Fixed all broken existing tests

Author: JakeGinnivan

GitVersionCore/BranchConfigurationCalculator.cs

@@ -83,10 +83,15 @@ static KeyValuePair<string, BranchConfig> InheritBranchConfiguration(bool onlyEv
             else
             {
                 var branches = branchPoint.GetBranchesContainingCommit(repository, true).Except(excludedInheritBranches).ToList();
-                var currentTipBranches = currentCommit.GetBranchesContainingCommit(repository, true).Except(excludedInheritBranches).ToList();
-                possibleParents = branches
-                    .Except(currentTipBranches)
-                    .ToList();
+                if (branches.Count > 1)
+                {
+                    var currentTipBranches = currentCommit.GetBranchesContainingCommit(repository, true).Except(excludedInheritBranches).ToList();
+                    possibleParents = branches.Except(currentTipBranches).ToList();
+                }
+                else
+                {
+                    possibleParents = branches;
+                }
             }
 
             Logger.WriteInfo("Found possible parent branches: " + string.Join(", ", possibleParents.Select(p => p.Name)));

GitVersionCore/LibGitExtensions.cs

@@ -26,7 +26,7 @@ public static Branch FindBranch(this IRepository repository, string branchName)
 
         public static Commit FindCommitBranchWasBranchedFrom(this Branch branch, IRepository repository, params Branch[] excludedBranches)
         {
-            var otherBranches = repository.Branches.Where(b => !b.IsRemote).Except(excludedBranches).Except(new [] { branch });
+            var otherBranches = repository.Branches.Where(b => !b.IsRemote).Except(excludedBranches).Except(new [] { branch }).ToList();
             var mergeBases = otherBranches.Select(b =>
             {
                 var otherCommit = b.Tip;