgFileManagerSmall_([]
     {
         m_menuTools->Bind(wxEVT_COMMAND_MENU_SELECTED, [this, panelWindow](wxCommandEvent&)
         {
-            wxAuiPaneInfo& paneInfo = this->auiMgr_.GetPane(panelWindow);
-            paneInfo.Show();
+            this->auiMgr_.GetPane(panelWindow).Show();
             this->auiMgr_.Update();
         }, menuItem->GetId());
 
@@ -1921,40 +1924,46 @@ void MainDialog::enableGuiElements()
 }
 
 
-namespace
-{
-void updateSizerOrientation(wxBoxSizer& sizer, wxWindow& window, double horizontalWeight)
-{
-    const int newOrientation = window.GetSize().GetWidth() * horizontalWeight > window.GetSize().GetHeight() ? wxHORIZONTAL : wxVERTICAL; //check window NOT sizer width!
-    if (sizer.GetOrientation() != newOrientation)
-    {
-        sizer.SetOrientation(newOrientation);
-        window.Layout();
-    }
-}
-}
-
-
 void MainDialog::onResizeTopButtonPanel(wxEvent& event)
 {
-    updateSizerOrientation(*bSizerTopButtons, *m_panelTopButtons, 0.5);
+    //TODO: shrink icons when out of space!?
     event.Skip();
 }
 
 
 void MainDialog::onResizeConfigPanel(wxEvent& event)
 {
-    updateSizerOrientation(*bSizerConfig, *m_panelConfig, 0.5);
+    const double horizontalWeight = 0.75;
+    const int newOrientation = m_panelConfig->GetSize().GetWidth() * horizontalWeight >
+                               m_panelConfig->GetSize().GetHeight() ? wxHORIZONTAL : wxVERTICAL; //check window NOT sizer width!
+    if (bSizerConfig->GetOrientation() != newOrientation)
+    {
+        //hide button labels for horizontal layout
+        for (wxSizerItem* szItem : bSizerCfgHistoryButtons->GetChildren())
+            if (auto sizerChild = dynamic_cast<wxBoxSizer*>(szItem->GetSizer()))
+                for (wxSizerItem* szItem2 : sizerChild->GetChildren())
+                    if (auto btnLabel = dynamic_cast<wxStaticText*>(szItem2->GetWindow()))
+                        btnLabel->Show(newOrientation == wxVERTICAL);
+
+        bSizerConfig->SetOrientation(newOrientation);
+        bSizerCfgHistoryButtons->SetOrientation(newOrientation == wxHORIZONTAL ? wxVERTICAL : wxHORIZONTAL);
+        bSizerSaveAs           ->SetOrientation(newOrientation == wxHORIZONTAL ? wxVERTICAL : wxHORIZONTAL);
+        m_panelConfig->Layout();
+    }
     event.Skip();
 }
 
 
 void MainDialog::onResizeViewPanel(wxEvent& event)
 {
-    //we need something more fancy for the statistics:
-    const int newOrientation = m_panelViewFilter->GetSize().GetWidth() > m_panelViewFilter->GetSize().GetHeight() ? wxHORIZONTAL : wxVERTICAL; //check window NOT sizer width!
+    const int newOrientation = m_panelViewFilter->GetSize().GetWidth() >
+                               m_panelViewFilter->GetSize().GetHeight() ? wxHORIZONTAL : wxVERTICAL; //check window NOT sizer width!
     if (bSizerViewFilter->GetOrientation() != newOrientation)
     {
+        bSizerStatistics->SetOrientation(newOrientation);
+        bSizerViewButtons->SetOrientation(newOrientation);
+        bSizerViewFilter->SetOrientation(newOrientation);
+
         //apply opposite orientation for child sizers
         const int childOrient = newOrientation == wxHORIZONTAL ? wxVERTICAL : wxHORIZONTAL;
 
@@ -1963,8 +1972,6 @@ void MainDialog::onResizeViewPanel(wxEvent& event)
                 if (sizerChild->GetOrientation() != childOrient)
                     sizerChild->SetOrientation(childOrient);
 
-        bSizerStatistics->SetOrientation(newOrientation);
-        bSizerViewFilter->SetOrientation(newOrientation);
         m_panelViewFilter->Layout();
         m_panelStatistics->Layout();
     }
@@ -2146,119 +2153,115 @@ void MainDialog::onGridKeyEvent(wxKeyEvent& event, Grid& grid, bool leftSide)
 
 void MainDialog::onLocalKeyEvent(wxKeyEvent& event) //process key events without explicit menu entry :)
 {
-    if (!localKeyEventsEnabled_)
+    if (localKeyEventsEnabled_) //avoid recursion
     {
-        event.Skip();
-        return;
-    }
-    localKeyEventsEnabled_ = false; //avoid recursion
-    ZEN_ON_SCOPE_EXIT(localKeyEventsEnabled_ = true);
+        localKeyEventsEnabled_ = false; //avoid recursion
+        ZEN_ON_SCOPE_EXIT(localKeyEventsEnabled_ = true);
 
+        const int keyCode = event.GetKeyCode();
 
-    const int keyCode = event.GetKeyCode();
+        //CTRL + X
+        /*   if (event.ControlDown())
+                switch (keyCode)
+                {
+                    case 'F': //CTRL + F
+                        showFindPanel();
+                        return; //-> swallow event!
+                }                                      */
 
-    //CTRL + X
-    /*   if (event.ControlDown())
+        if (event.ControlDown())
             switch (keyCode)
             {
-                case 'F': //CTRL + F
-                    showFindPanel();
+                case WXK_TAB: //CTRL + TAB
+                case WXK_NUMPAD_TAB: //don't use F10: avoid accidental clicks: https://freefilesync.org/forum/viewtopic.php?t=1663
+                    swapSides();
                     return; //-> swallow event!
-            }                                      */
+            }
 
-    if (event.ControlDown())
         switch (keyCode)
         {
-            case WXK_TAB: //CTRL + TAB
-            case WXK_NUMPAD_TAB: //don't use F10: avoid accidental clicks: https://freefilesync.org/forum/viewtopic.php?t=1663
-                swapSides();
+            case WXK_F3:
+            case WXK_NUMPAD_F3:
+                startFindNext(!event.ShiftDown() /*searchAscending*/);
                 return; //-> swallow event!
-        }
 
-    switch (keyCode)
-    {
-        case WXK_F3:
-        case WXK_NUMPAD_F3:
-            startFindNext(!event.ShiftDown() /*searchAscending*/);
-            return; //-> swallow event!
-
-        //case WXK_F6:
-        //{
-        //    wxCommandEvent dummy2(wxEVT_COMMAND_BUTTON_CLICKED);
-        //    m_bpButtonCmpConfig->Command(dummy2); //simulate click
-        //}
-        //return; //-> swallow event!
-
-        //case WXK_F7:
-        //{
-        //    wxCommandEvent dummy2(wxEVT_COMMAND_BUTTON_CLICKED);
-        //    m_bpButtonFilter->Command(dummy2); //simulate click
-        //}
-        //return; //-> swallow event!
-
-        //case WXK_F8:
-        //{
-        //    wxCommandEvent dummy2(wxEVT_COMMAND_BUTTON_CLICKED);
-        //    m_bpButtonSyncConfig->Command(dummy2); //simulate click
-        //}
-        //return; //-> swallow event!
-
-        case WXK_F11:
-            warn_static("F11 not working at all on macOS!")
-            setGridViewType(m_bpButtonViewType->isActive() ? GridViewType::difference : GridViewType::action);
-            return; //-> swallow event!
-
-        //redirect certain (unhandled) keys directly to grid!
-        case WXK_UP:
-        case WXK_DOWN:
-        case WXK_LEFT:
-        case WXK_RIGHT:
-        case WXK_PAGEUP:
-        case WXK_PAGEDOWN:
-        case WXK_HOME:
-        case WXK_END:
-
-        case WXK_NUMPAD_UP:
-        case WXK_NUMPAD_DOWN:
-        case WXK_NUMPAD_LEFT:
-        case WXK_NUMPAD_RIGHT:
-        case WXK_NUMPAD_PAGEUP:
-        case WXK_NUMPAD_PAGEDOWN:
-        case WXK_NUMPAD_HOME:
-        case WXK_NUMPAD_END:
-        {
-            const wxWindow* focus = wxWindow::FindFocus();
-            if (!isComponentOf(focus, m_gridMainL     ) && //
-                !isComponentOf(focus, m_gridMainC     ) && //don't propagate keyboard commands if grid is already in focus
-                !isComponentOf(focus, m_gridMainR     ) && //
-                !isComponentOf(focus, m_gridOverview  ) &&
-                !isComponentOf(focus, m_gridCfgHistory) && //don't propagate if selecting config
-                !isComponentOf(focus, m_panelSearch   ) &&
-                !isComponentOf(focus, m_panelLog      ) &&
-                !isComponentOf(focus, m_panelDirectoryPairs) && //don't propagate if changing directory fields
-                m_gridMainL->IsEnabled())
-                if (wxEvtHandler* evtHandler = m_gridMainL->getMainWin().GetEventHandler())
-                {
-                    m_gridMainL->SetFocus();
+            //case WXK_F6:
+            //{
+            //    wxCommandEvent dummy2(wxEVT_COMMAND_BUTTON_CLICKED);
+            //    m_bpButtonCmpConfig->Command(dummy2); //simulate click
+            //}
+            //return; //-> swallow event!
+
+            //case WXK_F7:
+            //{
+            //    wxCommandEvent dummy2(wxEVT_COMMAND_BUTTON_CLICKED);
+            //    m_bpButtonFilter->Command(dummy2); //simulate click
+            //}
+            //return; //-> swallow event!
+
+            //case WXK_F8:
+            //{
+            //    wxCommandEvent dummy2(wxEVT_COMMAND_BUTTON_CLICKED);
+            //    m_bpButtonSyncConfig->Command(dummy2); //simulate click
+            //}
+            //return; //-> swallow event!
+
+            case WXK_F11:
+                warn_static("F11 not working at all on macOS!")
+                setGridViewType(m_bpButtonViewType->isActive() ? GridViewType::difference : GridViewType::action);
+                return; //-> swallow event!
 
-                    event.SetEventType(wxEVT_KEY_DOWN); //the grid event handler doesn't expect wxEVT_CHAR_HOOK!
-                    evtHandler->ProcessEvent(event); //propagating event to child lead to recursion with old key_event.h handling => still an issue?
-                    event.Skip(false); //definitively handled now!
-                    return;
-                }
-        }
-        break;
+            //redirect certain (unhandled) keys directly to grid!
+            case WXK_UP:
+            case WXK_DOWN:
+            case WXK_LEFT:
+            case WXK_RIGHT:
+            case WXK_PAGEUP:
+            case WXK_PAGEDOWN:
+            case WXK_HOME:
+            case WXK_END:
 
-        case WXK_ESCAPE: //let's do something useful and hide the log panel
-            if (!isComponentOf(wxWindow::FindFocus(), m_panelSearch)  && //search panel also handles ESC!
-                m_panelLog->IsEnabled())
+            case WXK_NUMPAD_UP:
+            case WXK_NUMPAD_DOWN:
+            case WXK_NUMPAD_LEFT:
+            case WXK_NUMPAD_RIGHT:
+            case WXK_NUMPAD_PAGEUP:
+            case WXK_NUMPAD_PAGEDOWN:
+            case WXK_NUMPAD_HOME:
+            case WXK_NUMPAD_END:
             {
-                if (auiMgr_.GetPane(m_panelLog).IsShown()) //else: let it "ding"
-                    return showLogPanel(false /*show*/);
+                const wxWindow* focus = wxWindow::FindFocus();
+                if (!isComponentOf(focus, m_gridMainL     ) && //
+                    !isComponentOf(focus, m_gridMainC     ) && //don't propagate keyboard commands if grid is already in focus
+                    !isComponentOf(focus, m_gridMainR     ) && //
+                    !isComponentOf(focus, m_gridOverview  ) &&
+                    !isComponentOf(focus, m_gridCfgHistory) && //don't propagate if selecting config
+                    !isComponentOf(focus, m_panelSearch   ) &&
+                    !isComponentOf(focus, m_panelLog      ) &&
+                    !isComponentOf(focus, m_panelDirectoryPairs) && //don't propagate if changing directory fields
+                    m_gridMainL->IsEnabled())
+                    if (wxEvtHandler* evtHandler = m_gridMainL->getMainWin().GetEventHandler())
+                    {
+                        m_gridMainL->SetFocus();
+
+                        event.SetEventType(wxEVT_KEY_DOWN); //the grid event handler doesn't expect wxEVT_CHAR_HOOK!
+                        evtHandler->ProcessEvent(event); //propagating event to child lead to recursion with old key_event.h handling => still an issue?
+                        event.Skip(false); //definitively handled now!
+                        return;
+                    }
             }
             break;
-    }
 
+            case WXK_ESCAPE: //let's do something useful and hide the log panel
+                if (!isComponentOf(wxWindow::FindFocus(), m_panelSearch)  && //search panel also handles ESC!
+                    m_panelLog->IsEnabled())
+                {
+                    if (auiMgr_.GetPane(m_panelLog).IsShown()) //else: let it "ding"
+                        return showLogPanel(false /*show*/);
+                }
+                break;
+        }
+    }
     event.Skip();
 }
 
@@ -2778,9 +2781,9 @@ void MainDialog::onGridLabelContextRim(GridLabelClickEvent& event, bool leftSide
     {
         menu.addRadio(label, [sz, &setIconSize] { setIconSize(sz, true /*showIcons*/); }, globalCfg_.mainDlg.iconSize == sz, globalCfg_.mainDlg.showIcons);
     };
-    addSizeEntry(L"    " + _("Small" ), GridIconSize::small );
-    addSizeEntry(L"    " + _("Medium"), GridIconSize::medium);
-    addSizeEntry(L"    " + _("Large" ), GridIconSize::large );
+    addSizeEntry(TAB_SPACE + _("Small" ), GridIconSize::small );
+    addSizeEntry(TAB_SPACE + _("Medium"), GridIconSize::medium);
+    addSizeEntry(TAB_SPACE + _("Large" ), GridIconSize::large );
 
     //----------------------------------------------------------------------------------------------
     auto setDefault = [&]
@@ -3074,27 +3077,15 @@ void MainDialog::onConfigSave(wxCommandEvent& event)
     if (activeCfgFilePath.empty())
         trySaveConfig(nullptr);
     else
-        try
-        {
-            switch (getXmlType(activeCfgFilePath)) //throw FileError
-            {
-                case XmlType::gui:
-                    trySaveConfig(&activeCfgFilePath);
-                    break;
-                case XmlType::batch:
-                    trySaveBatchConfig(&activeCfgFilePath);
-                    break;
-                case XmlType::global:
-                case XmlType::other:
-                    showNotificationDialog(this, DialogInfoType::error,
-                                           PopupDialogCfg().setDetailInstructions(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(activeCfgFilePath))));
-                    break;
-            }
-        }
-        catch (const FileError& e)
-        {
-            showNotificationDialog(this, DialogInfoType::error, PopupDialogCfg().setDetailInstructions(e.toString()));
-        }
+    {
+        if (endsWithAsciiNoCase(activeCfgFilePath, Zstr(".ffs_gui")))
+            trySaveConfig(&activeCfgFilePath);
+        else if (endsWithAsciiNoCase(activeCfgFilePath, Zstr(".ffs_batch")))
+            trySaveBatchConfig(&activeCfgFilePath);
+        else
+            showNotificationDialog(this, DialogInfoType::error,
+                                   PopupDialogCfg().setDetailInstructions(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(activeCfgFilePath))));
+    }
 }
 
 
@@ -3105,7 +3096,7 @@ bool MainDialog::trySaveConfig(const Zstring* guiCfgPath) //"false": error/cance
     if (guiCfgPath)
     {
         cfgFilePath = *guiCfgPath;
-        assert(endsWith(cfgFilePath, Zstr(".ffs_gui")));
+        assert(endsWithAsciiNoCase(cfgFilePath, Zstr(".ffs_gui")));
     }
     else
     {
@@ -3127,7 +3118,12 @@ bool MainDialog::trySaveConfig(const Zstring* guiCfgPath) //"false": error/cance
                                   wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
         if (fileSelector.ShowModal() != wxID_OK)
             return false;
-        cfgFilePath = globalCfg_.mainDlg.config.lastSelectedFile = utfTo<Zstring>(fileSelector.GetPath());
+
+        cfgFilePath = utfTo<Zstring>(fileSelector.GetPath());
+        if (!endsWithAsciiNoCase(cfgFilePath, Zstr(".ffs_gui"))) //no weird shit!
+            cfgFilePath += Zstr(".ffs_gui");          //https://freefilesync.org/forum/viewtopic.php?t=9451#p34724
+
+        globalCfg_.mainDlg.config.lastSelectedFile = cfgFilePath;
     }
 
     const XmlGuiConfig guiCfg = getConfig();
@@ -3161,15 +3157,12 @@ bool MainDialog::trySaveBatchConfig(const Zstring* batchCfgPath) //"false": erro
         Zstring referenceBatchFile;
         if (batchCfgPath)
             referenceBatchFile = *batchCfgPath;
-        else if (!activeCfgFilePath.empty())
-            if (getXmlType(activeCfgFilePath) == XmlType::batch) //throw FileError
-                referenceBatchFile = activeCfgFilePath;
+        else if (!activeCfgFilePath.empty() && endsWithAsciiNoCase(activeCfgFilePath, Zstr(".ffs_batch")))
+            referenceBatchFile = activeCfgFilePath;
 
         if (!referenceBatchFile.empty())
-        {
             batchExCfg = readBatchConfig(referenceBatchFile).first.batchExCfg; //throw FileError
-            //=> ignore warnings altogether: user has seen them already when loading the config file!
-        }
+        //=> ignore warnings altogether: user has seen them already when loading the config file!
     }
     catch (const FileError& e)
     {
@@ -3181,7 +3174,7 @@ bool MainDialog::trySaveBatchConfig(const Zstring* batchCfgPath) //"false": erro
     if (batchCfgPath)
     {
         cfgFilePath = *batchCfgPath;
-        assert(endsWith(cfgFilePath, Zstr(".ffs_batch")));
+        assert(endsWithAsciiNoCase(cfgFilePath, Zstr(".ffs_batch")));
     }
     else
     {
@@ -3208,7 +3201,12 @@ bool MainDialog::trySaveBatchConfig(const Zstring* batchCfgPath) //"false": erro
                                   wxFD_SAVE | wxFD_OVERWRITE_PROMPT);
         if (fileSelector.ShowModal() != wxID_OK)
             return false;
-        cfgFilePath = globalCfg_.mainDlg.config.lastSelectedFile = utfTo<Zstring>(fileSelector.GetPath());
+
+        cfgFilePath = utfTo<Zstring>(fileSelector.GetPath());
+        if (!endsWithAsciiNoCase(cfgFilePath, Zstr(".ffs_batch"))) //no weird shit!
+            cfgFilePath += Zstr(".ffs_batch");          //https://freefilesync.org/forum/viewtopic.php?t=9451#p34724
+
+        globalCfg_.mainDlg.config.lastSelectedFile = cfgFilePath;
     }
 
     const XmlGuiConfig guiCfg = getConfig();
@@ -3252,24 +3250,14 @@ bool MainDialog::saveOldConfig() //"false": error/cancel
                                            _("&Save"), _("Do&n't save")))
                 {
                     case QuestionButton2::yes: //save
-                        try
-                        {
-                            switch (getXmlType(activeCfgFilePath)) //throw FileError
-                            {
-                                case XmlType::gui:
-                                    return trySaveConfig(&activeCfgFilePath); //"false": error/cancel
-                                case XmlType::batch:
-                                    return trySaveBatchConfig(&activeCfgFilePath); //"false": error/cancel
-                                case XmlType::global:
-                                case XmlType::other:
-                                    showNotificationDialog(this, DialogInfoType::error,
-                                                           PopupDialogCfg().setDetailInstructions(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(activeCfgFilePath))));
-                                    return false;
-                            }
-                        }
-                        catch (const FileError& e)
+                        if (endsWithAsciiNoCase(activeCfgFilePath, Zstr(".ffs_gui")))
+                            return trySaveConfig(&activeCfgFilePath); //"false": error/cancel
+                        else if (endsWithAsciiNoCase(activeCfgFilePath, Zstr(".ffs_batch")))
+                            return trySaveBatchConfig(&activeCfgFilePath); //"false": error/cancel
+                        else
                         {
-                            showNotificationDialog(this, DialogInfoType::error, PopupDialogCfg().setDetailInstructions(e.toString()));
+                            showNotificationDialog(this, DialogInfoType::error,
+                                                   PopupDialogCfg().setDetailInstructions(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtPath(activeCfgFilePath))));
                             return false;
                         }
                         break;
@@ -4249,7 +4237,7 @@ void MainDialog::updateGui()
             //*INDENT-ON*
         }
 
-    updateTopButton(*m_buttonCompare, loadImage("compare"),   getVariantName(cmpVar),  cmpVarIconName, false /*makeGrey*/);
+    updateTopButton(*m_buttonCompare, loadImage("compare"),    getVariantName(cmpVar),  cmpVarIconName, false /*makeGrey*/);
     updateTopButton(*m_buttonSync,    loadImage("start_sync"), getVariantName(syncVar), syncVarIconName, folderCmp_.empty());
     m_panelTopButtons->Layout();
 
diff --git a/FreeFileSync/Source/ui/progress_indicator.cpp b/FreeFileSync/Source/ui/progress_indicator.cpp
index 3ad876ac..58125051 100644
--- a/FreeFileSync/Source/ui/progress_indicator.cpp
+++ b/FreeFileSync/Source/ui/progress_indicator.cpp
@@ -944,7 +944,6 @@ void SyncProgressDialogImpl<TopLevelDialog>::onLocalKeyEvent(wxKeyEvent& event)
             activeButton.Command(dummy); //simulate click
             return;
         }
-        break;
     }
 
     event.Skip();
@@ -1645,7 +1644,6 @@ void SyncProgressDialogImpl<TopLevelDialog>::resumeFromSystray(bool userRequeste
         updateStaticGui();                        //restore Windows 7 task bar status   (e.g. required in pause mode)
         updateProgressGui(false  /*allowYield*/); //restore Windows 7 task bar progress (e.g. required in pause mode)
 
-
         if (userRequested)
         {
             if (parentFrame_)
diff --git a/FreeFileSync/Source/ui/progress_indicator.h b/FreeFileSync/Source/ui/progress_indicator.h
index 28b050ec..a8536df7 100644
--- a/FreeFileSync/Source/ui/progress_indicator.h
+++ b/FreeFileSync/Source/ui/progress_indicator.h
@@ -9,11 +9,8 @@
 
 #include <functional>
 #include <zen/error_log.h>
-//#include <zen/zstring.h>
 #include <wx/frame.h>
-//#include "../config.h"
 #include "../status_handler.h"
-//#include "../return_codes.h"
 
 
 namespace fff
diff --git a/FreeFileSync/Source/ui/search_grid.cpp b/FreeFileSync/Source/ui/search_grid.cpp
index d26eb40e..cff99d12 100644
--- a/FreeFileSync/Source/ui/search_grid.cpp
+++ b/FreeFileSync/Source/ui/search_grid.cpp
@@ -16,10 +16,10 @@ using namespace fff;
 namespace
 {
 template <bool respectCase>
-void normalizeForSeach(std::wstring& str);
+void normalizeForSearch(std::wstring& str);
 
 template <> inline
-void normalizeForSeach<true /*respectCase*/>(std::wstring& str)
+void normalizeForSearch<true /*respectCase*/>(std::wstring& str)
 {
     for (wchar_t& c : str)
         if (!isAsciiChar(c))
@@ -33,7 +33,7 @@ void normalizeForSeach<true /*respectCase*/>(std::wstring& str)
 }
 
 template <> inline
-void normalizeForSeach<false /*respectCase*/>(std::wstring& str)
+void normalizeForSearch<false /*respectCase*/>(std::wstring& str)
 {
     for (wchar_t& c : str)
         if (!isAsciiChar(c))
@@ -53,14 +53,14 @@ template <bool respectCase>
 class MatchFound
 {
 public:
-    MatchFound(const std::wstring& textToFind) : textToFind_(textToFind)
+    explicit MatchFound(const std::wstring& textToFind) : textToFind_(textToFind)
     {
-        normalizeForSeach<respectCase>(textToFind_);
+        normalizeForSearch<respectCase>(textToFind_);
     }
 
     bool operator()(std::wstring&& phrase) const
     {
-        normalizeForSeach<respectCase>(phrase);
+        normalizeForSearch<respectCase>(phrase);
         return contains(phrase, textToFind_);
     }
 
diff --git a/FreeFileSync/Source/ui/sync_cfg.cpp b/FreeFileSync/Source/ui/sync_cfg.cpp
index 72915145..14f78eb8 100644
--- a/FreeFileSync/Source/ui/sync_cfg.cpp
+++ b/FreeFileSync/Source/ui/sync_cfg.cpp
@@ -15,7 +15,6 @@
 #include <wx+/choice_enum.h>
 #include <wx+/image_tools.h>
 #include <wx+/font_size.h>
-//#include <wx+/std_button_layout.h>
 #include <wx+/popup_dlg.h>
 #include <wx+/image_resources.h>
 #include <wx+/window_tools.h>
@@ -25,7 +24,6 @@
 #include "../base/norm_filter.h"
 #include "../base/file_hierarchy.h"
 #include "../base/icon_loader.h"
-//#include "../log_file.h"
 #include "../afs/concrete.h"
 #include "../base_tools.h"
 
@@ -38,6 +36,7 @@ using namespace fff;
 namespace
 {
 const int CFG_DESCRIPTION_WIDTH_DIP = 230;
+const wchar_t arrowRight[] = L"\u2192"; //"RIGHTWARDS ARROW"
 
 
 void initBitmapRadioButtons(const std::vector<std::pair<ToggleButton*, std::string /*imgName*/>>& buttons, bool alignLeft)
@@ -90,6 +89,113 @@ void initBitmapRadioButtons(const std::vector<std::pair<ToggleButton*, std::stri
     }
 }
 
+
+bool sanitizeFilter(FilterConfig& filterCfg, const std::vector<std::wstring>& folderDisplayPaths, wxWindow* parent)
+{
+    //include filter must not be empty!
+    if (trimCpy(filterCfg.includeFilter).empty())
+        filterCfg.includeFilter = FilterConfig().includeFilter; //no need to show error message, just correct user input
+
+
+    //replace full paths by relative ones: frequent user error => help out: https://freefilesync.org/forum/viewtopic.php?t=9225
+    auto normalizeForSearch = [](Zstring str)
+    {
+        //1. ignore Unicode normalization form 2. ignore case 3. normalize path separator
+        str = getUpperCase(str); //getUnicodeNormalForm() is implied by getUpperCase()
+
+        if constexpr (FILE_NAME_SEPARATOR != Zstr('/' )) std::replace(str.begin(), str.end(), Zstr('/'),  FILE_NAME_SEPARATOR);
+        if constexpr (FILE_NAME_SEPARATOR != Zstr('\\')) std::replace(str.begin(), str.end(), Zstr('\\'), FILE_NAME_SEPARATOR);
+
+        return str;
+    };
+
+    std::vector<Zstring> folderPathsPf; //normalized + postfix path separator
+    {
+        const Zstring includeFilterNorm = normalizeForSearch(filterCfg.includeFilter);
+        const Zstring excludeFilterNorm = normalizeForSearch(filterCfg.excludeFilter);
+
+        for (const std::wstring& displayPath : folderDisplayPaths)
+            if (!displayPath.empty())
+                if (const Zstring pathNormPf = appendSeparator(normalizeForSearch(utfTo<Zstring>(displayPath)));
+                    contains(includeFilterNorm, pathNormPf) || //perf!?
+                    contains(excludeFilterNorm, pathNormPf))   //
+                    folderPathsPf.push_back(pathNormPf);
+
+        removeDuplicates(folderPathsPf);
+    }
+
+    if (!folderPathsPf.empty())
+    {
+        std::vector<std::pair<Zstring /*from*/, Zstring /*to*/>> replacements;
+
+        auto replaceFullPaths = [&](Zstring& filterPhrase)
+        {
+            Zstring filterPhraseNew;
+            const Zchar* itFilterOrig = filterPhrase.begin();
+
+            split2(filterPhrase, [](Zchar c) { return c == FILTER_ITEM_SEPARATOR || c == Zstr('\n'); }, //delimiters
+            [&](const Zchar* blockFirst, const Zchar* blockLast)
+            {
+                std::tie(blockFirst, blockLast) = trimCpy(blockFirst, blockLast, true /*fromLeft*/, true /*fromRight*/, [](Zchar c) { return isWhiteSpace(c); });
+                if (blockFirst != blockLast)
+                {
+                    const Zstring phrase{blockFirst, blockLast};
+
+                    for (const Zstring& pathNormPf : folderPathsPf)
+                        if (startsWith(normalizeForSearch(phrase), pathNormPf))
+                        {
+                            //emulate a "normalized afterFirst()":
+                            ptrdiff_t sepCount = std::count(pathNormPf.begin(), pathNormPf.end(), FILE_NAME_SEPARATOR);
+                            assert(sepCount > 0);
+
+                            for (auto it = phrase.begin(); it != phrase.end(); ++it)
+                                if (*it == Zstr('/') ||
+                                    *it == Zstr('\\'))
+                                    if (--sepCount == 0)
+                                    {
+                                        const Zstring relPath(it, phrase.end()); //include first path separator
+
+                                        filterPhraseNew.append(itFilterOrig, blockFirst);
+                                        filterPhraseNew += relPath;
+                                        itFilterOrig = blockLast;
+
+                                        replacements.emplace_back(phrase, relPath);
+                                        return; //... to next block
+                                    }
+                            throw std::logic_error("Contract violation! " + std::string(__FILE__) + ':' + numberTo<std::string>(__LINE__));
+                        }
+                }
+            });
+            filterPhraseNew.append(itFilterOrig, filterPhrase.cend());
+
+            filterPhrase = filterPhraseNew;
+        };
+        replaceFullPaths(filterCfg.includeFilter);
+        replaceFullPaths(filterCfg.excludeFilter);
+
+        assert(!replacements.empty());
+        if (!replacements.empty())
+        {
+            std::wstring detailsMsg;
+            for (const auto& [from, to] : replacements)
+                detailsMsg += utfTo<std::wstring>(from) + L' ' + arrowRight + L' ' + utfTo<std::wstring>(to) + L'\n';
+            detailsMsg.pop_back();
+
+            switch (showConfirmationDialog(parent, DialogInfoType::info, PopupDialogCfg().
+                                           setMainInstructions(_("Each filter item must be a path relative to the base folders. The following changes are suggested:")).
+                                           setDetailInstructions(detailsMsg), _("&Change")))
+            {
+                case ConfirmationButton::accept: //change
+                    break;
+
+                case ConfirmationButton::cancel:
+                    return false;
+            }
+        }
+    }
+    return true;
+}
+
 //==========================================================================
 
 class ConfigDialog : public ConfigDlgGenerated
@@ -256,6 +362,9 @@ private:
     GlobalPairConfig globalPairCfg_;
     std::vector<LocalPairConfig> localPairCfg_;
 
+    //display paths to fix filter if user pastes full folder paths
+    std::vector<std::wstring> folderDisplayPaths_;
+
     int selectedPairIndexToShow_ = EMPTY_PAIR_INDEX_SELECTED;
     static const int EMPTY_PAIR_INDEX_SELECTED = -2;
 
@@ -537,12 +646,18 @@ globalLogFolderPhrase_(globalLogFolderPhrase)
     m_listBoxFolderPair->Append(_("All folder pairs"));
     for (const LocalPairConfig& lpc : localPairCfg)
     {
-        std::wstring fpName = getShortDisplayNameForFolderPair(createAbstractPath(lpc.folderPathPhraseLeft ),
-                                                               createAbstractPath(lpc.folderPathPhraseRight));
+        const AbstractPath folderPathL= createAbstractPath(lpc.folderPathPhraseLeft);
+        const AbstractPath folderPathR= createAbstractPath(lpc.folderPathPhraseRight);
+
+        std::wstring fpName = getShortDisplayNameForFolderPair(folderPathL, folderPathR);
         if (trimCpy(fpName).empty())
             fpName = L"<" + _("empty") + L">";
 
-        m_listBoxFolderPair->Append(L"     " + fpName);
+        m_listBoxFolderPair->Append(TAB_SPACE + fpName);
+
+        //collect display paths for filter correction
+        if (!AFS::isNullPath(folderPathL)) folderDisplayPaths_.push_back(AFS::getDisplayPath(folderPathL));
+        if (!AFS::isNullPath(folderPathR)) folderDisplayPaths_.push_back(AFS::getDisplayPath(folderPathR));
     }
 
     if (!showMultipleCfgs)
@@ -553,13 +668,13 @@ globalLogFolderPhrase_(globalLogFolderPhrase)
 
     //temporarily set main config as reference for window height calculations:
     globalPairCfg_ = GlobalPairConfig();
-    globalPairCfg_.syncCfg.directionCfg.var = SyncVariant::mirror;        //
+    globalPairCfg_.syncCfg.directionCfg.var = SyncVariant::mirror;            //
     globalPairCfg_.syncCfg.handleDeletion   = DeletionPolicy::versioning;     //
     globalPairCfg_.syncCfg.versioningFolderPhrase = Zstr("dummy");            //set tentatively for sync dir height calculation below
     globalPairCfg_.syncCfg.versioningStyle  = VersioningStyle::timestampFile; //
     globalPairCfg_.syncCfg.versionMaxAgeDays = 30;                            //
     globalPairCfg_.miscCfg.altLogFolderPathPhrase = Zstr("dummy");            //
-    globalPairCfg_.miscCfg.emailNotifyAddress     =      "dummy";            //
+    globalPairCfg_.miscCfg.emailNotifyAddress     =      "dummy";             //
 
     selectFolderPairConfig(-1);
 
@@ -705,7 +820,7 @@ std::optional<CompConfig> ConfigDialog::getCompConfig() const
 
     CompConfig compCfg;
     compCfg.compareVar = localCmpVar_;
-    compCfg.handleSymlinks = !m_checkBoxSymlinksInclude->GetValue() ? SymLinkHandling::exclude : m_radioBtnSymlinksDirect->GetValue() ? SymLinkHandling::direct : SymLinkHandling::follow;
+    compCfg.handleSymlinks = !m_checkBoxSymlinksInclude->GetValue() ? SymLinkHandling::exclude : m_radioBtnSymlinksDirect->GetValue() ? SymLinkHandling::asLink : SymLinkHandling::follow;
     compCfg.ignoreTimeShiftMinutes = fromTimeShiftPhrase(copyStringTo<std::wstring>(m_textCtrlTimeShift->GetValue()));
 
     return compCfg;
@@ -731,7 +846,7 @@ void ConfigDialog::setCompConfig(const CompConfig* compCfg)
             m_checkBoxSymlinksInclude->SetValue(true);
             m_radioBtnSymlinksFollow->SetValue(true);
             break;
-        case SymLinkHandling::direct:
+        case SymLinkHandling::asLink:
             m_checkBoxSymlinksInclude->SetValue(true);
             m_radioBtnSymlinksDirect->SetValue(true);
             break;
@@ -1497,7 +1612,7 @@ void ConfigDialog::selectFolderPairConfig(int newPairIndexToShow)
     }
     else
     {
-        setCompConfig(get(localPairCfg_[selectedPairIndexToShow_].localCmpCfg ));
+        setCompConfig(get(localPairCfg_[selectedPairIndexToShow_].localCmpCfg));
         setSyncConfig(get(localPairCfg_[selectedPairIndexToShow_].localSyncCfg));
         setFilterConfig  (localPairCfg_[selectedPairIndexToShow_].localFilter);
     }
@@ -1508,9 +1623,9 @@ bool ConfigDialog::unselectFolderPairConfig(bool validateParams)
 {
     assert(selectedPairIndexToShow_ == -1 ||  makeUnsigned(selectedPairIndexToShow_) < localPairCfg_.size());
 
-    std::optional<CompConfig> compCfg   = getCompConfig();
-    std::optional<SyncConfig> syncCfg   = getSyncConfig();
-    FilterConfig              filterCfg = getFilterConfig();
+    std::optional<CompConfig> compCfg =   getCompConfig();
+    std::optional<SyncConfig> syncCfg =   getSyncConfig();
+    FilterConfig            filterCfg = getFilterConfig();
 
     std::optional<MiscSyncConfig> miscCfg;
     if (selectedPairIndexToShow_ < 0)
@@ -1519,9 +1634,13 @@ bool ConfigDialog::unselectFolderPairConfig(bool validateParams)
     //------- parameter validation (BEFORE writing output!) -------
     if (validateParams)
     {
-        //parameter correction: include filter must not be empty!
-        if (trimCpy(filterCfg.includeFilter).empty())
-            filterCfg.includeFilter = FilterConfig().includeFilter; //no need to show error message, just correct user input
+        //parameter validation and correction:
+        if (!sanitizeFilter(filterCfg, folderDisplayPaths_, this))
+        {
+            m_notebook->ChangeSelection(static_cast<size_t>(SyncConfigPanel::filter));
+            m_textCtrlExclude->SetFocus();
+            return false;
+        }
 
         if (syncCfg && syncCfg->handleDeletion == DeletionPolicy::versioning)
         {
diff --git a/FreeFileSync/Source/ui/version_check.cpp b/FreeFileSync/Source/ui/version_check.cpp
index c51507f0..3e4f80cb 100644
--- a/FreeFileSync/Source/ui/version_check.cpp
+++ b/FreeFileSync/Source/ui/version_check.cpp
@@ -68,6 +68,12 @@ time_t getVersionCheckCurrentTime()
     time_t now = std::time(nullptr);
     return now;
 }
+
+
+void openBrowserForDownload(wxWindow* parent)
+{
+    wxLaunchDefaultBrowser(L"https://freefilesync.org/get_latest.php");
+}
 }
 
 
@@ -126,7 +132,7 @@ std::vector<std::pair<std::string, std::string>> geHttpPostParameters(wxWindow&
     const OsVersion osv = getOsVersion();
     params.emplace_back("os_version", numberTo<std::string>(osv.major) + "." + numberTo<std::string>(osv.minor));
 
-    const char* osArch = BuildArch::program == BuildArch::bit32 ? "32" : "64";
+    const char* osArch = cpuArchName;
     params.emplace_back("os_arch", osArch);
 
 #if GTK_MAJOR_VERSION == 2
@@ -137,6 +143,17 @@ std::vector<std::pair<std::string, std::string>> geHttpPostParameters(wxWindow&
 #error unknown GTK version!
 #endif
 
+    const std::string ffsLang = []
+    {
+        const wxLanguage lang = getLanguage();
+
+        for (const TranslationInfo& ti : getAvailableTranslations())
+            if (ti.languageID == lang)
+                return ti.locale;
+        return std::string("zz");
+    }();
+    params.emplace_back("ffs_lang",  ffsLang);
+
     params.emplace_back("language", utfTo<std::string>(getIso639Language()));
     params.emplace_back("country",  utfTo<std::string>(getIso3166Country()));
 
@@ -157,7 +174,6 @@ void showUpdateAvailableDialog(wxWindow* parent, const std::string& onlineVersio
     catch (const SysError& e) { updateDetailsMsg = _("Failed to retrieve update information.") + + L"\n\n" + e.toString(); }
 
 
-    std::function<void()> openBrowserForDownload = [] { wxLaunchDefaultBrowser(L"https://freefilesync.org/get_latest.php"); };
     switch (showConfirmationDialog(parent, DialogInfoType::info, PopupDialogCfg().
                                    setIcon(loadImage("FreeFileSync", fastFromDIP(48))).
                                    setTitle(_("Check for Program Updates")).
@@ -250,7 +266,7 @@ void fff::checkForUpdateNow(wxWindow& parent, std::string& lastOnlineVersion)
                                            setDetailInstructions(e.toString()), _("&Check"), _("&Retry")))
             {
                 case ConfirmationButton2::accept:
-                    wxLaunchDefaultBrowser(L"https://freefilesync.org/get_latest.php");
+                    openBrowserForDownload(&parent);
                     break;
                 case ConfirmationButton2::accept2: //retry
                     checkForUpdateNow(parent, lastOnlineVersion); //note: retry via recursion!!!
@@ -350,7 +366,7 @@ void fff::automaticUpdateCheckEval(wxWindow& parent, time_t& lastUpdateCheck, st
                                            _("&Check"), _("&Retry")))
             {
                 case ConfirmationButton2::accept:
-                    wxLaunchDefaultBrowser(L"https://freefilesync.org/get_latest.php");
+                    openBrowserForDownload(&parent);
                     break;
                 case ConfirmationButton2::accept2: //retry
                     automaticUpdateCheckEval(parent, lastUpdateCheck, lastOnlineVersion,
diff --git a/FreeFileSync/Source/version/version.h b/FreeFileSync/Source/version/version.h
index cebf68d0..eea2ae14 100644
--- a/FreeFileSync/Source/version/version.h
+++ b/FreeFileSync/Source/version/version.h
@@ -3,7 +3,7 @@
 
 namespace fff
 {
-const char ffsVersion[] = "11.23"; //internal linkage!
+const char ffsVersion[] = "11.24"; //internal linkage!
 const char FFS_VERSION_SEPARATOR = '.';
 }
 
diff --git a/wx+/dc.h b/wx+/dc.h
index e22820a7..48d0fe72 100644
--- a/wx+/dc.h
+++ b/wx+/dc.h
@@ -136,7 +136,7 @@ wxBitmap toScaledBitmap(const wxImage& img /*expected to be DPI-scaled!*/)
 
 
 //all this shit just because wxDC::SetScaleFactor() is missing:
-inline 
+inline
 void setScaleFactor(wxDC& dc, double scale)
 {
     struct wxDcSurgeon : public wxDCImpl
diff --git a/wx+/graph.cpp b/wx+/graph.cpp
index eb9256f4..f9094386 100644
--- a/wx+/graph.cpp
+++ b/wx+/graph.cpp
@@ -232,7 +232,7 @@ void drawCornerText(wxDC& dc, const wxRect& graphArea, const wxString& txt, Grap
 
 //calculate intersection of polygon with half-plane
 template <class Function, class Function2>
-void cutPoints(std::vector<CurvePoint>& curvePoints, std::vector<char>& oobMarker, Function isInside, Function2 getIntersection, bool doPolygonCut)
+void cutPoints(std::vector<CurvePoint>& curvePoints, std::vector<unsigned char>& oobMarker, Function isInside, Function2 getIntersection, bool doPolygonCut)
 {
     assert(curvePoints.size() == oobMarker.size());
 
@@ -240,8 +240,8 @@ void cutPoints(std::vector<CurvePoint>& curvePoints, std::vector<char>& oobMarke
 
     auto isMarkedOob = [&](size_t index) { return oobMarker[index] != 0; }; //test if point is start of an OOB line
 
-    std::vector<CurvePoint> curvePointsTmp;
-    std::vector<char>       oobMarkerTmp;
+    std::vector<CurvePoint>    curvePointsTmp;
+    std::vector<unsigned char> oobMarkerTmp;
     curvePointsTmp.reserve(curvePoints.size()); //allocating memory for these containers is one
     oobMarkerTmp  .reserve(oobMarker  .size()); //of the more expensive operations of Graph2D!
 
@@ -308,13 +308,13 @@ private:
     const double y_;
 };
 
-void cutPointsOutsideX(std::vector<CurvePoint>& curvePoints, std::vector<char>& oobMarker, double minX, double maxX, bool doPolygonCut)
+void cutPointsOutsideX(std::vector<CurvePoint>& curvePoints, std::vector<unsigned char>& oobMarker, double minX, double maxX, bool doPolygonCut)
 {
     cutPoints(curvePoints, oobMarker, [&](const CurvePoint& pt) { return pt.x >= minX; }, GetIntersectionX(minX), doPolygonCut);
     cutPoints(curvePoints, oobMarker, [&](const CurvePoint& pt) { return pt.x <= maxX; }, GetIntersectionX(maxX), doPolygonCut);
 }
 
-void cutPointsOutsideY(std::vector<CurvePoint>& curvePoints, std::vector<char>& oobMarker, double minY, double maxY, bool doPolygonCut)
+void cutPointsOutsideY(std::vector<CurvePoint>& curvePoints, std::vector<unsigned char>& oobMarker, double minY, double maxY, bool doPolygonCut)
 {
     cutPoints(curvePoints, oobMarker, [&](const CurvePoint& pt) { return pt.y >= minY; }, GetIntersectionY(minY), doPolygonCut);
     cutPoints(curvePoints, oobMarker, [&](const CurvePoint& pt) { return pt.y <= maxY; }, GetIntersectionY(maxY), doPolygonCut);
@@ -615,8 +615,8 @@ void Graph2D::render(wxDC& dc) const
         double minY = attr_.minY ? *attr_.minY :  std::numeric_limits<double>::infinity(); //automatic: ensure values are initialized by first curve
         double maxY = attr_.maxY ? *attr_.maxY : -std::numeric_limits<double>::infinity(); //
 
-        std::vector<std::vector<CurvePoint>> curvePoints(curves_.size());
-        std::vector<std::vector<char>>       oobMarker  (curves_.size()); //effectively a std::vector<bool> marking points that start an out-of-bounds line
+        std::vector<std::vector<CurvePoint>>    curvePoints(curves_.size());
+        std::vector<std::vector<unsigned char>> oobMarker  (curves_.size()); //effectively a std::vector<bool> marking points that start an out-of-bounds line
 
         for (size_t index = 0; index < curves_.size(); ++index)
         {
diff --git a/wx+/grid.cpp b/wx+/grid.cpp
index a32de84e..5d2adc1a 100644
--- a/wx+/grid.cpp
+++ b/wx+/grid.cpp
@@ -164,7 +164,7 @@ void GridData::drawCellText(wxDC& dc, const wxRect& rect, const std::wstring& te
 
     if (extentTrunc.GetWidth() > rect.width)
     {
-        //unlike Windows Explorer, we truncate UTF-16 correctly: e.g. CJK-Ideogramm encodes to TWO wchar_t: utfTo<std::wstring>("\xf0\xa4\xbd\x9c");
+        //unlike Windows Explorer, we truncate UTF-16 correctly: e.g. CJK-Ideograph encodes to TWO wchar_t: utfTo<std::wstring>("\xf0\xa4\xbd\x9c");
         size_t low  = 0;                   //number of unicode chars!
         size_t high = unicodeLength(text); //
         if (high > 1)
@@ -285,7 +285,7 @@ public:
         Bind(wxEVT_MOUSE_CAPTURE_LOST, [this](wxMouseCaptureLostEvent& event) { onMouseCaptureLost(event); });
 
         Bind(wxEVT_KEY_DOWN, [this](wxKeyEvent& event) { onKeyDown(event); });
-        Bind(wxEVT_KEY_UP,   [this](wxKeyEvent& event) { onKeyUp  (event); });
+        //Bind(wxEVT_KEY_UP,   [this](wxKeyEvent& event) { onKeyUp  (event); }); -> superfluous?
 
         assert(GetClientAreaOrigin() == wxPoint()); //generally assumed when dealing with coordinates below
     }
@@ -340,12 +340,6 @@ private:
             event.Skip();
     }
 
-    void onKeyUp(wxKeyEvent& event)
-    {
-        if (!sendEventToParent(event)) //let parent collect all key events
-            event.Skip();
-    }
-
     void onMouseWheel(wxMouseEvent& event)
     {
         /*  MSDN, WM_MOUSEWHEEL: "Sent to the focus window when the mouse wheel is rotated.
@@ -969,6 +963,17 @@ public:
         colLabelWin_(colLabelWin)
     {
         Bind(EVENT_GRID_HAS_SCROLLED, [this](wxCommandEvent& event) { onRequestWindowUpdate(event); });
+
+        Bind(wxEVT_KEY_DOWN, [this](wxKeyEvent& event)
+        {
+            if (event.GetKeyCode() == WXK_ESCAPE && activeSelection_) //allow Escape key to cancel active selection!
+            {
+                wxMouseCaptureLostEvent evt;
+                GetEventHandler()->ProcessEvent(evt); //better integrate into event handling rather than calling onMouseCaptureLost() directly!?
+            }
+            else
+                event.Skip();
+        });
     }
 
     ~MainWin() { assert(!gridUpdatePending_); }
@@ -1099,6 +1104,13 @@ private:
 
     void onMouseDown(wxMouseEvent& event) //handle left and right mouse button clicks (almost) the same
     {
+        if (activeSelection_) //allow other mouse button to cancel active selection!
+        {
+            wxMouseCaptureLostEvent evt;
+            GetEventHandler()->ProcessEvent(evt);
+            return;
+        }
+
         if (auto prov = refParent().getDataProvider())
         {
             evalMouseMovement(event.GetPosition()); //update highlight in obscure cases (e.g. right-click while other context menu is open)
diff --git a/wx+/grid.h b/wx+/grid.h
index 867abf35..3b3e76b7 100644
--- a/wx+/grid.h
+++ b/wx+/grid.h
@@ -10,7 +10,6 @@
 #include <memory>
 #include <numeric>
 #include <optional>
-//#include <set>
 #include <vector>
 #include <zen/stl_tools.h>
 #include <wx/scrolwin.h>
diff --git a/wx+/image_resources.cpp b/wx+/image_resources.cpp
index 36055f3f..58ae4d25 100644
--- a/wx+/image_resources.cpp
+++ b/wx+/image_resources.cpp
@@ -70,7 +70,7 @@ ImageHolder xbrzScale(int width, int height, const unsigned char* imageRgb, cons
 }
 
 
-auto getScalerTask(const std::string& imageName, const wxImage& img, int hqScale, Protected<std::vector<std::pair<std::string, ImageHolder>>>& result)
+auto createScalerTask(const std::string& imageName, const wxImage& img, int hqScale, Protected<std::vector<std::pair<std::string, ImageHolder>>>& result)
 {
     assert(runningOnMainThread());
     return [imageName,
@@ -97,7 +97,7 @@ public:
     {
         assert(runningOnMainThread());
         imgKeeper_.push_back(img); //retain (ref-counted) wxImage so that the rgb/alpha pointers remain valid after passed to threads
-        threadGroup_->run(getScalerTask(imageName, img, hqScale_, result_));
+        threadGroup_->run(createScalerTask(imageName, img, hqScale_, result_));
     }
 
     std::unordered_map<std::string, wxImage> waitAndGetResult()
@@ -125,7 +125,7 @@ private:
     std::vector<wxImage> imgKeeper_;
     Protected<std::vector<std::pair<std::string, ImageHolder>>> result_;
 
-    using TaskType = FunctionReturnTypeT<decltype(&getScalerTask)>;
+    using TaskType = FunctionReturnTypeT<decltype(&createScalerTask)>;
     std::optional<ThreadGroup<TaskType>> threadGroup_{ThreadGroup<TaskType>(std::max<int>(std::thread::hardware_concurrency(), 1), Zstr("xBRZ Scaler"))};
     //hardware_concurrency() == 0 if "not computable or well defined"
 };
@@ -192,11 +192,13 @@ ImageBuffer::ImageBuffer(const Zstring& zipPath) //throw FileError
             else
                 assert(false);
     }
-    catch (FileError&) //fall back to folder
+    catch (FileError&) //fall back to folder: dev build (only!?)
     {
         const Zstring fallbackFolder = beforeLast(zipPath, Zstr(".zip"), IfNotFoundReturn::none);
-        if (dirAvailable(fallbackFolder)) //Debug build (only!?)
-            traverseFolder(fallbackFolder, [&](const FileInfo& fi)
+        if (!itemStillExists(fallbackFolder)) //throw FileError
+            throw;
+
+        traverseFolder(fallbackFolder, [&](const FileInfo& fi)
         {
             if (endsWith(fi.fullPath, Zstr(".png")))
             {
@@ -204,8 +206,6 @@ ImageBuffer::ImageBuffer(const Zstring& zipPath) //throw FileError
                 streams.emplace_back(fi.itemName, std::move(stream));
             }
         }, nullptr, nullptr, [](const std::wstring& errorMsg) { throw FileError(errorMsg); });
-        else
-            throw;
     }
     //--------------------------------------------------------------------
 
diff --git a/wx+/no_flicker.h b/wx+/no_flicker.h
index d8f2d6cd..7fa4ae23 100644
--- a/wx+/no_flicker.h
+++ b/wx+/no_flicker.h
@@ -85,20 +85,26 @@ void setTextWithUrls(wxRichTextCtrl& richCtrl, const wxString& newText)
     urlStyle.SetTextColour(*wxBLUE);
     urlStyle.SetFontUnderlined(true);
 
-    for (const auto& [type, text] : blocks)
+    for (auto& [type, text] : blocks)
         switch (type)
         {
             case BlockType::text:
+                if (endsWith(text, L"\n\n")) //bug: multiple newlines before a URL are condensed to only one;
+                    //Why? fuck knows why! no such issue with double newlines *after* URL => hack this shit
+                    text.RemoveLast().Append(ZERO_WIDTH_SPACE).Append(L'\n');
+
                 richCtrl.WriteText(text);
                 break;
 
             case BlockType::url:
+            {
                 richCtrl.BeginStyle(urlStyle);
                 ZEN_ON_SCOPE_EXIT(richCtrl.EndStyle());
                 richCtrl.BeginURL(text);
                 ZEN_ON_SCOPE_EXIT(richCtrl.EndURL());
                 richCtrl.WriteText(text);
-                break;
+            }
+            break;
         }
 
     if (std::any_of(blocks.begin(), blocks.end(), [](const auto& item) { return item.first == BlockType::url; }))
diff --git a/wx+/popup_dlg.cpp b/wx+/popup_dlg.cpp
index 0a4c75c0..dfa5494f 100644
--- a/wx+/popup_dlg.cpp
+++ b/wx+/popup_dlg.cpp
@@ -10,6 +10,7 @@
 #include <wx/app.h>
 #include <wx/display.h>
 #include <wx/sound.h>
+#include "app_main.h"
 #include "bitmap_button.h"
 #include "no_flicker.h"
 #include "font_size.h"
diff --git a/wx+/rtl.h b/wx+/rtl.h
index 42af52e1..80a75671 100644
--- a/wx+/rtl.h
+++ b/wx+/rtl.h
@@ -66,22 +66,22 @@ void drawBitmapRtlMirror(wxDC& dc, const wxImage& img, const wxRect& rect, int a
 
         case wxLayout_RightToLeft:
             if (rect.GetWidth() > 0 && rect.GetHeight() > 0)
-        {
-            if (!buffer || buffer->GetSize() != rect.GetSize()) //[!] since we do a mirror, width needs to match exactly!
-                buffer.emplace(rect.GetSize());
+            {
+                if (!buffer || buffer->GetSize() != rect.GetSize()) //[!] since we do a mirror, width needs to match exactly!
+                    buffer.emplace(rect.GetSize());
 
-            if (buffer->GetScaleFactor() != dc.GetContentScaleFactor()) //needed here?
-                buffer->SetScaleFactor(dc.GetContentScaleFactor());     //
+                if (buffer->GetScaleFactor() != dc.GetContentScaleFactor()) //needed here?
+                    buffer->SetScaleFactor(dc.GetContentScaleFactor());     //
 
-            wxMemoryDC memDc(*buffer); //copies scale factor from wxBitmap
-            memDc.Blit(wxPoint(0, 0), rect.GetSize(), &dc, rect.GetTopLeft()); //blit in: background is mirrored due to memDc, dc having different layout direction!
+                wxMemoryDC memDc(*buffer); //copies scale factor from wxBitmap
+                memDc.Blit(wxPoint(0, 0), rect.GetSize(), &dc, rect.GetTopLeft()); //blit in: background is mirrored due to memDc, dc having different layout direction!
 
-            impl::drawBitmapAligned(memDc, img, wxRect(0, 0, rect.width, rect.height), alignment);
-            //note: we cannot simply use memDc.SetLayoutDirection(wxLayout_RightToLeft) due to some strange 1 pixel bug! 2022-04-04: maybe fixed in wxWidgets 3.1.6?
+                impl::drawBitmapAligned(memDc, img, wxRect(0, 0, rect.width, rect.height), alignment);
+                //note: we cannot simply use memDc.SetLayoutDirection(wxLayout_RightToLeft) due to some strange 1 pixel bug! 2022-04-04: maybe fixed in wxWidgets 3.1.6?
 
-            dc.Blit(rect.GetTopLeft(), rect.GetSize(), &memDc, wxPoint(0, 0)); //blit out: mirror once again
-        }
-        break;
+                dc.Blit(rect.GetTopLeft(), rect.GetSize(), &memDc, wxPoint(0, 0)); //blit out: mirror once again
+            }
+            break;
 
         case wxLayout_Default: //CAVEAT: wxPaintDC/wxMemoryDC on wxGTK/wxMAC does not implement SetLayoutDirection()!!! => GetLayoutDirection() == wxLayout_Default
             if (wxTheApp->GetLayoutDirection() == wxLayout_RightToLeft)
diff --git a/xBRZ/src/xbrz.cpp b/xBRZ/src/xbrz.cpp
index 65dfc47e..448a4b74 100644
--- a/xBRZ/src/xbrz.cpp
+++ b/xBRZ/src/xbrz.cpp
@@ -283,20 +283,18 @@ template <class ColorDistance>
 FORCE_INLINE //detect blend direction
 BlendResult preProcessCorners(const Kernel_4x4& ker, const xbrz::ScalerCfg& cfg) //result: E, F, H, I corners of "GradientType"
 {
-
-    BlendResult result = {};
-
     if ((ker.e == ker.f &&
          ker.h == ker.i) ||
         (ker.e == ker.h &&
          ker.f == ker.i))
-        return result;
+        return {};
 
     auto dist = [&](uint32_t pix1, uint32_t pix2) { return ColorDistance::dist(pix1, pix2, cfg.testAttribute); };
 
     const double hf = dist(ker.g, ker.e) + dist(ker.e, ker.c) + dist(ker.k, ker.i) + dist(ker.i, ker.o) + cfg.centerDirectionBias * dist(ker.h, ker.f);
     const double ei = dist(ker.d, ker.h) + dist(ker.h, ker.l) + dist(ker.b, ker.f) + dist(ker.f, ker.n) + cfg.centerDirectionBias * dist(ker.e, ker.i);
 
+    BlendResult result = {};
     if (hf < ei) //test sample: 70% of values max(hf, ei) / min(hf, ei) are between 1.1 and 3.7 with median being 1.8
     {
         const bool dominantGradient = cfg.dominantDirectionThreshold * hf < ei;
diff --git a/zen/build_info.h b/zen/build_info.h
index b06c1302..86ff303c 100644
--- a/zen/build_info.h
+++ b/zen/build_info.h
@@ -26,6 +26,7 @@ enum class BuildArch
 static_assert((BuildArch::program == BuildArch::bit32 ? 32 : 64) == sizeof(void*) * 8);
 
 
+//harmonize with os_arch enum in update_checks table:
 constexpr const char* cpuArchName = BuildArch::program == BuildArch::bit32 ? "i686": "x86-64";
 
 }
diff --git a/zen/file_access.cpp b/zen/file_access.cpp
index 6a62f671..2e119e87 100644
--- a/zen/file_access.cpp
+++ b/zen/file_access.cpp
@@ -70,7 +70,7 @@ std::optional<ItemType> zen::itemStillExists(const Zstring& itemPath) //throw Fi
             try
             {
                 traverseFolder(*parentPath,
-                [&](const    FileInfo& fi) { if (fi.itemName == itemName) throw ItemType::file;    },
+                [&](const    FileInfo& fi) { if (fi.itemName == itemName) throw ItemType::file;    }, //case-sensitive! itemPath must be normalized!
                 [&](const  FolderInfo& fi) { if (fi.itemName == itemName) throw ItemType::folder;  },
                 [&](const SymlinkInfo& si) { if (si.itemName == itemName) throw ItemType::symlink; },
                 [](const std::wstring& errorMsg) { throw FileError(errorMsg); });
@@ -233,7 +233,6 @@ void zen::removeDirectoryPlainRecursion(const Zstring& dirPath) //throw FileErro
 
 namespace
 {
-
 /* Usage overview: (avoid circular pattern!)
 
   moveAndRenameItem() --> moveAndRenameFileSub()
@@ -319,18 +318,20 @@ void setWriteTimeNative(const Zstring& itemPath, const timespec& modTime, ProcSy
             => utimens: https://github.com/coreutils/gnulib/blob/master/lib/utimens.c
         touch: https://github.com/coreutils/coreutils/blob/master/src/touch.c
             => fdutimensat: https://github.com/coreutils/gnulib/blob/master/lib/fdutimensat.c                  */
-    timespec newTimes[2] = {};
-    newTimes[0].tv_sec = ::time(nullptr); //access time; don't use UTIME_NOW/UTIME_OMIT: more bugs! https://freefilesync.org/forum/viewtopic.php?t=1701
-    newTimes[1] = modTime; //modification time
+    const timespec newTimes[2]
+    {
+        {.tv_sec = ::time(nullptr)}, //access time; don't use UTIME_NOW/UTIME_OMIT: more bugs! https://freefilesync.org/forum/viewtopic.php?t=1701
+        modTime,
+    };
     //test: even modTime == 0 is correctly applied (no NOOP!) test2: same behavior for "utime()"
 
     //hell knows why files on gvfs-mounted Samba shares fail to open(O_WRONLY) returning EOPNOTSUPP:
     //https://freefilesync.org/forum/viewtopic.php?t=2803 => utimensat() works (but not for gvfs SFTP)
-    if (::utimensat(AT_FDCWD, itemPath.c_str(), newTimes, procSl == ProcSymlink::direct ? AT_SYMLINK_NOFOLLOW : 0) == 0)
+    if (::utimensat(AT_FDCWD, itemPath.c_str(), newTimes, procSl == ProcSymlink::asLink ? AT_SYMLINK_NOFOLLOW : 0) == 0)
         return;
     try
     {
-        if (procSl == ProcSymlink::direct)
+        if (procSl == ProcSymlink::asLink)
             try
             {
                 if (getItemType(itemPath) == ItemType::symlink) //throw FileError
@@ -554,7 +555,7 @@ void zen::copySymlink(const Zstring& sourcePath, const Zstring& targetPath) //th
     if (::lstat(sourcePath.c_str(), &sourceInfo) != 0)
         THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot read file attributes of %x."), L"%x", fmtPath(sourcePath)), "lstat");
 
-    setWriteTimeNative(targetPath, sourceInfo.st_mtim, ProcSymlink::direct); //throw FileError
+    setWriteTimeNative(targetPath, sourceInfo.st_mtim, ProcSymlink::asLink); //throw FileError
 }
 
 
diff --git a/zen/file_access.h b/zen/file_access.h
index 17c47731..f6a02edc 100644
--- a/zen/file_access.h
+++ b/zen/file_access.h
@@ -29,12 +29,7 @@ using FileIndex = ino_t;
 using FileTimeNative = timespec;
 
 inline time_t nativeFileTimeToTimeT(const timespec& ft) { return ft.tv_sec; } //follow Windows Explorer and always round down!
-inline timespec timetToNativeFileTime(time_t utcTime)
-{
-    timespec natTime = {};
-    natTime.tv_sec = utcTime;
-    return natTime;
-}
+inline timespec timetToNativeFileTime(time_t utcTime) { return {.tv_sec = utcTime}; }
 
 enum class ItemType
 {
@@ -44,15 +39,14 @@ enum class ItemType
 };
 //(hopefully) fast: does not distinguish between error/not existing
 ItemType getItemType(const Zstring& itemPath); //throw FileError
-//execute potentially SLOW folder traversal but distinguish error/not existing
-//  assumes: - base path still exists
-//           - all child item path parts must correspond to folder traversal
+//execute potentially SLOW folder traversal but distinguish error/not existing:
+//  - all child item path parts must correspond to folder traversal
 //  => we can conclude whether an item is *not* existing anymore by doing a *case-sensitive* name search => potentially SLOW!
 std::optional<ItemType> itemStillExists(const Zstring& itemPath); //throw FileError
 
 enum class ProcSymlink
 {
-    direct,
+    asLink,
     follow
 };
 void setFileTime(const Zstring& filePath, time_t modTime, ProcSymlink procSl); //throw FileError
diff --git a/zen/file_path.cpp b/zen/file_path.cpp
index 716dd8de..f5c207f3 100644
--- a/zen/file_path.cpp
+++ b/zen/file_path.cpp
@@ -13,11 +13,12 @@ std::optional<PathComponents> zen::parsePathComponents(const Zstring& itemPath)
 {
     auto doParse = [&](int sepCountVolumeRoot, bool rootWithSep) -> std::optional<PathComponents>
     {
+        assert(sepCountVolumeRoot > 0);
         const Zstring itemPathPf = appendSeparator(itemPath); //simplify analysis of root without separator, e.g. \\server-name\share
-        int sepCount = 0;
+
         for (auto it = itemPathPf.begin(); it != itemPathPf.end(); ++it)
             if (*it == FILE_NAME_SEPARATOR)
-                if (++sepCount == sepCountVolumeRoot)
+                if (--sepCountVolumeRoot == 0)
                 {
                     Zstring rootPath(itemPathPf.begin(), rootWithSep ? it + 1 : it);
 
@@ -89,7 +90,7 @@ bool zen::isValidRelPath(const Zstring& relPath)
     if constexpr (FILE_NAME_SEPARATOR != Zstr('\\')) if (contains(relPath, Zstr('\\'))) return false;
 
     const Zchar doubleSep[] = {FILE_NAME_SEPARATOR, FILE_NAME_SEPARATOR, 0};
-    return !startsWith(relPath, FILE_NAME_SEPARATOR)&& !endsWith(relPath, FILE_NAME_SEPARATOR)&&
+    return !startsWith(relPath, FILE_NAME_SEPARATOR) && !endsWith(relPath, FILE_NAME_SEPARATOR) &&
            !contains(relPath, doubleSep);
 }
 
diff --git a/zen/file_path.h b/zen/file_path.h
index 4a85514b..85af251d 100644
--- a/zen/file_path.h
+++ b/zen/file_path.h
@@ -40,7 +40,7 @@ std::weak_ordering compareNativePath(const Zstring& lhs, const Zstring& rhs);
 
 inline bool equalNativePath(const Zstring& lhs, const Zstring& rhs) { return compareNativePath(lhs, rhs) == std::weak_ordering::equivalent; }
 
-struct LessNativePath { bool operator()(const Zstring& lhs, const Zstring& rhs) const { return std::is_lt(compareNativePath(lhs, rhs)); } };
+struct LessNativePath { bool operator()(const Zstring& lhs, const Zstring& rhs) const { return compareNativePath(lhs, rhs) < 0; } };
 //------------------------------------------------------------------------------------------
 
 
diff --git a/zen/file_traverser.h b/zen/file_traverser.h
index cb7782d6..11c3eaa0 100644
--- a/zen/file_traverser.h
+++ b/zen/file_traverser.h
@@ -17,7 +17,7 @@ struct FileInfo
     Zstring itemName;
     Zstring fullPath;
     uint64_t fileSize = 0; //[bytes]
-    time_t modTime = 0; //number of seconds since Jan. 1st 1970 UTC
+    time_t modTime = 0; //number of seconds since Jan. 1st 1970 GMT
 };
 
 struct FolderInfo
@@ -30,7 +30,7 @@ struct SymlinkInfo
 {
     Zstring itemName;
     Zstring fullPath;
-    time_t modTime = 0; //number of seconds since Jan. 1st 1970 UTC
+    time_t modTime = 0; //number of seconds since Jan. 1st 1970 GMT
 };
 
 //- non-recursive
diff --git a/zen/format_unit.cpp b/zen/format_unit.cpp
index 2aa6e094..8b3fccfe 100644
--- a/zen/format_unit.cpp
+++ b/zen/format_unit.cpp
@@ -168,12 +168,27 @@ std::wstring zen::formatNumber(int64_t n)
 
 std::wstring zen::formatUtcToLocalTime(time_t utcTime)
 {
-    auto errorMsg = [&] { return _("Error") + L" (time_t: " + numberTo<std::wstring>(utcTime) + L')'; };
+    auto fmtFallback = [utcTime] //don't take "no" for an answer!
+    {
+        if (const TimeComp tc = getUtcTime(utcTime);
+            tc != TimeComp())
+        {
+            wchar_t buf[128] = {}; //the only way to format abnormally large or invalid modTime: std::strftime() will fail!
+            if (const int rv = std::swprintf(buf, std::size(buf), L"%d-%02d-%02d  %02d:%02d:%02d GMT", tc.year, tc.month, tc.day, tc.hour, tc.minute, tc.second);
+                0 < rv && rv < std::ssize(buf))
+                return std::wstring(buf, rv);
+        }
+
+        return L"time_t = " + numberTo<std::wstring>(utcTime);
+    };
 
     const TimeComp& loc = getLocalTime(utcTime); //returns TimeComp() on error
 
-    std::wstring dateString = utfTo<std::wstring>(formatTime(Zstr("%x  %X"), loc));
-    return !dateString.empty() ? dateString : errorMsg();
+    /*const*/ std::wstring dateTimeFmt = utfTo<std::wstring>(formatTime(Zstr("%x  %X"), loc));
+    if (dateTimeFmt.empty())
+        return fmtFallback();
+
+    return dateTimeFmt;
 }
 
 
@@ -188,9 +203,9 @@ WeekDay impl::getFirstDayOfWeekImpl() //throw SysError
     const char* firstDay = ::nl_langinfo(_NL_TIME_FIRST_WEEKDAY); //[1-Sunday, 7-Saturday]
     ASSERT_SYSERROR(firstDay && 1 <= *firstDay && *firstDay <= 7);
 
-    const int weekDayStartSunday = *firstDay;
-    const int weekDayStartMonday = (weekDayStartSunday - 1 + 6) % 7; //+6 == -1 in Z_7
-    // [0-Monday, 6-Sunday]
+    const int weekDayStartSunday = *firstDay;                        //[1-Sunday, 7-Saturday]
+    const int weekDayStartMonday = (weekDayStartSunday - 2 + 7) % 7; //[0-Monday, 6-Sunday]  7 == 0 in Z_7
+
     return static_cast<WeekDay>(weekDayStartMonday);
 }
 
diff --git a/zen/process_exec.cpp b/zen/process_exec.cpp
index 6b670508..df41a627 100644
--- a/zen/process_exec.cpp
+++ b/zen/process_exec.cpp
@@ -176,8 +176,7 @@ std::pair<int /*exit code*/, std::string> processExecuteImpl(const Zstring& file
 
             const auto waitTimeMs = std::chrono::duration_cast<std::chrono::milliseconds>(endTime - now).count();
 
-            timeval tv = {};
-            tv.tv_sec  = static_cast<long>(waitTimeMs / 1000);
+            timeval tv{.tv_sec = static_cast<long>(waitTimeMs / 1000)};
             tv.tv_usec = static_cast<long>(waitTimeMs - tv.tv_sec * 1000) * 1000;
 
             fd_set rfd = {}; //includes FD_ZERO
diff --git a/zen/resolve_path.cpp b/zen/resolve_path.cpp
index 357dab6a..99e2f6c6 100644
--- a/zen/resolve_path.cpp
+++ b/zen/resolve_path.cpp
@@ -9,7 +9,7 @@
 #include "thread.h"
 #include "file_access.h"
 
-#include <zen/sys_info.h>
+    #include <zen/sys_info.h>
     //    #include <stdlib.h> //getenv()
     #include <unistd.h> //getuid()
     #include <pwd.h>    //getpwuid_r()
@@ -63,16 +63,16 @@ Zstring resolveRelativePath(const Zstring& relativePath)
             https://www.gnu.org/software/bash/manual/html_node/Tilde-Expansion.html               */
         if (startsWith(pathTmp, "~/") || pathTmp == "~")
         {
-                try
-                {
-                    const Zstring& homePath = getUserHome(); //throw FileError
+            try
+            {
+                const Zstring& homePath = getUserHome(); //throw FileError
 
                 if (startsWith(pathTmp, "~/"))
                     pathTmp = appendPath(homePath, pathTmp.c_str() + 2);
                 else //pathTmp == "~"
                     pathTmp = homePath;
-                }
-                catch (FileError&) {}
+            }
+            catch (FileError&) {}
             //else: error! no further processing!
         }
         else
diff --git a/zen/socket.h b/zen/socket.h
index 5ece29f8..d9517bd8 100644
--- a/zen/socket.h
+++ b/zen/socket.h
@@ -33,11 +33,13 @@ class Socket //throw SysError
 public:
     Socket(const Zstring& server, const Zstring& serviceName) //throw SysError
     {
-        ::addrinfo hints = {};
-        hints.ai_socktype = SOCK_STREAM; //we *do* care about this one!
-        hints.ai_flags = AI_ADDRCONFIG; //save a AAAA lookup on machines that can't use the returned data anyhow
+        const addrinfo hints
+        {
+            .ai_flags = AI_ADDRCONFIG, //save a AAAA lookup on machines that can't use the returned data anyhow
+            .ai_socktype = SOCK_STREAM, //we *do* care about this one!
+        };
 
-        ::addrinfo* servinfo = nullptr;
+        addrinfo* servinfo = nullptr;
         ZEN_ON_SCOPE_EXIT(if (servinfo) ::freeaddrinfo(servinfo));
 
         const int rcGai = ::getaddrinfo(server.c_str(), serviceName.c_str(), &hints, &servinfo);
diff --git a/zen/stl_tools.h b/zen/stl_tools.h
index 2726a09d..66af8551 100644
--- a/zen/stl_tools.h
+++ b/zen/stl_tools.h
@@ -68,10 +68,10 @@ template <class Iterator, class T, class CompLess>
 Iterator binarySearch(Iterator first, Iterator last, const T& value, CompLess less);
 
 //read-only variant of std::merge; input: two sorted ranges
-template <class Iterator, class FunctionLeftOnly, class FunctionBoth, class FunctionRightOnly>
+template <class Iterator, class FunctionLeftOnly, class FunctionBoth, class FunctionRightOnly, class Compare>
 void mergeTraversal(Iterator first1, Iterator last1,
                     Iterator first2, Iterator last2,
-                    FunctionLeftOnly lo, FunctionBoth bo, FunctionRightOnly ro);
+                    FunctionLeftOnly lo, FunctionBoth bo, FunctionRightOnly ro, Compare compare);
 
 //why, oh why is there no std::optional<T>::get()???
 template <class T> inline       T* get(      std::optional<T>& opt) { return opt ? &*opt : nullptr; }
@@ -255,31 +255,32 @@ BidirectionalIterator1 searchLast(const BidirectionalIterator1 first1,       Bid
 //---------------------------------------------------------------------------------------
 
 //read-only variant of std::merge; input: two sorted ranges
-template <class Iterator, class FunctionLeftOnly, class FunctionBoth, class FunctionRightOnly> inline
-void mergeTraversal(Iterator first1, Iterator last1,
-                    Iterator first2, Iterator last2,
-                    FunctionLeftOnly lo, FunctionBoth bo, FunctionRightOnly ro)
+template <class Iterator, class FunctionLeftOnly, class FunctionBoth, class FunctionRightOnly, class Compare> inline
+void mergeTraversal(Iterator firstL, Iterator lastL,
+                    Iterator firstR, Iterator lastR,
+                    FunctionLeftOnly lo, FunctionBoth bo, FunctionRightOnly ro, Compare compare)
 {
-    auto itL = first1;
-    auto itR = first2;
+    auto itL = firstL;
+    auto itR = firstR;
 
-    auto finishLeft  = [&] { std::for_each(itL, last1, lo); };
-    auto finishRight = [&] { std::for_each(itR, last2, ro); };
+    auto finishLeft  = [&] { std::for_each(itL, lastL, lo); };
+    auto finishRight = [&] { std::for_each(itR, lastR, ro); };
 
-    if (itL == last1) return finishRight();
-    if (itR == last2) return finishLeft ();
+    if (itL == lastL) return finishRight();
+    if (itR == lastR) return finishLeft ();
 
     for (;;)
-        if (itL->first < itR->first)
+        if (const std::weak_ordering cmp = compare(*itL, *itR);
+            cmp < 0)
         {
             lo(*itL);
-            if (++itL == last1)
+            if (++itL == lastL)
                 return finishRight();
         }
-        else if (itR->first < itL->first)
+        else if (cmp > 0)
         {
             ro(*itR);
-            if (++itR == last2)
+            if (++itR == lastR)
                 return finishLeft();
         }
         else
@@ -287,8 +288,8 @@ void mergeTraversal(Iterator first1, Iterator last1,
             bo(*itL, *itR);
             ++itL; //
             ++itR; //increment BOTH before checking for end of range!
-            if (itL == last1) return finishRight();
-            if (itR == last2) return finishLeft ();
+            if (itL == lastL) return finishRight();
+            if (itR == lastR) return finishLeft ();
             //simplify loop by placing both EOB checks at the beginning? => slightly slower
         }
 }
diff --git a/zen/string_base.h b/zen/string_base.h
index ace870b9..e18a0f16 100644
--- a/zen/string_base.h
+++ b/zen/string_base.h
@@ -312,9 +312,10 @@ template <class Char, template <class> class SP>        bool operator==(const Zb
 template <class Char, template <class> class SP>        bool operator==(const Zbase<Char, SP>& lhs, const Char*            rhs);
 template <class Char, template <class> class SP> inline bool operator==(const Char*            lhs, const Zbase<Char, SP>& rhs) { return operator==(rhs, lhs); }
 
-template <class Char, template <class> class SP> std::strong_ordering operator<=>(const Zbase<Char, SP>& lhs, const Zbase<Char, SP>& rhs);
-template <class Char, template <class> class SP> std::strong_ordering operator<=>(const Zbase<Char, SP>& lhs, const Char*            rhs);
-template <class Char, template <class> class SP> std::strong_ordering operator<=>(const Char*            lhs, const Zbase<Char, SP>& rhs);
+//follow convention + compare by unsigned char; alternative: std::lexicographical_compare_three_way + reinterpret_cast<const std::make_unsigned_t<Char>*>()
+template <class Char, template <class> class SP> std::strong_ordering operator<=>(const Zbase<Char, SP>& lhs, const Zbase<Char, SP>& rhs) { return compareString(lhs, rhs); }
+template <class Char, template <class> class SP> std::strong_ordering operator<=>(const Zbase<Char, SP>& lhs, const Char*            rhs) { return compareString(lhs, rhs); }
+template <class Char, template <class> class SP> std::strong_ordering operator<=>(const Char*            lhs, const Zbase<Char, SP>& rhs) { return compareString(lhs, rhs); }
 
 template <class Char, template <class> class SP> inline Zbase<Char, SP> operator+(const Zbase<Char, SP>& lhs, const Zbase<Char, SP>& rhs) { return Zbase<Char, SP>(lhs) += rhs; }
 template <class Char, template <class> class SP> inline Zbase<Char, SP> operator+(const Zbase<Char, SP>& lhs, const Char*            rhs) { return Zbase<Char, SP>(lhs) += rhs; }
@@ -495,30 +496,6 @@ bool operator==(const Zbase<Char, SP>& lhs, const Char* rhs)
 
 
 template <class Char, template <class> class SP> inline
-std::strong_ordering operator<=>(const Zbase<Char, SP>& lhs, const Zbase<Char, SP>& rhs)
-{
-    return std::lexicographical_compare_three_way(lhs.begin(), lhs.end(),  //respect embedded 0
-                                                  rhs.begin(), rhs.end()); //
-}
-
-
-template <class Char, template <class> class SP> inline
-std::strong_ordering operator<=>(const Zbase<Char, SP>& lhs, const Char* rhs)
-{
-    return std::lexicographical_compare_three_way(lhs.begin(), lhs.end(), //respect embedded 0
-                                                  rhs, rhs + strLength(rhs));
-}
-
-
-template <class Char, template <class> class SP> inline
-std::strong_ordering operator<=>(const Char* lhs, const Zbase<Char, SP>& rhs)
-{
-    return std::lexicographical_compare_three_way(lhs, lhs + strLength(lhs),
-                                                  rhs.begin(), rhs.end()); //respect embedded 0
-}
-
-
-template <class Char, template <class> class SP> inline
 size_t Zbase<Char, SP>::length() const
 {
     return SP<Char>::length(rawStr_);
diff --git a/zen/string_tools.h b/zen/string_tools.h
index d3f35ce8..cafff3d5 100644
--- a/zen/string_tools.h
+++ b/zen/string_tools.h
@@ -41,7 +41,7 @@ template <class S, class T> bool endsWithAsciiNoCase(const S& str, const T& post
 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> std::strong_ordering compareString(const S& lhs, const T& rhs);
+template <class S, class T> std::strong_ordering compareString(const S& lhs, const T& rhs);
 template <class S, class T> std::weak_ordering compareAsciiNoCase(const S& lhs, const T& rhs); //basic case-insensitive comparison (considering A-Z only!)
 
 //STL container predicates for std::map, std::unordered_set/map
@@ -269,10 +269,12 @@ bool equalAsciiNoCase(const S& lhs, const T& rhs)
 }
 
 
-#if 0
-//support embedded 0, unlike strncmp/wcsncmp:
+namespace impl
+{
+//support embedded 0 (unlike strncmp/wcsncmp) + compare unsigned[!] char
 inline std::strong_ordering strcmpWithNulls(const char*    ptr1, const char*    ptr2, size_t num) { return std:: memcmp(ptr1, ptr2, num) <=> 0; }
 inline std::strong_ordering strcmpWithNulls(const wchar_t* ptr1, const wchar_t* ptr2, size_t num) { return std::wmemcmp(ptr1, ptr2, num) <=> 0; }
+}
 
 template <class S, class T> inline
 std::strong_ordering compareString(const S& lhs, const T& rhs)
@@ -280,13 +282,12 @@ std::strong_ordering compareString(const S& lhs, const T& rhs)
     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(getUpperCase(lhs), getUpperCase(rhs))"
+    //length check *after* strcmpWithNulls(): we DO care about natural ordering
     if (const std::strong_ordering cmp = impl::strcmpWithNulls(strBegin(lhs), strBegin(rhs), std::min(lhsLen, rhsLen));
         cmp != std::strong_ordering::equal)
         return cmp;
     return lhsLen <=> rhsLen;
 }
-#endif
 
 
 template <class S, class T> inline
@@ -587,7 +588,7 @@ struct CopyStringToString
     T copy(const S& src) const
     {
         static_assert(!std::is_same_v<std::decay_t<S>, std::decay_t<T>>);
-        return T(strBegin(src), strLength(src));
+        return {strBegin(src), strLength(src)};
     }
 };
 
@@ -626,11 +627,10 @@ S printNumber(const T& format, const Num& number) //format a single number using
 #endif
     static_assert(std::is_same_v<GetCharTypeT<S>, GetCharTypeT<T>>);
 
-    const int BUFFER_SIZE = 128;
-    GetCharTypeT<S> buffer[BUFFER_SIZE]; //zero-initialize?
-    const int charsWritten = impl::saferPrintf(buffer, BUFFER_SIZE, strBegin(format), number);
+    GetCharTypeT<S> buf[128]; //zero-initialize?
+    const int charsWritten = impl::saferPrintf(buf, std::size(buf), strBegin(format), number);
 
-    return 0 < charsWritten && charsWritten < BUFFER_SIZE ? S(buffer, charsWritten) : S();
+    return 0 < charsWritten && charsWritten < std::ssize(buf) ? S(buf, charsWritten) : S();
 }
 
 
@@ -944,7 +944,7 @@ Num hashString(const S& str)
 
 struct StringHash
 {
-    using is_transparent = int; //allow heterogenous lookup!
+    using is_transparent = int; //enable heterogenous lookup!
 
     template <class String>
     size_t operator()(const String& str) const { return hashString<size_t>(str); }
@@ -953,7 +953,7 @@ struct StringHash
 
 struct StringEqual
 {
-    using is_transparent = int; //allow heterogenous lookup!
+    using is_transparent = int; //enable heterogenous lookup!
 
     template <class String1, class String2>
     bool operator()(const String1& lhs, const String2& rhs) const { return equalString(lhs, rhs); }
@@ -963,7 +963,7 @@ struct StringEqual
 struct LessAsciiNoCase
 {
     template <class String>
-    bool operator()(const String& lhs, const String& rhs) const { return std::is_lt(compareAsciiNoCase(lhs, rhs)); }
+    bool operator()(const String& lhs, const String& rhs) const { return compareAsciiNoCase(lhs, rhs) < 0; }
 };
 
 
diff --git a/zen/string_traits.h b/zen/string_traits.h
index 1a4f4740..31c8c12c 100644
--- a/zen/string_traits.h
+++ b/zen/string_traits.h
@@ -105,8 +105,8 @@ class StringTraits
 public:
     enum
     {
-        isStringClass = hasMemberType_value_type<CleanType> &&
-                        hasMember_c_str         <CleanType> &&
+        isStringClass = hasMemberType_value_type<CleanType>&&
+                        hasMember_c_str         <CleanType>&&
                         hasMember_length        <CleanType>
     };
 
diff --git a/zen/sys_info.cpp b/zen/sys_info.cpp
index bc1bfe62..c57464bc 100644
--- a/zen/sys_info.cpp
+++ b/zen/sys_info.cpp
@@ -111,16 +111,20 @@ ComputerModel zen::getComputerModel() //throw FileError
     {
         auto tryGetInfo = [](const Zstring& filePath)
         {
-            if (!fileAvailable(filePath))
-                return std::wstring();
             try
             {
                 const std::string stream = getFileContent(filePath, nullptr /*notifyUnbufferedIO*/); //throw FileError
                 return utfTo<std::wstring>(trimCpy(stream));
             }
-            catch (const FileError& e) { throw SysError(replaceCpy(e.toString(), L"\n\n", L'\n')); } //errors should be further enriched by context info => SysError
+            catch (FileError&)
+            {
+                if (!itemStillExists(filePath)) //throw FileError
+                    return std::wstring();
+
+                throw;
+            }
         };
-        cm.model  = tryGetInfo("/sys/devices/virtual/dmi/id/product_name"); //throw SysError
+        cm.model  = tryGetInfo("/sys/devices/virtual/dmi/id/product_name"); //throw FileError
         cm.vendor = tryGetInfo("/sys/devices/virtual/dmi/id/sys_vendor");   //
 
         //clean up:
diff --git a/zen/thread.h b/zen/thread.h
index 42fba281..abdc6da0 100644
--- a/zen/thread.h
+++ b/zen/thread.h
@@ -445,7 +445,7 @@ private:
         activeCondition_ = cv;
     }
 
-    std::atomic<bool> stopRequested_{false}; //std:atomic is uninitialized by default!!!
+    std::atomic<bool> stopRequested_{false}; //std::atomic is uninitialized by default!!!
     //"The default constructor is trivial: no initialization takes place other than zero initialization of static and thread-local objects."
 
     std::condition_variable* activeCondition_ = nullptr;
diff --git a/zen/time.h b/zen/time.h
index c2c10fd5..376765be 100644
--- a/zen/time.h
+++ b/zen/time.h
@@ -83,30 +83,32 @@ std::tm toClibTimeComponents(const TimeComp& tc)
            0 <= tc.minute && tc.minute <= 59 &&
            0 <= tc.second && tc.second <= 61);
 
-    std::tm ctc = {};
-    ctc.tm_year  = tc.year - 1900; //years since 1900
-    ctc.tm_mon   = tc.month - 1;   //0-11
-    ctc.tm_mday  = tc.day;         //1-31
-    ctc.tm_hour  = tc.hour;        //0-23
-    ctc.tm_min   = tc.minute;      //0-59
-    ctc.tm_sec   = tc.second;      //0-60 (including leap second)
-    ctc.tm_isdst = -1;             //> 0 if DST is active, == 0 if DST is not active, < 0 if the information is not available
-    //ctc.tm_wday
-    //ctc.tm_yday
-    return ctc;
+    return
+    {
+        .tm_sec   = tc.second,      //0-60 (including leap second)
+        .tm_min   = tc.minute,      //0-59
+        .tm_hour  = tc.hour,        //0-23
+        .tm_mday  = tc.day,         //1-31
+        .tm_mon   = tc.month - 1,   //0-11
+        .tm_year  = tc.year - 1900, //years since 1900
+        .tm_isdst = -1,             //> 0 if DST is active, == 0 if DST is not active, < 0 if the information is not available
+        //.tm_wday
+        //.tm_yday
+    };
 }
 
 inline
 TimeComp toZenTimeComponents(const std::tm& ctc)
 {
-    TimeComp tc;
-    tc.year   = ctc.tm_year + 1900;
-    tc.month  = ctc.tm_mon + 1;
-    tc.day    = ctc.tm_mday;
-    tc.hour   = ctc.tm_hour;
-    tc.minute = ctc.tm_min;
-    tc.second = ctc.tm_sec;
-    return tc;
+    return
+    {
+        .year   = ctc.tm_year + 1900,
+        .month  = ctc.tm_mon + 1,
+        .day    = ctc.tm_mday,
+        .hour   = ctc.tm_hour,
+        .minute = ctc.tm_min,
+        .second = ctc.tm_sec,
+    };
 }
 
 
@@ -235,12 +237,12 @@ std::pair<time_t, bool /*success*/> localToTimeT(const TimeComp& tc) //convert l
 
     const int cycles400 = numeric::intDivFloor(ctc.tm_year + 1900 - 1971/*[!]*/, 400); //see utcToTimeT()
     //1971: ensures resulting time_t >= 0 after time zone, DST adaption, or std::mktime will fail on Windows!
-    ctc.tm_year -= 400 * cycles400;                                       
+    ctc.tm_year -= 400 * cycles400;
 
     const time_t locTime = std::mktime(&ctc);
     if (locTime == -1)
         return {};
-    
+
     assert(locTime > 0);
     return {locTime + secsPer400Years * cycles400, true};
 }
diff --git a/zen/utf.h b/zen/utf.h
index 9c9cf7d1..ca231602 100644
--- a/zen/utf.h
+++ b/zen/utf.h
@@ -7,8 +7,6 @@
 #ifndef UTF_H_01832479146991573473545
 #define UTF_H_01832479146991573473545
 
-//#include <cstdint>
-//#include <iterator>
 #include "string_tools.h" //copyStringTo
 
 
@@ -45,8 +43,8 @@ using CodePoint = uint32_t;
 using Char16    = uint16_t;
 using Char8     = uint8_t;
 
-const CodePoint LEAD_SURROGATE      = 0xd800;
-const CodePoint TRAIL_SURROGATE     = 0xdc00; //== LEAD_SURROGATE_MAX + 1
+const CodePoint LEAD_SURROGATE      = 0xd800; //1101 1000 0000 0000    LEAD_SURROGATE_MAX = TRAIL_SURROGATE - 1
+const CodePoint TRAIL_SURROGATE     = 0xdc00; //1101 1100 0000 0000
 const CodePoint TRAIL_SURROGATE_MAX = 0xdfff;
 
 const CodePoint REPLACEMENT_CHAR    = 0xfffd;
@@ -62,31 +60,17 @@ void codePointToUtf16(CodePoint cp, Function writeOutput) //"writeOutput" is a u
     if (cp < LEAD_SURROGATE)
         writeOutput(static_cast<Char16>(cp));
     else if (cp <= TRAIL_SURROGATE_MAX) //invalid code point
-        codePointToUtf16(REPLACEMENT_CHAR, writeOutput); //resolves to 1-character utf16
-    else if (cp < 0x10000)
+        writeOutput(static_cast<Char16>(REPLACEMENT_CHAR));
+    else if (cp <= 0xffff)
         writeOutput(static_cast<Char16>(cp));
     else if (cp <= CODE_POINT_MAX)
     {
         cp -= 0x10000;
         writeOutput(static_cast<Char16>( LEAD_SURROGATE + (cp >> 10)));
-        writeOutput(static_cast<Char16>(TRAIL_SURROGATE + (cp & 0x3ff)));
+        writeOutput(static_cast<Char16>(TRAIL_SURROGATE + (cp & 0b11'1111'1111)));
     }
     else //invalid code point
-        codePointToUtf16(REPLACEMENT_CHAR, writeOutput); //resolves to 1-character utf16
-}
-
-
-inline
-size_t getUtf16Len(Char16 ch) //ch must be first code unit! returns 0 on error!
-{
-    if (ch < LEAD_SURROGATE)
-        return 1;
-    else if (ch < TRAIL_SURROGATE)
-        return 2;
-    else if (ch <= TRAIL_SURROGATE_MAX)
-        return 0; //unexpected trail surrogate!
-    else
-        return 1;
+        writeOutput(static_cast<Char16>(REPLACEMENT_CHAR));
 }
 
 
@@ -102,17 +86,14 @@ public:
 
         const Char16 ch = *it_++;
         CodePoint cp = ch;
-        switch (getUtf16Len(ch))
-        {
-            case 0: //invalid utf16 character
-                cp = REPLACEMENT_CHAR;
-                break;
-            case 1:
-                break;
-            case 2:
-                decodeTrail(cp);
-                break;
-        }
+
+        if (ch < LEAD_SURROGATE || ch > TRAIL_SURROGATE_MAX) //single Char16, no surrogates
+            ;
+        else if (ch < TRAIL_SURROGATE) //two Char16: lead and trail surrogates
+            decodeTrail(cp); //no range check needed: cp is inside [U+010000, U+10FFFF] by construction
+        else //unexpected trail surrogate
+            cp = REPLACEMENT_CHAR;
+
         return cp;
     }
 
@@ -141,46 +122,37 @@ private:
 template <class Function> inline
 void codePointToUtf8(CodePoint cp, Function writeOutput) //"writeOutput" is a unary function taking a Char8
 {
-    //https://en.wikipedia.org/wiki/UTF-8
-    //assert(cp < LEAD_SURROGATE || TRAIL_SURROGATE_MAX < cp); //code points [0xd800, 0xdfff] are reserved for UTF-16 and *should* not be encoded in UTF-8
+    /* https://en.wikipedia.org/wiki/UTF-8
+      "high and low surrogate halves used by UTF-16 (U+D800 through U+DFFF) and
+       code points not encodable by UTF-16 (those after U+10FFFF) [...] must be treated as an invalid byte sequence" */
 
-    if (cp < 0x80)
+    if (cp <= 0b111'1111)
         writeOutput(static_cast<Char8>(cp));
-    else if (cp < 0x800)
+    else if (cp <= 0b0111'1111'1111)
     {
-        writeOutput(static_cast<Char8>((cp >> 6  ) | 0xc0));
-        writeOutput(static_cast<Char8>((cp & 0x3f) | 0x80));
+        writeOutput(static_cast<Char8>((cp >> 6)        | 0b1100'0000)); //110x xxxx
+        writeOutput(static_cast<Char8>((cp & 0b11'1111) | 0b1000'0000)); //10xx xxxx
     }
-    else if (cp < 0x10000)
+    else if (cp <= 0b1111'1111'1111'1111)
     {
-        writeOutput(static_cast<Char8>( (cp >> 12       ) | 0xe0));
-        writeOutput(static_cast<Char8>(((cp >> 6) & 0x3f) | 0x80));
-        writeOutput(static_cast<Char8>( (cp       & 0x3f) | 0x80));
+        if (LEAD_SURROGATE <= cp && cp <= TRAIL_SURROGATE_MAX) //[0xd800, 0xdfff]
+            codePointToUtf8(REPLACEMENT_CHAR, writeOutput);
+        else
+        {
+            writeOutput(static_cast<Char8>( (cp >> 12)             | 0b1110'0000)); //1110 xxxx
+            writeOutput(static_cast<Char8>(((cp >> 6) & 0b11'1111) | 0b1000'0000)); //10xx xxxx
+            writeOutput(static_cast<Char8>( (cp       & 0b11'1111) | 0b1000'0000)); //10xx xxxx
+        }
     }
     else if (cp <= CODE_POINT_MAX)
     {
-        writeOutput(static_cast<Char8>( (cp >> 18        ) | 0xf0));
-        writeOutput(static_cast<Char8>(((cp >> 12) & 0x3f) | 0x80));
-        writeOutput(static_cast<Char8>(((cp >> 6)  & 0x3f) | 0x80));
-        writeOutput(static_cast<Char8>( (cp        & 0x3f) | 0x80));
+        writeOutput(static_cast<Char8>( (cp >> 18)              | 0b1111'0000)); //1111 0xxx
+        writeOutput(static_cast<Char8>(((cp >> 12) & 0b11'1111) | 0b1000'0000)); //10xx xxxx
+        writeOutput(static_cast<Char8>(((cp >> 6)  & 0b11'1111) | 0b1000'0000)); //10xx xxxx
+        writeOutput(static_cast<Char8>( (cp        & 0b11'1111) | 0b1000'0000)); //10xx xxxx
     }
     else //invalid code point
-        codePointToUtf8(REPLACEMENT_CHAR, writeOutput); //resolves to 3-byte utf8
-}
-
-
-inline
-size_t getUtf8Len(Char8 ch) //ch must be first code unit! returns 0 on error!
-{
-    if (ch < 0x80)
-        return 1;
-    if (ch >> 5 == 0x6)
-        return 2;
-    if (ch >> 4 == 0xe)
-        return 3;
-    if (ch >> 3 == 0x1e)
-        return 4;
-    return 0; //invalid begin of UTF8 encoding
+        codePointToUtf8(REPLACEMENT_CHAR, writeOutput); //resolves to 3-byte UTF8
 }
 
 
@@ -196,30 +168,34 @@ public:
 
         const Char8 ch = *it_++;
         CodePoint cp = ch;
-        switch (getUtf8Len(ch))
+
+        if (ch < 0x80) //1 byte
+            ;
+        else if (ch >> 5 == 0b110) //2 bytes
         {
-            case 0: //invalid utf8 character
-                cp = REPLACEMENT_CHAR;
-                break;
-            case 1:
-                break;
-            case 2:
-                cp &= 0x1f;
-                decodeTrail(cp);
-                break;
-            case 3:
-                cp &= 0xf;
-                if (decodeTrail(cp))
-                    decodeTrail(cp);
-                break;
-            case 4:
-                cp &= 0x7;
-                if (decodeTrail(cp))
-                    if (decodeTrail(cp))
-                        decodeTrail(cp);
-                if (cp > CODE_POINT_MAX) cp = REPLACEMENT_CHAR;
-                break;
+            cp &= 0b1'1111;
+            if (decodeTrail(cp))
+                if (cp <= 0b111'1111) //overlong encoding: "correct encoding of a code point uses only the minimum number of bytes required"
+                    cp = REPLACEMENT_CHAR;
         }
+        else if (ch >> 4 == 0b1110) //3 bytes
+        {
+            cp &= 0b1111;
+            if (decodeTrail(cp) && decodeTrail(cp))
+                if (cp <= 0b0111'1111'1111 ||
+                    (LEAD_SURROGATE <= cp && cp <= TRAIL_SURROGATE_MAX)) //[0xd800, 0xdfff] are invalid code points
+                    cp = REPLACEMENT_CHAR;
+        }
+        else if (ch >> 3 == 0b11110) //4 bytes
+        {
+            cp &= 0b111;
+            if (decodeTrail(cp) && decodeTrail(cp) && decodeTrail(cp))
+                if (cp <= 0b1111'1111'1111'1111 || cp > CODE_POINT_MAX)
+                    cp = REPLACEMENT_CHAR;
+        }
+        else //invalid begin of UTF8 encoding
+            cp = REPLACEMENT_CHAR;
+
         return cp;
     }
 
@@ -229,9 +205,9 @@ private:
         if (it_ != last_) //trail surrogate expected!
         {
             const Char8 ch = *it_;
-            if (ch >> 6 == 0x2) //trail surrogate expected!
+            if (ch >> 6 == 0b10) //trail surrogate expected!
             {
-                cp = (cp << 6) + (ch & 0x3f);
+                cp = (cp << 6) + (ch & 0b11'1111);
                 ++it_;
                 return true;
             }
@@ -337,7 +313,9 @@ UtfString getUnicodeSubstring(const UtfString& str, size_t uniPosFirst, size_t u
     assert(uniPosFirst <= uniPosLast && uniPosLast <= unicodeLength(str));
     using namespace impl;
     using CharType = GetCharTypeT<UtfString>;
+
     UtfString output;
+    assert(uniPosFirst <= uniPosLast);
     if (uniPosFirst >= uniPosLast) //optimize for empty range
         return output;
 
@@ -357,6 +335,10 @@ UtfString getUnicodeSubstring(const UtfString& str, size_t uniPosFirst, size_t u
 namespace impl
 {
 template <class TargetString, class SourceString> inline
+TargetString utfTo(const SourceString& str, std::true_type) { return copyStringTo<TargetString>(str); }
+
+
+template <class TargetString, class SourceString> inline
 TargetString utfTo(const SourceString& str, std::false_type)
 {
     using CharSrc = GetCharTypeT<SourceString>;
@@ -371,10 +353,6 @@ TargetString utfTo(const SourceString& str, std::false_type)
 
     return output;
 }
-
-
-template <class TargetString, class SourceString> inline
-TargetString utfTo(const SourceString& str, std::true_type) { return copyStringTo<TargetString>(str); }
 }
 
 
diff --git a/zen/zstring.cpp b/zen/zstring.cpp
index 76c0a81f..1e29e461 100644
--- a/zen/zstring.cpp
+++ b/zen/zstring.cpp
@@ -11,46 +11,44 @@
 using namespace zen;
 
 
-Zstring getUnicodeNormalForm(const Zstring& str)
+Zstring getUnicodeNormalFormNonAscii(const Zstring& str)
 {
-    //fast pre-check:
-    if (isAsciiString(str)) //perf: in the range of 3.5ns
-        return str;
-    static_assert(std::is_same_v<decltype(str), const Zbase<Zchar>&>, "god bless our ref-counting! => save output string memory consumption!");
-
     //Example: const char* decomposed  = "\x6f\xcc\x81";
     //         const char* precomposed = "\xc3\xb3";
+    assert(!isAsciiString(str));
+    assert(str.find(Zchar('\0')) == Zstring::npos); //don't expect embedded nulls!
+
     try
     {
         gchar* outStr = ::g_utf8_normalize(str.c_str(), str.length(), G_NORMALIZE_DEFAULT_COMPOSE);
         if (!outStr)
-            throw SysError(formatSystemError("g_utf8_normalize(" + utfTo<std::string>(str) + ')', L"", L"Conversion failed."));
+            throw SysError(formatSystemError("g_utf8_normalize", L"", L"Conversion failed."));
         ZEN_ON_SCOPE_EXIT(::g_free(outStr));
         return outStr;
 
     }
-    catch ([[maybe_unused]] const SysError& e)
+    catch (const SysError& e)
     {
-        assert(false);
-        return str;
+        throw std::runtime_error(std::string(__FILE__) + '[' + numberTo<std::string>(__LINE__) + "] Error normalizing string:" +
+                                 '\n' + utfTo<std::string>(str)  + "\n\n" + utfTo<std::string>(e.toString()));
     }
 }
 
 
-Zstring getUpperCase(const Zstring& str)
+Zstring getUnicodeNormalForm(const Zstring& str)
 {
-    assert(str.find(Zchar('\0')) == Zstring::npos); //don't expect embedded nulls!
-
     //fast pre-check:
     if (isAsciiString(str)) //perf: in the range of 3.5ns
-    {
-        Zstring output = str;
-        for (Zchar& c : output)
-            c = asciiToUpper(c);
-        return output;
-    }
+        return str;
+    static_assert(std::is_same_v<decltype(str), const Zbase<Zchar>&>, "god bless our ref-counting! => save output string memory consumption!");
 
-    Zstring strNorm = getUnicodeNormalForm(str);
+    return getUnicodeNormalFormNonAscii(str);
+}
+
+
+Zstring getUpperCaseNonAscii(const Zstring& str)
+{
+    Zstring strNorm = getUnicodeNormalFormNonAscii(str);
     try
     {
         static_assert(sizeof(impl::CodePoint) == sizeof(gunichar));
@@ -64,11 +62,26 @@ Zstring getUpperCase(const Zstring& str)
         return output;
 
     }
-    catch (SysError&)
+    catch (const SysError& e)
     {
-        assert(false);
-        return str;
+        throw std::runtime_error(std::string(__FILE__) + '[' + numberTo<std::string>(__LINE__) + "] Error converting string to upper case:" +
+                                 '\n' + utfTo<std::string>(str)  + "\n\n" + utfTo<std::string>(e.toString()));
+    }
+}
+
+
+Zstring getUpperCase(const Zstring& str)
+{
+    if (isAsciiString(str)) //fast path: in the range of 3.5ns
+    {
+        Zstring output = str;
+        for (Zchar& c : output)  //identical to LCMapStringEx(), g_unichar_toupper(), CFStringUppercase() [verified!]
+            c = asciiToUpper(c); //
+        return output;
     }
+    //else: slow path --------------------------------------
+
+    return getUpperCaseNonAscii(str);
 }
 
 
@@ -91,10 +104,10 @@ std::weak_ordering compareNoCaseUtf8(const char* lhs, size_t lhsLen, const char*
 
         static_assert(sizeof(gunichar) == sizeof(impl::CodePoint));
 
+        //ordering: "to lower" converts to higher code points than "to upper"
         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 makeUnsigned(charL) <=> makeUnsigned(charR); //unsigned char-comparison is the convention!
     }
 }
@@ -107,78 +120,111 @@ std::weak_ordering compareNatural(const Zstring& lhs, const Zstring& rhs)
           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!
-        - don't follow broken "strnatcasecmp": https://github.com/php/php-src/blob/master/ext/standard/strnatcmp.c
-                1. incorrect non-ASCII CI-comparison
-                2. incorrect bounds checks
-                3. incorrect trimming of *all* whitespace
-                4. arbitrary handling of leading 0 only at string begin
-                5. incorrect handling of whitespace following a number
-                6. code is a mess                                          */
-    for (;;)
+    try
     {
-        if (strL == strEndL || strR == strEndR)
-            return (strL != strEndL) <=> (strR != strEndR); //"nothing" before "something"
-        //note: "something" never would have been condensed to "nothing" further below => can finish evaluation here
-
-        const bool wsL = isWhiteSpace(*strL);
-        const bool wsR = isWhiteSpace(*strR);
-        if (wsL != wsR)
-            return !wsL <=> !wsR; //whitespace before non-ws!
-        if (wsL)
-        {
-            ++strL, ++strR;
-            while (strL != strEndL && isWhiteSpace(*strL)) ++strL;
-            while (strR != strEndR && isWhiteSpace(*strR)) ++strR;
-            continue;
-        }
-
-        const bool digitL = isDigit(*strL);
-        const bool digitR = isDigit(*strR);
-        if (digitL != digitR)
-            return !digitL <=> !digitR; //numbers before chars!
-        if (digitL)
+        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!
+            - don't follow broken "strnatcasecmp": https://github.com/php/php-src/blob/master/ext/standard/strnatcmp.c
+                    1. incorrect non-ASCII CI-comparison
+                    2. incorrect bounds checks
+                    3. incorrect trimming of *all* whitespace
+                    4. arbitrary handling of leading 0 only at string begin
+                    5. incorrect handling of whitespace following a number
+                    6. code is a mess                                          */
+        for (;;)
         {
-            while (strL != strEndL && *strL == '0') ++strL;
-            while (strR != strEndR && *strR == '0') ++strR;
+            if (strL == strEndL || strR == strEndR)
+                return (strL != strEndL) <=> (strR != strEndR); //"nothing" before "something"
+            //note: "something" never would have been condensed to "nothing" further below => can finish evaluation here
+
+            const bool wsL = isWhiteSpace(*strL);
+            const bool wsR = isWhiteSpace(*strR);
+            if (wsL != wsR)
+                return !wsL <=> !wsR; //whitespace before non-ws!
+            if (wsL)
+            {
+                ++strL, ++strR;
+                while (strL != strEndL && isWhiteSpace(*strL)) ++strL;
+                while (strR != strEndR && isWhiteSpace(*strR)) ++strR;
+                continue;
+            }
 
-            int rv = 0;
-            for (;; ++strL, ++strR)
+            const bool digitL = isDigit(*strL);
+            const bool digitR = isDigit(*strR);
+            if (digitL != digitR)
+                return !digitL <=> !digitR; //numbers before chars!
+            if (digitL)
             {
-                const bool endL = strL == strEndL || !isDigit(*strL);
-                const bool endR = strR == strEndR || !isDigit(*strR);
-                if (endL != endR)
-                    return !endL <=> !endR; //more digits means bigger number
-                if (endL)
-                    break; //same number of digits
-
-                if (rv == 0 && *strL != *strR)
-                    rv = *strL - *strR; //found first digit difference comparing from left
+                while (strL != strEndL && *strL == '0') ++strL;
+                while (strR != strEndR && *strR == '0') ++strR;
+
+                int rv = 0;
+                for (;; ++strL, ++strR)
+                {
+                    const bool endL = strL == strEndL || !isDigit(*strL);
+                    const bool endR = strR == strEndR || !isDigit(*strR);
+                    if (endL != endR)
+                        return !endL <=> !endR; //more digits means bigger number
+                    if (endL)
+                        break; //same number of digits
+
+                    if (rv == 0 && *strL != *strR)
+                        rv = *strL - *strR; //found first digit difference comparing from left
+                }
+                if (rv != 0)
+                    return rv <=> 0;
+                continue;
             }
-            if (rv != 0)
-                return rv <=> 0;
-            continue;
+
+            //compare full junks of text: consider unicode encoding!
+            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;
+
+            if (const std::weak_ordering cmp = compareNoCaseUtf8(textBeginL, strL - textBeginL, textBeginR, strR - textBeginR);
+                cmp != std::weak_ordering::equivalent)
+                return cmp;
         }
 
-        //compare full junks of text: consider unicode encoding!
-        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;
+    }
+    catch (const SysError& e)
+    {
+        throw std::runtime_error(std::string(__FILE__) + '[' + numberTo<std::string>(__LINE__) + "] Error comparing strings:" + '\n' +
+                                 utfTo<std::string>(lhs) + '\n' + utfTo<std::string>(rhs) + "\n\n" + utfTo<std::string>(e.toString()));
+    }
+}
+
 
-        if (const std::weak_ordering cmp = compareNoCaseUtf8(textBeginL, strL - textBeginL, textBeginR, strR - textBeginR);
-            cmp != std::weak_ordering::equivalent)
-            return cmp;
+std::weak_ordering compareNoCase(const Zstring& lhs, const Zstring& rhs)
+{
+    //fast path: no need for extra memory allocations => ~ 6x speedup
+    const size_t minSize = std::min(lhs.size(), rhs.size());
+
+    size_t i = 0;
+    for (; i < minSize; ++i)
+    {
+        const Zchar l = lhs[i];
+        const Zchar r = rhs[i];
+        if (!isAsciiChar(l) || !isAsciiChar(r))
+            goto slowPath; //=> let's NOT make assumptions how getUpperCase() compares "ASCII <=> non-ASCII"
+
+        const Zchar lUp = asciiToUpper(l); //
+        const Zchar rUp = asciiToUpper(r); //no surprises: emulate getUpperCase() [verified!]
+        if (lUp != rUp)                    //
+            return lUp <=> rUp;            //
     }
+    return lhs.size() <=> rhs.size();
+slowPath: //--------------------------------------
 
+    return compareNoCaseUtf8(lhs.c_str() + i, lhs.size() - i, 
+                             rhs.c_str() + i, rhs.size() - i);
 }
diff --git a/zen/zstring.h b/zen/zstring.h
index bc7cfb06..70b9f448 100644
--- a/zen/zstring.h
+++ b/zen/zstring.h
@@ -39,7 +39,7 @@ Zstring getUnicodeNormalForm(const Zstring& str);
 Zstring getUpperCase(const Zstring& str);
 
 //------------------------------------------------------------------------------------------
-struct ZstringNorm //use as STL container key: avoid needless Unicode normalizations during std::map<>::find()
+struct ZstringNorm //use as STL container key: better than repeated Unicode normalizations during std::map<>::find()
 {
     /*explicit*/ ZstringNorm(const Zstring& str) : normStr(getUnicodeNormalForm(str)) {}
     Zstring normStr;
@@ -51,7 +51,7 @@ template<> struct std::hash<ZstringNorm> { size_t operator()(const ZstringNorm&
 //struct LessUnicodeNormal { bool operator()(const Zstring& lhs, const Zstring& rhs) const { return getUnicodeNormalForm(lhs) < getUnicodeNormalForm(rhs); } };
 
 //------------------------------------------------------------------------------------------
-struct ZstringNoCase //use as STL container key: avoid needless upper-case conversions during std::map<>::find()
+struct ZstringNoCase //use as STL container key: better than repeated upper-case conversions during std::map<>::find()
 {
     /*explicit*/ ZstringNoCase(const Zstring& str) : upperCase(getUpperCase(str)) {}
     Zstring upperCase;
@@ -60,12 +60,18 @@ struct ZstringNoCase //use as STL container key: avoid needless upper-case conve
 };
 template<> struct std::hash<ZstringNoCase> { size_t operator()(const ZstringNoCase& str) const { return std::hash<Zstring>()(str.upperCase); } };
 
-inline bool equalNoCase(const Zstring& lhs, const Zstring& rhs) { return getUpperCase(lhs) == getUpperCase(rhs); }
+
+std::weak_ordering compareNoCase(const Zstring& lhs, const Zstring& rhs);
+
+inline
+bool equalNoCase(const Zstring& lhs, const Zstring& rhs) { return compareNoCase(lhs, rhs) == std::weak_ordering::equivalent;  }
+//note: the "lhs.size() != rhs.size()" short-cut would require two isAsciiString() checks
+//=> generally SLOWER than starting comparison directly during first pass and breaking on first difference!
 
 //------------------------------------------------------------------------------------------
 std::weak_ordering compareNatural(const Zstring& lhs, const Zstring& rhs);
 
-struct LessNaturalSort { bool operator()(const Zstring& lhs, const Zstring& rhs) const { return std::is_lt(compareNatural(lhs, rhs)); } };
+struct LessNaturalSort { bool operator()(const Zstring& lhs, const Zstring& rhs) const { return compareNatural(lhs, rhs) < 0; } };
 
 
 //------------------------------------------------------------------------------------------
@@ -73,16 +79,18 @@ struct LessNaturalSort { bool operator()(const Zstring& lhs, const Zstring& rhs)
 const wchar_t EN_DASH = L'\u2013';
 const wchar_t EM_DASH = L'\u2014';
     const wchar_t* const SPACED_DASH = L" \u2014 "; //using 'EM DASH'
-const wchar_t LTR_MARK = L'\u200E'; //UTF-8: E2 80 8E
 const wchar_t* const ELLIPSIS = L"\u2026"; //"..."
 const wchar_t MULT_SIGN = L'\u00D7'; //fancy "x"
 //const wchar_t NOBREAK_SPACE = L'\u00A0';
 const wchar_t ZERO_WIDTH_SPACE = L'\u200B';
 
+const wchar_t LTR_MARK = L'\u200E'; //UTF-8: E2 80 8E
 const wchar_t RTL_MARK = L'\u200F'; //UTF-8: E2 80 8F https://www.w3.org/International/questions/qa-bidi-unicode-controls
-const wchar_t BIDI_DIR_ISOLATE_RTL    = L'\u2067'; //UTF-8: E2 81 A7 => not working on Win 10
-const wchar_t BIDI_POP_DIR_ISOLATE    = L'\u2069'; //UTF-8: E2 81 A9 => not working on Win 10
-const wchar_t BIDI_DIR_EMBEDDING_RTL  = L'\u202B'; //UTF-8: E2 80 AB => not working on Win 10
-const wchar_t BIDI_POP_DIR_FORMATTING = L'\u202C'; //UTF-8: E2 80 AC => not working on Win 10
+//const wchar_t BIDI_DIR_ISOLATE_RTL    = L'\u2067'; //=> not working on Win 10
+//const wchar_t BIDI_POP_DIR_ISOLATE    = L'\u2069'; //=> not working on Win 10
+//const wchar_t BIDI_DIR_EMBEDDING_RTL  = L'\u202B'; //=> not working on Win 10
+//const wchar_t BIDI_POP_DIR_FORMATTING = L'\u202C'; //=> not working on Win 10
+
+const wchar_t* const TAB_SPACE = L"    "; //4: the only sensible space count for tabs
 
 #endif //ZSTRING_H_73425873425789