FullPathResolver: Avoid exception for illegal characters

GitCommands/FileAssociatedIconProvider.cs

@@ -51,7 +51,7 @@ public FileAssociatedIconProvider()
         /// </remarks>
         public Icon Get(string workingDirectory, string relativeFilePath)
         {
-            var extension = Path.GetExtension(relativeFilePath);
+            var extension = PathUtil.GetExtension(relativeFilePath);
             if (string.IsNullOrWhiteSpace(extension))
             {
                 return null;
@@ -68,7 +68,7 @@ public Icon Get(string workingDirectory, string relativeFilePath)
                     // extensions from the registry and using p/invokes and WinAPI, which have
                     // significantly higher maintenance overhead.
 
-                    var fullPath = Path.Combine(workingDirectory, relativeFilePath);
+                    var fullPath = PathUtil.Combine(workingDirectory, relativeFilePath);
                     if (!_fileSystem.File.Exists(fullPath))
                     {
                         tempFile = CreateTempFile(Path.GetFileName(fullPath));
@@ -117,4 +117,4 @@ internal void ResetCache()
             LoadedFileIcons.Clear();
         }
     }
-}
+}

GitCommands/FullPathResolver.cs

@@ -32,6 +32,11 @@ public FullPathResolver(Func<string> getWorkingDir)
         /// <summary>
         /// Resolves the provided path (folder or file) against the current working directory.
         /// </summary>
+        /// <remarks>
+        /// Behaves similar to the .NET Core 2.1 version that do not throw on paths with illegal
+        /// Windows characters (that could be OK in Git paths or for cross platform) but returns
+        /// null instead of an possible path.
+        /// but </remarks>
         /// <param name="path">Folder or file path to resolve.</param>
         /// <returns>
         /// <paramref name="path" /> if <paramref name="path" /> is rooted; otherwise resolved path from working directory of the current repository.
@@ -41,12 +46,21 @@ public string Resolve(string path)
         {
             if (string.IsNullOrWhiteSpace(path))
             {
-                throw new ArgumentNullException(nameof(path));
+                return null;
             }
 
-            if (Path.IsPathRooted(path))
+            try
             {
-                return path;
+                if (Path.IsPathRooted(path))
+                {
+                    return path;
+                }
+            }
+            catch (ArgumentException)
+            {
+                // Illegal characters in path.
+                // This is used for Git paths that may not be possible in the host file system
+                return null;
             }
 
             var workingDir = _getWorkingDir();

GitCommands/Git/GitItemStatusFileExtensionComparer.cs

@@ -28,8 +28,8 @@ public override int Compare(GitItemStatus x, GitItemStatus y)
 
             var lhsPath = GetPrimarySortingPath(x);
             var rhsPath = GetPrimarySortingPath(y);
-            var lhsExt = Path.GetExtension(lhsPath);
-            var rhsExt = Path.GetExtension(rhsPath);
+            var lhsExt = PathUtil.GetExtension(lhsPath);
+            var rhsExt = PathUtil.GetExtension(rhsPath);
 
             var comparisonResult = StringComparer.InvariantCulture.Compare(lhsExt, rhsExt);
             if (comparisonResult == 0)

GitCommands/GitRevisionInfoProvider.cs

@@ -59,9 +59,7 @@ IEnumerable<IGitItem> YieldSubItems()
                 {
                     if (subItem is GitItem gitItem)
                     {
-                        gitItem.FileName = Path.Combine(
-                            basePath,
-                            gitItem.FileName ?? string.Empty);
+                        gitItem.FileName = PathUtil.Combine(basePath, gitItem.FileName) ?? string.Empty;
                     }
 
                     yield return subItem;

GitCommands/PathUtil.cs

@@ -132,6 +132,54 @@ public static string NormalizePath([NotNull] this string path)
             }
         }
 
+        /// <summary>
+        /// Wrapper for Path.Combine
+        /// </summary>
+        /// <remark>
+        /// Similar to the .NET Core 2.1 variant, except that null is returned if Windows
+        /// invalid characters (that may be accepted in Git or other filesystems)
+        /// are in the paths instead of a possible path (the OS or file system will throw
+        /// if the paths are invalid).
+        /// </remark>
+        /// <param name="path1">initial part</param>
+        /// <param name="path2">second part</param>
+        /// <returns>path if it can be combined, null otherwise</returns>
+        [CanBeNull]
+        public static string Combine(string path1, string path2)
+        {
+            try
+            {
+                return Path.Combine(path1, path2);
+            }
+            catch (ArgumentException)
+            {
+                return null;
+            }
+        }
+
+        /// <summary>
+        /// Wrapper for Path.GetExtension
+        /// </summary>
+        /// <remark>
+        /// <see cref="Combine"/> for motivation.
+        /// </remark>
+        /// <param name="path">path to check</param>
+        /// <returns>path if it can be combined, empty otherwise</returns>
+        [NotNull]
+        public static string GetExtension(string path)
+        {
+            try
+            {
+                return Path.GetExtension(path);
+            }
+            catch (ArgumentException)
+            {
+                // This could return part after a '.' using string commands,
+                // but wait for .NET Core with this edge case
+                return string.Empty;
+            }
+        }
+
         [NotNull]
         public static string Resolve([NotNull] string path, string relativePath = "")
         {
@@ -223,7 +271,7 @@ public static bool TryFindFullPath([NotNull] string fileName, out string fullPat
 
                 foreach (var path in EnvironmentPathsProvider.GetEnvironmentValidPaths())
                 {
-                    fullPath = Path.Combine(path, fileName);
+                    fullPath = Combine(path, fileName);
                     if (File.Exists(fullPath))
                     {
                         return true;
@@ -251,7 +299,7 @@ public static bool TryFindShellPath([NotNull] string shell, out string shellPath
                     return true;
                 }
 
-                shellPath = Path.Combine(AppSettings.GitBinDir, shell);
+                shellPath = Combine(AppSettings.GitBinDir, shell);
                 if (File.Exists(shellPath))
                 {
                     return true;
@@ -369,7 +417,7 @@ string FindFileInEnvVarFolder(string environmentVariable, string location, strin
                     return null;
                 }
 
-                var path = Path.Combine(envVarFolder, location);
+                var path = Combine(envVarFolder, location);
                 if (!Directory.Exists(path))
                 {
                     return null;
@@ -380,7 +428,7 @@ string FindFileInEnvVarFolder(string environmentVariable, string location, strin
 
             string FindFile(string location, string fileName1)
             {
-                string fullName = Path.Combine(location, fileName1);
+                string fullName = Combine(location, fileName1);
                 if (File.Exists(fullName))
                 {
                     return fullName;

GitCommands/StringExtensions.cs

@@ -179,18 +179,18 @@ public static string Combine([CanBeNull] this string left, [NotNull] string sep,
         }
 
         /// <summary>
-        /// Quotes this string with the specified <paramref name="quotationMark"/>
+        /// Quotes this string with the specified <paramref name="q"/>
         /// </summary>
         [Pure]
         [NotNull]
-        public static string Quote([CanBeNull] this string s, [NotNull] string quotationMark = "\"")
+        public static string Quote([CanBeNull] this string s, [NotNull] string q = "\"")
         {
             if (s == null)
             {
                 return "";
             }
 
-            return quotationMark + s + quotationMark;
+            return $"{q}{s.Replace(q, "\\" + q)}{q}";
         }
 
         /// <summary>

GitUI/AutoCompletion/CommitAutoCompleteProvider.cs

@@ -41,7 +41,7 @@ public async Task<IEnumerable<AutoCompleteWord>> GetAutoCompleteWordsAsync(Cance
             {
                 cancellationToken.ThrowIfCancellationRequested();
 
-                var regex = GetRegexForExtension(Path.GetExtension(file.Name));
+                var regex = GetRegexForExtension(PathUtil.GetExtension(file.Name));
 
                 if (regex != null)
                 {
@@ -94,7 +94,7 @@ private static Regex GetRegexForExtension(string extension)
 
         private static IEnumerable<string> ReadOrInitializeAutoCompleteRegexes()
         {
-            var path = Path.Combine(AppSettings.ApplicationDataPath.Value, "AutoCompleteRegexes.txt");
+            var path = PathUtil.Combine(AppSettings.ApplicationDataPath.Value, "AutoCompleteRegexes.txt");
 
             if (File.Exists(path))
             {

GitUI/CommandsDialogs/FormBrowse.cs

@@ -2015,14 +2015,20 @@ public static void CopyFullPathToClipboard(FileStatusList diffFiles, GitModule m
             var fileNames = new StringBuilder();
             foreach (var item in diffFiles.SelectedItems)
             {
+                var path = PathUtil.Combine(module.WorkingDir, item.Item.Name);
+                if (string.IsNullOrWhiteSpace(path))
+                {
+                    continue;
+                }
+
                 // Only use append line when multiple items are selected.
                 // This to make it easier to use the text from clipboard when 1 file is selected.
                 if (fileNames.Length > 0)
                 {
                     fileNames.AppendLine();
                 }
 
-                fileNames.Append(Path.Combine(module.WorkingDir, item.Item.Name).ToNativePath());
+                fileNames.Append(path.ToNativePath());
             }
 
             ClipboardUtil.TrySetText(fileNames.ToString());
@@ -2423,7 +2429,12 @@ public static void OpenContainingFolder(FileStatusList diffFiles, GitModule modu
 
             foreach (var item in diffFiles.SelectedItems)
             {
-                string filePath = Path.Combine(module.WorkingDir, item.Item.Name.ToNativePath());
+                string filePath = PathUtil.Combine(module.WorkingDir, item.Item.Name.ToNativePath());
+                if (string.IsNullOrWhiteSpace(filePath))
+                {
+                    continue;
+                }
+
                 FormBrowseUtil.ShowFileOrParentFolderInFileExplorer(filePath);
             }
         }

GitUI/CommandsDialogs/FormCommit.cs

@@ -2598,14 +2598,20 @@ private void FilenameToClipboardToolStripMenuItemClick(object sender, EventArgs
             var fileNames = new StringBuilder();
             foreach (var item in list.SelectedItems)
             {
+                var fileName = _fullPathResolver.Resolve(item.Item.Name);
+                if (string.IsNullOrWhiteSpace(fileName))
+                {
+                    continue;
+                }
+
                 // Only use append line when multiple items are selected.
                 // This to make it easier to use the text from clipboard when 1 file is selected.
                 if (fileNames.Length > 0)
                 {
                     fileNames.AppendLine();
                 }
 
-                fileNames.Append(_fullPathResolver.Resolve(item.Item.Name).ToNativePath());
+                fileNames.Append(fileName.ToNativePath());
             }
 
             ClipboardUtil.TrySetText(fileNames.ToString());
@@ -2700,12 +2706,17 @@ private void editFileToolStripMenuItem_Click(object sender, EventArgs e)
             }
 
             var item = list.SelectedGitItem;
-            if (item == null)
+            if (item is null)
             {
                 return;
             }
 
             var fileName = _fullPathResolver.Resolve(item.Name);
+            if (string.IsNullOrWhiteSpace(fileName))
+            {
+                return;
+            }
+
             UICommands.StartFileEditorDialog(fileName);
 
             UnstagedSelectionChanged(null, null);
@@ -3184,13 +3195,10 @@ private void OpenContainingFolder(FileStatusList list)
         {
             foreach (var item in list.SelectedItems)
             {
-                var fileNames = new StringBuilder();
-                fileNames.Append(_fullPathResolver.Resolve(item.Item.Name).ToNativePath());
-
-                string filePath = fileNames.ToString();
+                string filePath = _fullPathResolver.Resolve(item.Item.Name);
                 if (File.Exists(filePath))
                 {
-                    OsShellUtil.SelectPathInFileExplorer(filePath);
+                    OsShellUtil.SelectPathInFileExplorer(filePath.ToNativePath());
                 }
             }
         }

GitUI/CommandsDialogs/FormFileHistory.cs

@@ -446,8 +446,13 @@ private void saveAsToolStripMenuItem_Click(object sender, EventArgs e)
                     orgFileName = FileName;
                 }
 
-                string fullName = _fullPathResolver.Resolve(orgFileName.ToNativePath());
+                string fullName = _fullPathResolver.Resolve(orgFileName);
+                if (string.IsNullOrWhiteSpace(fullName))
+                {
+                    return;
+                }
 
+                fullName = fullName.ToNativePath();
                 using (var fileDialog = new SaveFileDialog
                 {
                     InitialDirectory = Path.GetDirectoryName(fullName),