fix GitCommitDate being author date rather than commit date

Author: Dmitry Zhelnin

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)

src/Nerdbank.GitVersioning.Tasks/GetBuildVersion.cs

@@ -165,6 +165,13 @@ public GetBuildVersion()
         [Output]
         public string GitCommitDateTicks { get; private set; }
 
+        /// <summary>
+        /// Gets the Git revision control commit author date for HEAD (the current source code version), expressed as the number of 100-nanosecond
+        /// intervals that have elapsed since January 1, 0001 at 00:00:00.000 in the Gregorian calendar.
+        /// </summary>
+        [Output]
+        public string GitCommitAuthorDateTicks { get; private set; }
+
         /// <summary>
         /// Gets the number of commits in the longest single path between
         /// the specified commit and the most distant ancestor (inclusive)
@@ -266,6 +273,7 @@ protected override bool ExecuteInner()
                 this.GitCommitId = oracle.GitCommitId;
                 this.GitCommitIdShort = oracle.GitCommitIdShort;
                 this.GitCommitDateTicks = oracle.GitCommitDate is not null ? oracle.GitCommitDate.Value.UtcTicks.ToString(CultureInfo.InvariantCulture) : null;
+                this.GitCommitAuthorDateTicks = oracle.GitCommitAuthorDate is not null ? oracle.GitCommitAuthorDate.Value.UtcTicks.ToString(CultureInfo.InvariantCulture) : null;
                 this.GitVersionHeight = oracle.VersionHeight;
                 this.BuildMetadataFragment = oracle.BuildMetadataFragment;
                 this.CloudBuildNumber = oracle.CloudBuildNumberEnabled ? oracle.CloudBuildNumber : null;
@@ -314,6 +322,7 @@ protected override bool ExecuteInner()
                     { "GitCommitId", this.GitCommitId },
                     { "GitCommitIdShort", this.GitCommitIdShort },
                     { "GitCommitDateTicks", this.GitCommitDateTicks },
+                    { "GitCommitAuthorDateTicks", this.GitCommitAuthorDateTicks },
                     { "GitVersionHeight", this.GitVersionHeight.ToString(CultureInfo.InvariantCulture) },
                     { "BuildNumber", this.BuildNumber.ToString(CultureInfo.InvariantCulture) },
                     { "BuildVersionNumberComponent", this.BuildNumber.ToString(CultureInfo.InvariantCulture) },

src/Nerdbank.GitVersioning.Tasks/build/Nerdbank.GitVersioning.targets

@@ -169,6 +169,7 @@
                   PrereleaseVersion="$(PrereleaseVersion)"
                   GitCommitId="$(GitCommitId)"
                   GitCommitDateTicks="$(GitCommitDateTicks)"
+                  GitCommitAuthorDateTicks="$(GitCommitAuthorDateTicks)"
                   EmitNonVersionCustomAttributes="$(NBGV_EmitNonVersionCustomAttributes)"
                   EmitThisAssemblyClass="$(NBGV_EmitThisAssemblyClass)"
                   AdditionalThisAssemblyFields="@(AdditionalThisAssemblyFields)"

test/Nerdbank.GitVersioning.Tests/BuildIntegrationTests.cs

@@ -304,7 +304,8 @@ protected void AssertStandardProperties(VersionOptions versionOptions, BuildResu
         Assert.Equal(idAsVersion.Build.ToString(), buildResult.BuildVersionNumberComponent);
         Assert.Equal($"{idAsVersion.Major}.{idAsVersion.Minor}.{idAsVersion.Build}", buildResult.BuildVersionSimple);
         Assert.Equal(this.LibGit2Repository.Head.Tip.Id.Sha, buildResult.GitCommitId);
-        Assert.Equal(this.LibGit2Repository.Head.Tip.Author.When.UtcTicks.ToString(CultureInfo.InvariantCulture), buildResult.GitCommitDateTicks);
+        Assert.Equal(this.LibGit2Repository.Head.Tip.Committer.When.UtcTicks.ToString(CultureInfo.InvariantCulture), buildResult.GitCommitDateTicks);
+        Assert.Equal(this.LibGit2Repository.Head.Tip.Author.When.UtcTicks.ToString(CultureInfo.InvariantCulture), buildResult.GitCommitAuthorDateTicks);
         Assert.Equal(commitIdShort, buildResult.GitCommitIdShort);
         Assert.Equal(versionHeight.ToString(), buildResult.GitVersionHeight);
         Assert.Equal($"{version.Major}.{version.Minor}", buildResult.MajorMinorVersion);
@@ -558,6 +559,8 @@ internal BuildResults(BuildResult buildResult, IReadOnlyList<BuildEventArgs> log
 
         public string GitCommitDateTicks => this.BuildResult.ProjectStateAfterBuild.GetPropertyValue("GitCommitDateTicks");
 
+        public string GitCommitAuthorDateTicks => this.BuildResult.ProjectStateAfterBuild.GetPropertyValue("GitCommitAuthorDateTicks");
+
         public string GitVersionHeight => this.BuildResult.ProjectStateAfterBuild.GetPropertyValue("GitVersionHeight");
 
         public string SemVerBuildSuffix => this.BuildResult.ProjectStateAfterBuild.GetPropertyValue("SemVerBuildSuffix");

test/Nerdbank.GitVersioning.Tests/ManagedGit/GitCommitReaderTests.cs

@@ -32,7 +32,11 @@ public void ReadTest()
             Assert.Equal(new DateTimeOffset(2020, 10, 6, 13, 40, 09, TimeSpan.FromHours(-6)), author.Date);
             Assert.Equal("[email protected]", author.Email);
 
-            // Committer and commit message are not read
+            GitSignature committer = commit.Committer.Value;
+
+            Assert.Equal("Andrew Arnott", committer.Name);
+            Assert.Equal(new DateTimeOffset(2020, 10, 6, 14, 40, 09, TimeSpan.FromHours(-6)), committer.Date);
+            Assert.Equal("[email protected]", committer.Email);
         }
     }
 

test/Nerdbank.GitVersioning.Tests/ManagedGit/commit-4497b0eaaa89abf0e6d70961ad5f04fd3a49cbc6

@@ -1,6 +1,6 @@
 tree f914b48023c7c804a4f3be780d451f31aef74ac1
 parent 06cc627f28736c0d13506b0414126580fe37c6f3
 author Andrew Arnott <[email protected]> 1602013209 -0600
-committer Andrew Arnott <[email protected]> 1602013209 -0600
+committer Andrew Arnott <[email protected]> 1602016809 -0600
 
 Set version to '3.4-alpha'

test/Nerdbank.GitVersioning.Tests/ManagedGit/commit-d56dc3ed179053abef2097d1120b4507769bcf1a

@@ -2,6 +2,6 @@ tree f914b48023c7c804a4f3be780d451f31aef74ac1
 parent 4497b0eaaa89abf0e6d70961ad5f04fd3a49cbc6
 parent 0989e8fe0cd0e0900173b26decdfb24bc0cc8232
 author Andrew Arnott <[email protected]> 1602013209 -0600
-committer Andrew Arnott <[email protected]> 1602013209 -0600
+committer Andrew Arnott <[email protected]> 1602016809 -0600
 
 Merge branch 'v3.3'