Test for issue 2786

Author: koershov

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

@@ -156,6 +156,128 @@ public void SupportBranches()
             fixture.AssertFullSemver("1.0.5-PullRequest0007.3", config);
         }
 
+        [Test]
+        public void HotfixBranchesWithTaggedCommitsOnMain()
+        {
+            using var fixture = new EmptyRepositoryFixture();
+            var configBumpMinor = new Config()
+            {
+                VersioningMode = VersioningMode.Mainline,
+                Increment = IncrementStrategy.Minor,
+                Branches =
+                {
+                    {
+                        Config.MainBranchKey,
+                        new BranchConfig
+                        {
+                            Regex = Config.MainBranchRegex,
+                            SourceBranches = new HashSet<string>
+                            {
+                                Config.DevelopBranchKey,
+                                Config.ReleaseBranchKey
+                            },
+                            Tag = string.Empty,
+                            PreventIncrementOfMergedBranchVersion = true,
+                            Increment = IncrementStrategy.Minor,
+                            IsMainline = true,
+                            PreReleaseWeight = 55000,
+                        }
+                    },
+                    {
+                        Config.HotfixBranchKey,
+                        new BranchConfig
+                        {
+                            Tag = ""
+                        }
+                    }
+                }
+            };
+
+            fixture.Repository.MakeACommit("1");
+            fixture.MakeATaggedCommit("1.0.0");
+
+            fixture.MakeACommit(); // 1.1.0
+            fixture.AssertFullSemver("1.1.0", configBumpMinor);
+            fixture.ApplyTag("1.1.0");
+            fixture.AssertFullSemver("1.1.0", configBumpMinor);
+
+            fixture.BranchTo("hotfix/may");
+            fixture.AssertFullSemver("1.1.1", configBumpMinor);
+
+            // Move main on
+            fixture.Checkout(MainBranch);
+            fixture.MakeACommit();
+            fixture.AssertFullSemver("1.2.0", configBumpMinor);
+
+            // Continue on hotfix
+            fixture.Checkout("hotfix/may");
+            fixture.MakeACommit(); // 1.2.1
+            fixture.AssertFullSemver("1.1.1", configBumpMinor);
+        }
+
+        [Test]
+        public void HotfixBranchesWithTaggedCommitsOnHotfix()
+        {
+            using var fixture = new EmptyRepositoryFixture();
+            var configBumpMinor = new Config()
+            {
+                VersioningMode = VersioningMode.Mainline,
+                Increment = IncrementStrategy.Minor,
+                Branches =
+                {
+                    {
+                        Config.MainBranchKey,
+                        new BranchConfig
+                        {
+                            Regex = Config.MainBranchRegex,
+                            SourceBranches = new HashSet<string>
+                            {
+                                Config.DevelopBranchKey,
+                                Config.ReleaseBranchKey
+                            },
+                            Tag = string.Empty,
+                            PreventIncrementOfMergedBranchVersion = true,
+                            Increment = IncrementStrategy.Minor,
+                            IsMainline = true,
+                            PreReleaseWeight = 55000,
+                        }
+                    },
+                    {
+                        Config.HotfixBranchKey,
+                        new BranchConfig
+                        {
+                            Tag = ""
+                        }
+                    }
+                }
+            };
+
+            fixture.Repository.MakeACommit("1");
+            fixture.MakeATaggedCommit("1.0.0");
+
+            fixture.MakeACommit(); // 1.1.0
+            fixture.AssertFullSemver("1.1.0", configBumpMinor);
+            fixture.ApplyTag("1.1.0");
+            fixture.AssertFullSemver("1.1.0", configBumpMinor);
+            fixture.MakeACommit(); // 1.2.0
+            fixture.AssertFullSemver("1.2.0", configBumpMinor);
+
+            fixture.BranchTo("hotfix/may");
+            fixture.AssertFullSemver("1.2.1", configBumpMinor);
+
+            // Move main on
+            fixture.Checkout(MainBranch);
+            fixture.MakeACommit();
+            fixture.AssertFullSemver("1.3.0", configBumpMinor);
+
+            // Continue on hotfix
+            fixture.Checkout("hotfix/may");
+            fixture.MakeACommit(); // 1.2.1
+            fixture.MakeATaggedCommit("1.2.2");
+            fixture.MakeACommit(); // 1.2.3
+            fixture.AssertFullSemver("1.2.3", configBumpMinor);
+        }
+
         [Test]
         public void VerifyForwardMerge()
         {

src/GitVersion.Core/VersionCalculation/MainlineVersionCalculator.cs

@@ -200,6 +200,7 @@ private ICommit GetEffectiveMainlineTip(IEnumerable<ICommit> mainlineCommitLog,
         private ICommit FindMergeBaseBeforeForwardMerge(ICommit baseVersionSource, IBranch mainline, out ICommit mainlineTip)
         {
             var mergeBase = repositoryStore.FindMergeBase(context.CurrentCommit, mainline.Tip);
+            //var mainlineCommitLog = repositoryStore.GetMainlineCommitLog(mergeBase.Parents.FirstOrDefault(), mainline.Tip).ToList();
             var mainlineCommitLog = repositoryStore.GetMainlineCommitLog(baseVersionSource, mainline.Tip).ToList();
 
             // find the mainline commit effective for versioning the current branch