Fix KDiff3 & Nexus Mod Manager Compaitibility Issues Regarding Symbolic Links

WitcherScriptMerger/Extensions.cs

@@ -8,6 +8,8 @@
 
 namespace WitcherScriptMerger
 {
+    using System.IO;
+
     static class Extensions
     {
         #region Strings
@@ -56,6 +58,13 @@ public static string GetPluralS(this int num)
 
         #endregion
 
+        #region FileInfo
+        public static string ResolveTargetFileFullName(this FileInfo fileInfo)
+        {
+            return fileInfo.Exists ? SimLink.GetSymbolicLinkTarget(fileInfo) : fileInfo.FullName;
+        }
+        #endregion
+
         #region Tree & Context Menu
 
         public static IEnumerable<ToolStripItem> GetAvailableItems(this ContextMenuStrip menu)

WitcherScriptMerger/SimLink.cs

@@ -0,0 +1,61 @@
+using System;
+using System.ComponentModel;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Text;
+using Microsoft.Win32.SafeHandles;
+
+namespace WitcherScriptMerger
+{
+    /// <summary>
+    ///     Provides access to NTFS junction points in .Net.
+    /// </summary>
+    public static class SimLink
+    {
+        private const int CREATION_DISPOSITION_OPEN_EXISTING = 3;
+
+        private const int FILE_FLAG_BACKUP_SEMANTICS = 0x02000000;
+
+        // http://msdn.microsoft.com/en-us/library/aa364962%28VS.85%29.aspx
+        [DllImport("kernel32.dll", EntryPoint = "GetFinalPathNameByHandleW", CharSet = CharSet.Unicode,
+            SetLastError = true)]
+        public static extern int GetFinalPathNameByHandle(IntPtr handle,
+            [In, Out] StringBuilder path,
+            int bufLen,
+            int flags);
+
+        // http://msdn.microsoft.com/en-us/library/aa363858(VS.85).aspx
+        [DllImport("kernel32.dll", EntryPoint = "CreateFileW", CharSet = CharSet.Unicode, SetLastError = true)]
+        public static extern SafeFileHandle CreateFile(string lpFileName,
+            int dwDesiredAccess,
+            int dwShareMode,
+            IntPtr SecurityAttributes,
+            int dwCreationDisposition,
+            int dwFlagsAndAttributes,
+            IntPtr hTemplateFile);
+
+        public static string GetSymbolicLinkTarget(FileInfo symlink)
+        {
+            var fileHandle = CreateFile(symlink.FullName, 0, 2, IntPtr.Zero, CREATION_DISPOSITION_OPEN_EXISTING,
+                FILE_FLAG_BACKUP_SEMANTICS, IntPtr.Zero);
+            if (fileHandle.IsInvalid)
+            {
+                throw new Win32Exception(Marshal.GetLastWin32Error());
+            }
+
+            var path = new StringBuilder(512);
+            var size = GetFinalPathNameByHandle(fileHandle.DangerousGetHandle(), path, path.Capacity, 0);
+            if (size < 0)
+            {
+                throw new Win32Exception(Marshal.GetLastWin32Error());
+            }
+            // The remarks section of GetFinalPathNameByHandle mentions the return being prefixed with "\\?\"
+            // More information about "\\?\" here -> http://msdn.microsoft.com/en-us/library/aa365247(v=VS.85).aspx
+            if (path[0] == '\\' && path[1] == '\\' && path[2] == '?' && path[3] == '\\')
+            {
+                return path.ToString().Substring(4);
+            }
+            return path.ToString();
+        }
+    }
+}

WitcherScriptMerger/Tools/KDiff3.cs

@@ -32,8 +32,12 @@ public static int Run(
                 ? "\"" + vanillaFile.FullName + "\" "
                 : "");
 
+            // resolve any simlinked files
+            var source1FullName = source1.TextFile.ResolveTargetFileFullName();
+            var source2FullName = source2.TextFile.ResolveTargetFileFullName();
+
             args +=
-                $"\"{source1.TextFile.FullName}\" \"{source2.TextFile.FullName}\" " +
+                $"\"{source1FullName}\" \"{source2FullName}\" " +
                 $"-o \"{outputPath}\" " +
                 "--cs \"WhiteSpace3FileMergeDefault=2\" " +
                 "--cs \"CreateBakFiles=0\" " +
@@ -51,7 +55,7 @@ public static int Run(
 
             if (!Program.Settings.Get<bool>("ReviewEachMerge") && hasVanillaVersion)
             {
-                if (source1.TextFile.FullName.EqualsIgnoreCase(outputPath)
+                if (source1FullName.EqualsIgnoreCase(outputPath)
                     && source2.Hash != null && source2.Hash.IsOutdated)
                 {
                     Program.MainForm.ShowMessage(

WitcherScriptMerger/WitcherScriptMerger.csproj

@@ -69,6 +69,7 @@
     <Compile Include="Forms\OptionsForm.Designer.cs">
       <DependentUpon>OptionsForm.cs</DependentUpon>
     </Compile>
+    <Compile Include="SimLink.cs" />
     <Compile Include="Tools\xxHash.cs" />
     <Compile Include="FileIndex\ModFile.cs" />
     <Compile Include="FileIndex\ModFileCategory.cs" />