Make sure that we're not evaluating excluded branches.

This commit removes the excluded branches before we're trying to find
branches containing the commit.

This will also exclude branches we it's not possible to find a
configuration.

Fixes #684

Author: orjan

src/GitVersionCore/BranchConfigurationCalculator.cs

@@ -51,29 +51,33 @@ static KeyValuePair<string, BranchConfig> InheritBranchConfiguration(bool onlyEv
                 {
                     excludedBranches = CalculateWhenMultipleParents(repository, currentCommit, ref currentBranch, excludedBranches);
                 }
+
                 if (excludedInheritBranches == null)
                 {
                     excludedInheritBranches = repository.Branches.Where(b =>
                     {
                         var branchConfig = LookupBranchConfiguration(config, b);
-                        return branchConfig.Length == 1 && branchConfig[0].Value.Increment == IncrementStrategy.Inherit;
+
+                        // NOTE: if length is 0 we couldn't find the configuration for the branch e.g. "origin/master"
+                        // NOTE: if the length is greater than 1 we cannot decide which merge strategy to pick
+                        return (branchConfig.Length != 1) || (branchConfig.Length == 1 && branchConfig[0].Value.Increment == IncrementStrategy.Inherit);
                     }).ToList();
                 }
                 excludedBranches.ToList().ForEach(excludedInheritBranches.Add);
+                var branchesToEvaluate = repository.Branches.Except(excludedInheritBranches).ToList();
 
                 var branchPoint = currentBranch.FindCommitBranchWasBranchedFrom(repository, excludedInheritBranches.ToArray());
-
                 List<Branch> possibleParents;
                 if (branchPoint == null)
                 {
-                    possibleParents = currentCommit.GetBranchesContainingCommit(repository, true).Except(excludedInheritBranches).ToList();
+                    possibleParents = currentCommit.GetBranchesContainingCommit(repository, branchesToEvaluate, true).ToList();
                 }
                 else
                 {
-                    var branches = branchPoint.GetBranchesContainingCommit(repository, true).Except(excludedInheritBranches).ToList();
+                    var branches = branchPoint.GetBranchesContainingCommit(repository, branchesToEvaluate, true).ToList();
                     if (branches.Count > 1)
                     {
-                        var currentTipBranches = currentCommit.GetBranchesContainingCommit(repository, true).Except(excludedInheritBranches).ToList();
+                        var currentTipBranches = currentCommit.GetBranchesContainingCommit(repository, branchesToEvaluate, true).ToList();
                         possibleParents = branches.Except(currentTipBranches).ToList();
                     }
                     else

src/GitVersionCore/GitVersionContext.cs

@@ -48,7 +48,7 @@ public GitVersionContext(IRepository repository, Branch currentBranch, Config co
 
             if (currentBranch.IsDetachedHead())
             {
-                CurrentBranch = CurrentCommit.GetBranchesContainingCommit(repository, OnlyEvaluateTrackedBranches).OnlyOrDefault() ?? currentBranch;
+                CurrentBranch = CurrentCommit.GetBranchesContainingCommit(repository, repository.Branches.ToList(), OnlyEvaluateTrackedBranches).OnlyOrDefault() ?? currentBranch;
             }
             else
             {

src/GitVersionCore/LibGitExtensions.cs

@@ -68,10 +68,10 @@ static bool IsSameBranch(Branch branch, Branch b)
             return (b.IsRemote ? b.Name.Replace(b.Remote.Name + "/", string.Empty) : b.Name) != branch.Name;
         }
 
-        public static IEnumerable<Branch> GetBranchesContainingCommit(this Commit commit, IRepository repository, bool onlyTrackedBranches)
+        public static IEnumerable<Branch> GetBranchesContainingCommit(this Commit commit, IRepository repository, IList<Branch> branches, bool onlyTrackedBranches)
         {
             var directBranchHasBeenFound = false;
-            foreach (var branch in repository.Branches)
+            foreach (var branch in branches)
             {
                 if (branch.Tip.Sha != commit.Sha || (onlyTrackedBranches && !branch.IsTracking))
                 {
@@ -87,7 +87,7 @@ public static IEnumerable<Branch> GetBranchesContainingCommit(this Commit commit
                 yield break;
             }
 
-            foreach (var branch in repository.Branches.Where(b => (onlyTrackedBranches && !b.IsTracking)))
+            foreach (var branch in branches.Where(b => (onlyTrackedBranches && !b.IsTracking)))
             {
                 var commits = repository.Commits.QueryBy(new CommitFilter { Since = branch }).Where(c => c.Sha == commit.Sha);