Merge pull request #1334 from dotnet/better-case-insensitivity

Fix case insensitivity for the managed engine on git worktrees, and implement for libgit2

Author: AArnott

src/NerdBank.GitVersioning/LibGit2/LibGit2VersionFile.cs

@@ -37,7 +37,7 @@ internal LibGit2VersionFile(LibGit2Context context)
     /// <returns>The version information read from the file.</returns>
     internal VersionOptions? GetVersion(Commit commit, string repoRelativeProjectDirectory, Dictionary<ObjectId, VersionOptions?>? blobVersionCache, VersionFileRequirements requirements, out VersionFileLocations locations)
     {
-        repoRelativeProjectDirectory = TrimTrailingPathSeparator(repoRelativeProjectDirectory);
+        repoRelativeProjectDirectory = this.NormalizeTreeDirectoryPath(commit, TrimTrailingPathSeparator(repoRelativeProjectDirectory));
         locations = default;
 
         string? searchDirectory = repoRelativeProjectDirectory ?? string.Empty;
@@ -153,4 +153,36 @@ internal LibGit2VersionFile(LibGit2Context context)
 
     /// <inheritdoc/>
     protected override VersionOptions? GetVersionCore(VersionFileRequirements requirements, out VersionFileLocations locations) => this.GetVersion(this.Context.Commit!, this.Context.RepoRelativeProjectDirectory, null, requirements, out locations);
+
+    private string NormalizeTreeDirectoryPath(Commit commit, string repoRelativeProjectDirectory)
+    {
+        if (string.IsNullOrEmpty(repoRelativeProjectDirectory) || !this.IsIgnoreCaseEnabled())
+        {
+            return repoRelativeProjectDirectory;
+        }
+
+        Tree currentTree = commit.Tree;
+        string[] pathSegments = repoRelativeProjectDirectory.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);
+        var resolvedSegments = new List<string>(pathSegments.Length);
+
+        foreach (string segment in pathSegments)
+        {
+            TreeEntry? entry = currentTree[segment] ?? currentTree.FirstOrDefault(candidate => string.Equals(candidate.Name, segment, StringComparison.OrdinalIgnoreCase));
+            if (entry?.TargetType != TreeEntryTargetType.Tree || entry.Target is not Tree childTree)
+            {
+                return repoRelativeProjectDirectory;
+            }
+
+            resolvedSegments.Add(entry.Name);
+            currentTree = childTree;
+        }
+
+        return string.Join("/", resolvedSegments);
+    }
+
+    private bool IsIgnoreCaseEnabled()
+    {
+        ConfigurationEntry<bool>? ignoreCaseSetting = this.Context.Repository.Config.Get<bool>("core.ignorecase");
+        return ignoreCaseSetting?.Value ?? false;
+    }
 }

src/NerdBank.GitVersioning/ManagedGit/GitRepository.cs

@@ -866,11 +866,17 @@ private bool ReadIgnoreCaseFromConfig()
     {
         try
         {
-            // Try to read from .git/config first (repository-specific)
-            string repoConfigPath = Path.Combine(this.GitDirectory, "config");
-            if (File.Exists(repoConfigPath))
+            string[] configPaths = this.GitDirectory == this.CommonDirectory
+                ? new[] { Path.Combine(this.CommonDirectory, "config") }
+                : new[]
+                {
+                    Path.Combine(this.CommonDirectory, "config"),
+                    Path.Combine(this.GitDirectory, "config"),
+                };
+
+            foreach (string repoConfigPath in configPaths)
             {
-                if (TryReadIgnoreCaseFromConfigFile(repoConfigPath, out bool ignoreCase))
+                if (File.Exists(repoConfigPath) && TryReadIgnoreCaseFromConfigFile(repoConfigPath, out bool ignoreCase))
                 {
                     return ignoreCase;
                 }

test/Nerdbank.GitVersioning.Tests/VersionFileTests.cs

@@ -696,20 +696,10 @@ public void GetVersion_CaseInsensitivePathMatching()
         // to case-insensitive matching
         VersionOptions actualVersionOptionsWithDifferentCase = this.GetVersionOptions("myproject");
 
-        // This should also find the version file despite the case difference
-        // NOTE: This currently only works for the managed implementation, not LibGit2
-        if (this is VersionFileManagedTests)
-        {
-            Assert.NotNull(actualVersionOptionsWithDifferentCase);
-            Assert.Equal("1.2.3", actualVersionOptionsWithDifferentCase.Version.ToString());
-            Assert.Equal(10, actualVersionOptionsWithDifferentCase.VersionHeightOffset);
-        }
-        else
-        {
-            // LibGit2 implementation doesn't yet support case-insensitive fallback
-            // This test documents the current limitation
-            Assert.Null(actualVersionOptionsWithDifferentCase);
-        }
+        // This should also find the version file despite the case difference.
+        Assert.NotNull(actualVersionOptionsWithDifferentCase);
+        Assert.Equal("1.2.3", actualVersionOptionsWithDifferentCase.Version.ToString());
+        Assert.Equal(10, actualVersionOptionsWithDifferentCase.VersionHeightOffset);
     }
 
     [Fact]