GitVersion calculates the wrong version after main is merged back to develop

src/GitVersion.Core.Tests/IntegrationTests/OtherScenarios.cs

@@ -1218,4 +1218,87 @@ public void EnsurePreventIncrementWhenCurrentCommitTaggedOnReleaseBranchAndIncre
 
         fixture.AssertFullSemver(semVersion, configuration);
     }
+
+    [Test]
+    public void EnsureVersionAfterMainIsMergedBackToDevelopIsCorrect()
+    {
+        using EmptyRepositoryFixture fixture = new("main");
+
+        fixture.MakeATaggedCommit("1.0.0");
+        fixture.BranchTo("develop");
+        fixture.MakeACommit("A");
+
+        // ✅ succeeds as expected
+        fixture.AssertFullSemver("1.1.0-alpha.1");
+
+        fixture.Checkout("main");
+        fixture.MakeACommit("B");
+        fixture.BranchTo("hotfix/just-a-hotfix");
+        fixture.MakeACommit("C +semver: major");
+        fixture.MergeTo("main", removeBranchAfterMerging: true);
+        fixture.Checkout("develop");
+        fixture.MakeACommit("D");
+        fixture.Checkout("main");
+        fixture.MakeACommit("E");
+        fixture.ApplyTag("1.0.1");
+        fixture.Checkout("develop");
+        fixture.MergeNoFF("main");
+
+        // ✅ succeeds as expected
+        fixture.AssertFullSemver("1.1.0-alpha.7");
+    }
+
+    [TestCase(false, "2.0.0-alpha.3")]
+    [TestCase(true, "2.0.0-alpha.2")]
+    public void EnsureVersionAfterMainIsMergedBackToDevelopIsCorrectForTrunkBased(bool applyTag, string semanticVersion)
+    {
+        var configuration = GitFlowConfigurationBuilder.New
+            .WithVersionStrategy(VersionStrategies.TrunkBased)
+            .Build();
+
+        using EmptyRepositoryFixture fixture = new("main");
+
+        fixture.MakeACommit("A");
+        fixture.ApplyTag("1.0.0");
+        fixture.BranchTo("develop");
+        fixture.MakeACommit("B +semver: major");
+
+        // ✅ succeeds as expected
+        fixture.AssertFullSemver("2.0.0-alpha.1", configuration);
+
+        fixture.Checkout("main");
+        fixture.MakeACommit("C");
+        if (applyTag) fixture.ApplyTag("1.0.1");
+        fixture.Checkout("develop");
+        fixture.MergeNoFF("main");
+
+        // ✅ succeeds as expected
+        fixture.AssertFullSemver(semanticVersion, configuration);
+    }
+
+    [TestCase(false, "2.0.0-alpha.3")]
+    [TestCase(true, "2.0.0-alpha.3")]
+    public void EnsureVersionAfterMainIsMergedBackToDevelopIsCorrectForGitFlow(bool applyTag, string semanticVersion)
+    {
+        var configuration = GitFlowConfigurationBuilder.New.Build();
+
+        using EmptyRepositoryFixture fixture = new("main");
+
+        fixture.MakeACommit("A");
+        fixture.ApplyTag("1.0.0");
+        fixture.BranchTo("develop");
+        fixture.MakeACommit("B +semver: major");
+
+        // ✅ succeeds as expected
+        fixture.AssertFullSemver("2.0.0-alpha.1", configuration);
+
+        fixture.Checkout("main");
+        fixture.MakeACommit("C");
+        if (applyTag) fixture.ApplyTag("1.0.1");
+        fixture.Checkout("develop");
+        fixture.MergeNoFF("main");
+
+        // ✅ succeeds as expected
+        fixture.AssertFullSemver(semanticVersion, configuration);
+    }
 }

src/GitVersion.Core/VersionCalculation/IncrementStrategyFinder.cs

@@ -75,26 +75,21 @@ public VersionField DetermineIncrementedField(
     }
 
     private VersionField? FindCommitMessageIncrement(
-        EffectiveConfiguration configuration, ICommit? baseCommit, ICommit? currentCommit, string? label)
+        EffectiveConfiguration configuration, ICommit? baseVersionSource, ICommit currentCommit, string? label)
     {
         if (configuration.CommitMessageIncrementing == CommitMessageIncrementMode.Disabled)
         {
             return null;
         }
 
-        //get tags with valid version - depends on configuration (see #3757)
-        var targetShas = new Lazy<IReadOnlySet<string>>(() =>
-            this.taggedSemanticVersionRepository.GetTaggedSemanticVersions(configuration.TagPrefix, configuration.SemanticVersionFormat)
-            .SelectMany(_ => _).Where(_ => _.Value.IsMatchForBranchSpecificLabel(label)).Select(_ => _.Tag.TargetSha).ToHashSet()
+        IEnumerable<ICommit> commits = GetCommitHistory(
+            tagPrefix: configuration.TagPrefix,
+            semanticVersionFormat: configuration.SemanticVersionFormat,
+            baseVersionSource: baseVersionSource,
+            currentCommit: currentCommit,
+            label: label
         );
 
-        var commits = GetIntermediateCommits(baseCommit, currentCommit);
-        // consider commit messages since latest tag only (see #3071)
-        commits = commits
-            .Reverse()
-            .TakeWhile(x => !targetShas.Value.Contains(x.Sha))
-            .Reverse();
-
         if (configuration.CommitMessageIncrementing == CommitMessageIncrementMode.MergeMessageOnly)
         {
             commits = commits.Where(c => c.Parents.Count() > 1);
@@ -114,6 +109,41 @@ private static Regex TryGetRegexOrDefault(string? messageRegex, Regex defaultReg
             ? defaultRegex
             : CompiledRegexCache.GetOrAdd(messageRegex, pattern => new(pattern, RegexOptions.Compiled | RegexOptions.IgnoreCase));
 
+    private IReadOnlyCollection<ICommit> GetCommitHistory(
+        string? tagPrefix, SemanticVersionFormat semanticVersionFormat, ICommit? baseVersionSource, ICommit currentCommit, string? label)
+    {
+        var targetShas = new Lazy<HashSet<string>>(() =>
+            this.taggedSemanticVersionRepository.GetTaggedSemanticVersions(tagPrefix, semanticVersionFormat)
+                .SelectMany(_ => _).Where(_ => _.Value.IsMatchForBranchSpecificLabel(label)).Select(_ => _.Tag.TargetSha).ToHashSet()
+        );
+
+        var intermediateCommits = GetIntermediateCommits(baseVersionSource, currentCommit).ToArray();
+
+        var commitLog = intermediateCommits.ToDictionary(element => element.Id.Sha);
+
+        foreach (var intermediateCommit in intermediateCommits.Reverse())
+        {
+            if (targetShas.Value.Contains(intermediateCommit.Sha) && commitLog.Remove(intermediateCommit.Sha))
+            {
+                var parentCommits = intermediateCommit.Parents.ToList();
+                while (parentCommits.Count != 0)
+                {
+                    List<ICommit> temporaryList = new();
+                    foreach (var parentCommit in parentCommits)
+                    {
+                        if (commitLog.Remove(parentCommit.Sha))
+                        {
+                            temporaryList.AddRange(parentCommit.Parents);
+                        }
+                    }
+                    parentCommits = temporaryList;
+                }
+            }
+        }
+
+        return commitLog.Values;
+    }
+
     /// <summary>
     /// Get the sequence of commits in a repository between a <paramref name="baseCommit"/> (exclusive)
     /// and a particular <paramref name="headCommit"/> (inclusive)
@@ -149,7 +179,7 @@ private Dictionary<string, int> GetHeadCommitsMap(ICommit? headCommit) =>
     /// </summary>
     private ICommit[] GetHeadCommits(ICommit? headCommit) =>
         this.headCommitsCache.GetOrAdd(headCommit?.Sha ?? "NULL", () =>
-            GetCommitsReacheableFromHead(repository, headCommit).ToArray());
+            GetCommitsReacheableFromHead(headCommit).ToArray());
 
     private VersionField? GetIncrementFromCommit(ICommit commit, Regex majorRegex, Regex minorRegex, Regex patchRegex, Regex none) =>
         this.commitIncrementCache.GetOrAdd(commit.Sha, () =>
@@ -164,19 +194,15 @@ private ICommit[] GetHeadCommits(ICommit? headCommit) =>
         return null;
     }
 
-    /// <summary>
-    /// Query a <paramref name="repo"/> for the sequence of commits from the beginning to a particular
-    /// <paramref name="headCommit"/> (inclusive)
-    /// </summary>
-    private static IEnumerable<ICommit> GetCommitsReacheableFromHead(IGitRepository repo, ICommit? headCommit)
+    private IEnumerable<ICommit> GetCommitsReacheableFromHead(ICommit? headCommit)
     {
         var filter = new CommitFilter
         {
             IncludeReachableFrom = headCommit,
             SortBy = CommitSortStrategies.Topological | CommitSortStrategies.Reverse
         };
 
-        return repo.Commits.QueryBy(filter);
+        return repository.Commits.QueryBy(filter);
     }
 
     public IEnumerable<ICommit> GetMergedCommits(ICommit mergeCommit, int index)
@@ -202,7 +228,7 @@ private static ICommit GetMergedHead(ICommit mergeCommit)
     {
         var parents = mergeCommit.Parents.Skip(1).ToList();
         if (parents.Count > 1)
-            throw new NotSupportedException("Mainline development does not support more than one merge source in a single commit yet");
+            throw new NotSupportedException("GitVersion does not support more than one merge source in a single commit yet");
         return parents.Single();
     }