Merge pull request #1006 from JakeGinnivan/FixDuplicateKeyException

Fixing exception when forward merging support branches into master wi…

Author: JakeGinnivan

src/GitVersionCore.Tests/IntegrationTests/MainlineDevelopmentMode.cs

@@ -160,6 +160,36 @@ public void VerifyForwardMerge()
             fixture.AssertFullSemver(config, "1.0.4-foo.3");
         }
     }
+
+    [Test]
+    public void VerifySupportForwardMerge()
+    {
+        using (var fixture = new EmptyRepositoryFixture())
+        {
+            fixture.Repository.MakeACommit("1");
+            fixture.MakeATaggedCommit("1.0.0");
+            fixture.MakeACommit(); // 1.0.1
+
+            fixture.BranchTo("support/1.0", "support10");
+            fixture.MakeACommit();
+            fixture.MakeACommit();
+
+            fixture.Checkout("master");
+            fixture.MakeACommit("+semver: minor");
+            fixture.AssertFullSemver(config, "1.1.0");
+            fixture.MergeNoFF("support/1.0");
+            fixture.AssertFullSemver(config, "1.1.2");
+            fixture.MakeACommit();
+            fixture.AssertFullSemver(config, "1.1.3");
+            fixture.Checkout("support/1.0");
+            fixture.AssertFullSemver(config, "1.0.4");
+
+            fixture.BranchTo("feature/foo", "foo");
+            fixture.MakeACommit();
+            fixture.MakeACommit();
+            fixture.AssertFullSemver(config, "1.0.4-foo.2"); // TODO This probably should be 1.0.5
+        }
+    }
 }
 
 static class CommitExtensions

src/GitVersionCore/BranchConfigurationCalculator.cs

@@ -131,7 +131,11 @@ static KeyValuePair<string, BranchConfig> InheritBranchConfiguration(bool onlyEv
                 var chosenBranch = repository.Branches.FirstOrDefault(b => Regex.IsMatch(b.FriendlyName, "^develop", RegexOptions.IgnoreCase)
                                                                            || Regex.IsMatch(b.FriendlyName, "master$", RegexOptions.IgnoreCase));
                 if (chosenBranch == null)
+                {
+                    // TODO We should call the build server to generate this exception, each build server works differently
+                    // for fetch issues and we could give better warnings.
                     throw new InvalidOperationException("Could not find a 'develop' or 'master' branch, neither locally nor remotely.");
+                }
 
                 var branchName = chosenBranch.FriendlyName;
                 Logger.WriteWarning(errorMessage + Environment.NewLine + Environment.NewLine + "Falling back to " + branchName + " branch config");

src/GitVersionCore/VersionCalculation/NextVersionCalculator.cs

@@ -166,27 +166,44 @@ static Commit GetMainlineTip(GitVersionContext context)
         {
             var mainlineBranchConfigs = context.FullConfiguration.Branches.Where(b => b.Value.IsMainline == true).ToList();
             var seenMainlineTips = new List<string>();
-            var mainlineBranches = context.Repository.Branches.Where(b =>
-            {
-                return mainlineBranchConfigs.Any(c => Regex.IsMatch(b.FriendlyName, c.Key));
-            }).Where(b =>
-            {
-                if (seenMainlineTips.Contains(b.Tip.Sha))
+            var mainlineBranches = context.Repository.Branches
+                .Where(b =>
                 {
-                    Logger.WriteInfo("Multiple possible mainlines pointing at the same commit, dropping " + b.FriendlyName);
-                    return false;
-                }
-                seenMainlineTips.Add(b.Tip.Sha);
-                return true;
-            }).ToDictionary(b => context.Repository.ObjectDatabase.FindMergeBase(b.Tip, context.CurrentCommit).Sha, b => b);
-            Logger.WriteInfo("Found possible mainline branches: " + string.Join(", ", mainlineBranches.Values.Select(b => b.FriendlyName)));
+                    return mainlineBranchConfigs.Any(c => Regex.IsMatch(b.FriendlyName, c.Key));
+                })
+                .Where(b =>
+                {
+                    if (seenMainlineTips.Contains(b.Tip.Sha))
+                    {
+                        Logger.WriteInfo("Multiple possible mainlines pointing at the same commit, dropping " + b.FriendlyName);
+                        return false;
+                    }
+                    seenMainlineTips.Add(b.Tip.Sha);
+                    return true;
+                })
+               .GroupBy(b => context.Repository.ObjectDatabase.FindMergeBase(b.Tip, context.CurrentCommit).Sha)
+               .ToDictionary(b => b.Key, b => b.ToList());
+
+            var allMainlines = mainlineBranches.Values.SelectMany(branches => branches.Select(b => b.FriendlyName));
+            Logger.WriteInfo("Found possible mainline branches: " + string.Join(", ", allMainlines));
 
             // Find closest mainline branch
             var firstMatchingCommit = context.CurrentBranch.Commits.First(c => mainlineBranches.ContainsKey(c.Sha));
-            var mainlineBranch = mainlineBranches[firstMatchingCommit.Sha];
-            Logger.WriteInfo("Mainline for current branch is " + mainlineBranch.FriendlyName);
+            var possibleMainlineBranches = mainlineBranches[firstMatchingCommit.Sha];
+
+            if (possibleMainlineBranches.Count == 1)
+            {
+                var mainlineBranch = possibleMainlineBranches[0];
+                Logger.WriteInfo("Mainline for current branch is " + mainlineBranch.FriendlyName);
+                return mainlineBranch.Tip;
+            }
 
-            return mainlineBranch.Tip;
+            var chosenMainline = possibleMainlineBranches[0];
+            Logger.WriteInfo(string.Format(
+                "Multiple mainlines ({0}) have the same merge base for the current branch, choosing {1} because we found that branch first...",
+                string.Join(", ", possibleMainlineBranches.Select(b => b.FriendlyName)),
+                chosenMainline.FriendlyName));
+            return chosenMainline.Tip;
         }
 
         private static SemanticVersion IncrementForEachCommit(GitVersionContext context, List<Commit> directCommits, SemanticVersion mainlineVersion)