1 files changed, 23 insertions, 10 deletions

diff --git a/lib/shadow.cpp b/lib/shadow.cpp
index d3106168..4bb299ac 100644
--- a/lib/shadow.cpp
+++ b/lib/shadow.cpp
@@ -8,7 +8,10 @@
 #include <stdexcept>
 #include <zen/win.h> //includes "windows.h"
 #include <zen/dll.h>
+#include <zen/win_ver.h>
 #include <zen/assert_static.h>
+#include <zen/long_path_prefix.h>
+#include <zen/symlink_target.h>
 #include "ShadowCopy/shadow.h"
 #include <zen/scope_guard.h>
 
@@ -31,6 +34,8 @@ bool runningWOW64() //test if process is running under WOW64 (reference http://m
     }
     return false;
 }
+
+const bool wereVistaOrLater = vistaOrLater(); //thread-safety: init at startup
 }
 
 //#############################################################################################################
@@ -51,14 +56,13 @@ public:
             throw FileError(_("Cannot access Volume Shadow Copy Service.") + L"\n" +
                             _("Please use FreeFileSync 64-bit version to create shadow copies on this system."));
 
-
         //check if shadow copy dll was loaded correctly
         if (!createShadowCopy || !releaseShadowCopy || !getShadowVolume || !getLastError)
             throw FileError(_("Cannot access Volume Shadow Copy Service.") + L"\n" +
                             replaceCpy(_("Cannot load file %x."), L"%x", fmtFileName(getDllName())));
 
         //---------------------------------------------------------------------------------------------------------
-        //start shadow volume copy service:
+        //start volume shadow copy service:
         backupHandle = createShadowCopy(volumeNamePf.c_str());
         if (!backupHandle)
             throw FileError(_("Cannot access Volume Shadow Copy Service.") + L"\n" +
@@ -88,22 +92,31 @@ private:
 
 Zstring ShadowCopy::makeShadowCopy(const Zstring& inputFile, const std::function<void(const Zstring&)>& onBeforeMakeVolumeCopy)
 {
+    Zstring filenameFinal = inputFile;
+
+    //try to resolve symlinks and junctions:
+    //1. symlinks: we need to retrieve the target path, else we would just return a symlink on a VSS volume while the target outside were still locked!
+    //2. junctions: C:\Users\<username> is a junction that may link to e.g. D:\Users\<username>, so GetVolumePathName() returns "D:\" => "Volume name %x not part of file name %y!"
+    if (wereVistaOrLater)
+        filenameFinal = getResolvedFilePath(inputFile); //throw FileError; requires Vista or later!
+    //-> returns paths with \\?\ prefix! => make sure to avoid duplicate shadow copies for volume paths with/without prefix
+
     DWORD bufferSize = 10000;
     std::vector<wchar_t> volBuffer(bufferSize);
-    if (!::GetVolumePathName(inputFile.c_str(), //__in   LPCTSTR lpszFileName,
-                             &volBuffer[0],     //__out  LPTSTR lpszVolumePathName,
-                             bufferSize))       //__in   DWORD cchBufferLength
-        throw FileError(replaceCpy(_("Path %x does not contain a volume name."), L"%x", fmtFileName(inputFile)));
+    if (!::GetVolumePathName(filenameFinal.c_str(), //__in   LPCTSTR lpszFileName,
+                             &volBuffer[0],         //__out  LPTSTR lpszVolumePathName,
+                             bufferSize))           //__in   DWORD cchBufferLength
+        throw FileError(replaceCpy(_("Path %x does not contain a volume name."), L"%x", fmtFileName(filenameFinal)));
 
-    const Zstring volumeNamePf = appendSeparator(&volBuffer[0]);
+    const Zstring volumeNamePf = appendSeparator(&volBuffer[0]); //msdn: if buffer is 1 char too short, GetVolumePathName() may skip last separator without error!
 
     //input file is always absolute! directory formatting takes care of this! Therefore volume name can always be found.
-    const size_t pos = inputFile.find(volumeNamePf); //inputFile needs NOT to begin with volumeNamePf: consider for example \\?\ prefix!
+    const size_t pos = filenameFinal.find(volumeNamePf); //filenameFinal needs NOT to begin with volumeNamePf: consider for example \\?\ prefix!
     if (pos == Zstring::npos)
     {
         std::wstring msg = _("Volume name %x not part of file name %y!");
         replace(msg, L"%x", fmtFileName(volumeNamePf), false);
-        replace(msg, L"%y", fmtFileName(inputFile), false);
+        replace(msg, L"%y", fmtFileName(filenameFinal), false);
         throw FileError(msg);
     }
 
@@ -117,5 +130,5 @@ Zstring ShadowCopy::makeShadowCopy(const Zstring& inputFile, const std::function
     }
 
     //return filename alias on shadow copy volume
-    return it->second->geNamePf() + Zstring(inputFile.c_str() + pos + volumeNamePf.length());
+    return it->second->geNamePf() + Zstring(filenameFinal.c_str() + pos + volumeNamePf.length());
 }