Fixed some exceptions which were causing tests to blow up and not get a result

Author: JakeGinnivan

GitVersionCore/GitVersionContext.cs

@@ -107,8 +107,7 @@ KeyValuePair<string, BranchConfig> GetBranchConfiguration(Branch currentBranch)
 
                 if (branchConfiguration.Increment == IncrementStrategy.Inherit)
                 {
-                    var tips = Repository.Branches.Select(b => b.Tip).Where(c => c.Sha != CurrentCommit.Sha).ToList();
-                    var branchPoint = Repository.Commits.First(c => tips.Contains(c) || c.Parents.Count() > 1);
+                    var branchPoint = currentBranch.FindCommitBranchWasBranchedFrom(Repository);
                     var branches = ListBranchesContaininingCommit(Repository, branchPoint.Sha).ToArray();
                     var currentTipBranches = ListBranchesContaininingCommit(Repository, CurrentCommit.Sha).ToArray();
                     var branchNameComparer = new BranchNameComparer();

GitVersionCore/GitVersionCore.csproj

@@ -96,6 +96,7 @@
     <Compile Include="VersionCalculation\BaseVersionCalculators\MergeMessageBaseVersionStrategy.cs" />
     <Compile Include="VersionCalculation\BaseVersionCalculators\VersionInBranchBaseVersionStrategy.cs" />
     <Compile Include="VersionCalculation\BaseVersionStrategy.cs" />
+    <Compile Include="VersionCalculation\FallbackBaseVersionStrategy.cs" />
     <Compile Include="VersionCalculation\IBaseVersionCalculator.cs" />
     <Compile Include="VersionCalculation\IMetaDataCalculator.cs" />
     <Compile Include="VersionCalculation\MetaDataCalculator.cs" />

GitVersionCore/LibGitExtensions.cs

@@ -24,6 +24,12 @@ public static Branch FindBranch(this IRepository repository, string branchName)
             return repository.Branches.FirstOrDefault(x => x.Name == "origin/" + branchName);
         }
 
+        public static Commit FindCommitBranchWasBranchedFrom(this Branch branch, IRepository repository)
+        {
+            var tips = repository.Branches.Select(b => b.Tip).Where(c => c.Sha != branch.Tip.Sha).ToList();
+            return repository.Commits.FirstOrDefault(c => tips.Contains(c) || c.Parents.Count() > 1) ?? branch.Tip;
+        }
+
         public static IEnumerable<Tag> TagsByDate(this IRepository repository, Commit commit)
         {
             return repository.Tags

GitVersionCore/VersionCalculation/BaseVersionCalculators/VersionInBranchBaseVersionStrategy.cs

@@ -10,8 +10,9 @@ public override BaseVersion GetVersion(GitVersionContext context)
             var versionInBranch = GetVersionInBranch(context);
             if (versionInBranch != null)
             {
-                var firstCommitOfBranch = context.CurrentBranch.Commits.Last();
-                return new BaseVersion(false, true, versionInBranch.Item2, firstCommitOfBranch);
+                var commitBranchWasBranchedFrom = context.CurrentBranch.FindCommitBranchWasBranchedFrom(context.Repository);
+                var baseVersionSource = context.CurrentBranch.Commits.First(c => c.Sha != commitBranchWasBranchedFrom.Sha);
+                return new BaseVersion(false, true, versionInBranch.Item2, baseVersionSource);
             }
 
             return null;

GitVersionCore/VersionCalculation/FallbackBaseVersionStrategy.cs

@@ -0,0 +1,13 @@
+namespace GitVersion.VersionCalculation
+{
+    using System.Linq;
+    using GitVersion.VersionCalculation.BaseVersionCalculators;
+
+    public class FallbackBaseVersionStrategy : BaseVersionStrategy
+    {
+        public override BaseVersion GetVersion(GitVersionContext context)
+        {
+            return new BaseVersion(false, true, new SemanticVersion(minor: 1), context.CurrentBranch.Commits.Last());
+        }
+    }
+}

GitVersionCore/VersionCalculation/NewNextVersionCalculator.cs

@@ -14,6 +14,7 @@ public NewNextVersionCalculator(IBaseVersionCalculator baseVersionCalculator = n
             this.metaDataCalculator = metaDataCalculator ?? new MetaDataCalculator();
             baseVersionFinder = baseVersionCalculator ??
                 new BaseVersionCalculator(
+                    new FallbackBaseVersionStrategy(),
                 new ConfigNextVersionBaseVersionStrategy(),
                 new LastTagBaseVersionStrategy(),
                 new MergeMessageBaseVersionStrategy(),