Merge pull request #1103 from DmitryZhelnin/fix827

fix GitCommitDate being author date rather than commit date

Author: AArnott

src/NerdBank.GitVersioning/DisabledGit/DisabledGitContext.cs

@@ -24,6 +24,8 @@ public DisabledGitContext(string workingTreePath)
 
     public override DateTimeOffset? GitCommitDate => null;
 
+    public override DateTimeOffset? GitCommitAuthorDate => null;
+
     public override string? HeadCanonicalName => null;
 
     public override IReadOnlyCollection<string>? HeadTags => null;

src/NerdBank.GitVersioning/GitContext.cs

@@ -113,6 +113,11 @@ public string RepoRelativeProjectDirectory
     /// </summary>
     public abstract DateTimeOffset? GitCommitDate { get; }
 
+    /// <summary>
+    /// Gets the date that the commit identified by <see cref="GitCommitId"/> was authored.
+    /// </summary>
+    public abstract DateTimeOffset? GitCommitAuthorDate { get; }
+
     /// <summary>
     /// Gets the canonical name for HEAD's position (e.g. <c>refs/heads/main</c>).
     /// </summary>

src/NerdBank.GitVersioning/LibGit2/LibGit2Context.cs

@@ -51,7 +51,10 @@ internal LibGit2Context(string workingTreeDirectory, string dotGitPath, string?
     public override bool IsHead => this.Repository.Head?.Tip?.Equals(this.Commit) ?? false;
 
     /// <inheritdoc />
-    public override DateTimeOffset? GitCommitDate => this.Commit?.Author.When;
+    public override DateTimeOffset? GitCommitDate => this.Commit?.Committer.When;
+
+    /// <inheritdoc />
+    public override DateTimeOffset? GitCommitAuthorDate => this.Commit?.Author.When;
 
     /// <inheritdoc />
     public override string HeadCanonicalName => this.Repository.Head.CanonicalName;

src/NerdBank.GitVersioning/Managed/ManagedGitContext.cs

@@ -53,7 +53,10 @@ internal ManagedGitContext(string workingDirectory, string dotGitPath, string? c
     public override bool IsHead => this.Repository.GetHeadCommit().Equals(this.Commit);
 
     /// <inheritdoc />
-    public override DateTimeOffset? GitCommitDate => this.Commit is { } commit ? (commit.Author?.Date ?? this.Repository.GetCommit(commit.Sha, readAuthor: true).Author?.Date) : null;
+    public override DateTimeOffset? GitCommitDate => this.Commit is { } commit ? (commit.Committer?.Date ?? this.Repository.GetCommit(commit.Sha, readAuthor: true).Committer?.Date) : null;
+
+    /// <inheritdoc />
+    public override DateTimeOffset? GitCommitAuthorDate => this.Commit is { } commit ? (commit.Author?.Date ?? this.Repository.GetCommit(commit.Sha, readAuthor: true).Author?.Date) : null;
 
     /// <inheritdoc />
     public override string HeadCanonicalName => this.Repository.GetHeadAsReferenceOrSha().ToString() ?? throw new InvalidOperationException("Unable to determine the HEAD position.");

src/NerdBank.GitVersioning/ManagedGit/GitCommit.cs

@@ -48,6 +48,11 @@ public struct GitCommit : IEquatable<GitCommit>
     /// </summary>
     public GitSignature? Author { get; set; }
 
+    /// <summary>
+    /// Gets or sets the committer of this commit.
+    /// </summary>
+    public GitSignature? Committer { get; set; }
+
     public static bool operator ==(GitCommit left, GitCommit right)
     {
         return Equals(left, right);

src/NerdBank.GitVersioning/ManagedGit/GitCommitReader.cs

@@ -19,6 +19,7 @@ public static class GitCommitReader
     private static readonly byte[] TreeStart = GitRepository.Encoding.GetBytes("tree ");
     private static readonly byte[] ParentStart = GitRepository.Encoding.GetBytes("parent ");
     private static readonly byte[] AuthorStart = GitRepository.Encoding.GetBytes("author ");
+    private static readonly byte[] CommitterStart = GitRepository.Encoding.GetBytes("committer ");
 
     /// <summary>
     /// Reads a <see cref="GitCommit"/> object from a <see cref="Stream"/>.
@@ -30,7 +31,7 @@ public static class GitCommitReader
     /// The <see cref="GitObjectId"/> of the commit.
     /// </param>
     /// <param name="readAuthor">
-    /// A value indicating whether to populate the <see cref="GitCommit.Author"/> field.
+    /// A value indicating whether to populate the <see cref="GitCommit.Author"/> and <see cref="GitCommit.Committer"/> fields.
     /// </param>
     /// <returns>
     /// The <see cref="GitCommit"/>.
@@ -67,7 +68,7 @@ public static GitCommit Read(Stream stream, GitObjectId sha, bool readAuthor = f
     /// The <see cref="GitObjectId"/> of the commit.
     /// </param>
     /// <param name="readAuthor">
-    /// A value indicating whether to populate the <see cref="GitCommit.Author"/> field.
+    /// A value indicating whether to populate the <see cref="GitCommit.Author"/> and <see cref="GitCommit.Committer"/> fields.
     /// </param>
     /// <returns>
     /// The <see cref="GitCommit"/>.
@@ -102,11 +103,22 @@ public static GitCommit Read(ReadOnlySpan<byte> commit, GitObjectId sha, bool re
             buffer = buffer.Slice(ParentLineLength);
         }
 
-        GitSignature signature = default;
+        GitSignature author = default;
+        GitSignature committer = default;
 
-        if (readAuthor && !TryReadAuthor(buffer, out signature))
+        if (readAuthor)
         {
-            throw new GitException();
+            if (!TryReadAuthor(buffer, out author, out int lineLength))
+            {
+                throw new GitException();
+            }
+
+            buffer = buffer.Slice(lineLength);
+
+            if (!TryReadCommitter(buffer, out committer))
+            {
+                throw new GitException();
+            }
         }
 
         return new GitCommit()
@@ -116,7 +128,8 @@ public static GitCommit Read(ReadOnlySpan<byte> commit, GitObjectId sha, bool re
             SecondParent = secondParent,
             AdditionalParents = additionalParents,
             Tree = tree,
-            Author = readAuthor ? signature : null,
+            Author = readAuthor ? author : null,
+            Committer = readAuthor ? committer : null,
         };
     }
 
@@ -153,16 +166,27 @@ private static bool TryReadParent(ReadOnlySpan<byte> line, out GitObjectId paren
         return true;
     }
 
-    private static bool TryReadAuthor(ReadOnlySpan<byte> line, out GitSignature signature)
+    private static bool TryReadAuthor(ReadOnlySpan<byte> line, out GitSignature signature, out int lineLength)
+    {
+        return TryReadSignature(line, AuthorStart, out signature, out lineLength);
+    }
+
+    private static bool TryReadCommitter(ReadOnlySpan<byte> line, out GitSignature signature)
+    {
+        return TryReadSignature(line, CommitterStart, out signature, out _);
+    }
+
+    private static bool TryReadSignature(ReadOnlySpan<byte> line, byte[] signatureStart, out GitSignature signature, out int lineLength)
     {
         signature = default;
+        lineLength = default;
 
-        if (!line.Slice(0, AuthorStart.Length).SequenceEqual(AuthorStart))
+        if (!line.Slice(0, signatureStart.Length).SequenceEqual(signatureStart))
         {
             return false;
         }
 
-        line = line.Slice(AuthorStart.Length);
+        line = line.Slice(signatureStart.Length);
 
         int emailStart = line.IndexOf((byte)'<');
         int emailEnd = line.IndexOf((byte)'>');
@@ -179,6 +203,7 @@ private static bool TryReadAuthor(ReadOnlySpan<byte> line, out GitSignature sign
         long ticks = long.Parse(GitRepository.GetString(time.Slice(0, offsetStart)));
         signature.Date = DateTimeOffset.FromUnixTimeSeconds(ticks);
 
+        lineLength = signatureStart.Length + lineEnd + 1;
         return true;
     }
 }

src/NerdBank.GitVersioning/ManagedGit/GitRepository.cs

@@ -296,7 +296,7 @@ public GitObjectId GetHeadCommitSha()
     /// Gets the current HEAD commit, if available.
     /// </summary>
     /// <param name="readAuthor">
-    /// A value indicating whether to populate the <see cref="GitCommit.Author"/> field.
+    /// A value indicating whether to populate the <see cref="GitCommit.Author"/> and <see cref="GitCommit.Committer"/> fields.
     /// </param>
     /// <returns>
     /// The current HEAD commit, or <see langword="null"/> if not available.
@@ -320,7 +320,7 @@ public GitObjectId GetHeadCommitSha()
     /// The Git object Id of the commit.
     /// </param>
     /// <param name="readAuthor">
-    /// A value indicating whether to populate the <see cref="GitCommit.Author"/> field.
+    /// A value indicating whether to populate the <see cref="GitCommit.Author"/> and <see cref="GitCommit.Committer"/> fields.
     /// </param>
     /// <returns>
     /// The requested commit.

src/NerdBank.GitVersioning/NoGit/NoGitContext.cs

@@ -30,6 +30,8 @@ public NoGitContext(string workingTreePath)
     /// <inheritdoc/>
     public override DateTimeOffset? GitCommitDate => null;
 
+    public override DateTimeOffset? GitCommitAuthorDate => null;
+
     /// <inheritdoc/>
     public override string? HeadCanonicalName => null;
 

src/NerdBank.GitVersioning/VersionOracle.cs

@@ -265,6 +265,11 @@ public IEnumerable<string> BuildMetadataWithCommitId
     /// </summary>
     public DateTimeOffset? GitCommitDate => this.context.GitCommitDate;
 
+    /// <summary>
+    /// Gets the Git revision control commit author date for HEAD (the current source code version).
+    /// </summary>
+    public DateTimeOffset? GitCommitAuthorDate => this.context.GitCommitAuthorDate;
+
     /// <summary>
     /// Gets or sets the number of commits in the longest single path between
     /// the specified commit and the most distant ancestor (inclusive)

src/Nerdbank.GitVersioning.Tasks/AssemblyVersionInfo.cs

@@ -91,6 +91,8 @@ the code is regenerated.
 
         public string GitCommitDateTicks { get; set; }
 
+        public string GitCommitAuthorDateTicks { get; set; }
+
         public bool EmitThisAssemblyClass { get; set; } = true;
 
         /// <summary>
@@ -440,6 +442,11 @@ private void GenerateAssemblyAttributes()
                 fields.Add("GitCommitDate", (new DateTime(gitCommitDateTicks, DateTimeKind.Utc), true));
             }
 
+            if (long.TryParse(this.GitCommitAuthorDateTicks, out long gitCommitAuthorDateTicks))
+            {
+                fields.Add("GitCommitAuthorDate", (new DateTime(gitCommitAuthorDateTicks, DateTimeKind.Utc), true));
+            }
+
             if (this.AdditionalThisAssemblyFields is object)
             {
                 foreach (ITaskItem item in this.AdditionalThisAssemblyFields)