Use new struct BranchCommit to lose less information. Use ExcludingBranches extension method.

Author: DanielRose

src/GitVersionCore/BranchCommit.cs

@@ -0,0 +1,51 @@
+namespace GitVersion
+{
+    using LibGit2Sharp;
+
+    /// <summary>
+    /// A commit, together with the branch to which the commit belongs.
+    /// </summary>
+    public struct BranchCommit
+    {
+        public static readonly BranchCommit Empty = new BranchCommit();
+
+        public BranchCommit(Commit commit, Branch branch) : this()
+        {
+            Branch = branch;
+            Commit = commit;
+        }
+
+        public Branch Branch { get; private set; }
+        public Commit Commit { get; private set; }
+
+        public bool Equals(BranchCommit other)
+        {
+            return Equals(Branch, other.Branch) && Equals(Commit, other.Commit);
+        }
+
+        public override bool Equals(object obj)
+        {
+            if (ReferenceEquals(null, obj))
+                return false;
+            return obj is BranchCommit && Equals((BranchCommit)obj);
+        }
+
+        public override int GetHashCode()
+        {
+            unchecked
+            {
+                return ((Branch != null ? Branch.GetHashCode() : 0) * 397) ^ (Commit != null ? Commit.GetHashCode() : 0);
+            }
+        }
+
+        public static bool operator ==(BranchCommit left, BranchCommit right)
+        {
+            return left.Equals(right);
+        }
+
+        public static bool operator !=(BranchCommit left, BranchCommit right)
+        {
+            return !left.Equals(right);
+        }
+    }
+}

src/GitVersionCore/BranchConfigurationCalculator.cs

@@ -87,7 +87,7 @@ static BranchConfig InheritBranchConfiguration(bool onlyEvaluateTrackedBranches,
 
                 var branchPoint = currentBranch.FindCommitBranchWasBranchedFrom(repository, excludedInheritBranches.ToArray());
                 List<Branch> possibleParents;
-                if (branchPoint == null)
+                if (branchPoint == BranchCommit.Empty)
                 {
                     possibleParents = currentCommit.GetBranchesContainingCommit(repository, branchesToEvaluate, true)
                         // It fails to inherit Increment branch configuration if more than 1 parent;
@@ -97,7 +97,7 @@ static BranchConfig InheritBranchConfiguration(bool onlyEvaluateTrackedBranches,
                 }
                 else
                 {
-                    var branches = branchPoint.GetBranchesContainingCommit(repository, branchesToEvaluate, true).ToList();
+                    var branches = branchPoint.Commit.GetBranchesContainingCommit(repository, branchesToEvaluate, true).ToList();
                     if (branches.Count > 1)
                     {
                         var currentTipBranches = currentCommit.GetBranchesContainingCommit(repository, branchesToEvaluate, true).ToList();

src/GitVersionCore/GitVersionCore.csproj

@@ -72,6 +72,7 @@
     <Compile Include="AssemblyVersioningScheme.cs" />
     <Compile Include="AssemblyVersionsGenerator.cs" />
     <Compile Include="Authentication.cs" />
+    <Compile Include="BranchCommit.cs" />
     <Compile Include="BranchConfigurationCalculator.cs" />
     <Compile Include="BuildServers\AppVeyor.cs" />
     <Compile Include="BuildServers\BuildServerBase.cs" />

src/GitVersionCore/LibGitExtensions.cs

@@ -36,7 +36,7 @@ public static IEnumerable<SemanticVersion> GetVersionTagsOnBranch(this Branch br
         /// Find the commit where the given branch was branched from another branch.
         /// If there are multiple such commits and branches, returns the newest commit.
         /// </summary>
-        public static Commit FindCommitBranchWasBranchedFrom([NotNull] this Branch branch, IRepository repository, params Branch[] excludedBranches)
+        public static BranchCommit FindCommitBranchWasBranchedFrom([NotNull] this Branch branch, IRepository repository, params Branch[] excludedBranches)
         {
             const string missingTipFormat = "{0} has no tip. Please see http://example.com/docs for information on how to fix this.";
 
@@ -50,35 +50,25 @@ public static Commit FindCommitBranchWasBranchedFrom([NotNull] this Branch branc
                 if (branch.Tip == null)
                 {
                     Logger.WriteWarning(string.Format(missingTipFormat, branch.FriendlyName));
-                    return null;
+                    return BranchCommit.Empty;
                 }
 
                 var otherBranches = repository.Branches
-                    .Except(excludedBranches)
-                    .Where(b => IsSameBranch(branch, b))
-                    .ToList();
+                    .ExcludingBranches(excludedBranches)
+                    .Where(b => !IsSameBranch(branch, b));
                 var mergeBases = otherBranches.Select(otherBranch =>
                 {
                     if (otherBranch.Tip == null)
                     {
                         Logger.WriteWarning(string.Format(missingTipFormat, otherBranch.FriendlyName));
-                        return null;
+                        return BranchCommit.Empty;
                     }
 
                     var findMergeBase = FindMergeBase(branch, otherBranch, repository);
-                    return new
-                    {
-                        mergeBaseCommit = findMergeBase,
-                        branch = otherBranch
-                    };
-                }).Where(b => b.mergeBaseCommit != null).OrderByDescending(b => b.mergeBaseCommit.Committer.When).ToList();
+                    return new BranchCommit(findMergeBase,otherBranch);
+                }).Where(b => b.Commit != null).OrderByDescending(b => b.Commit.Committer.When);
 
-                var firstOrDefault = mergeBases.FirstOrDefault();
-                if (firstOrDefault != null)
-                {
-                    return firstOrDefault.mergeBaseCommit;
-                }
-                return null;
+                return mergeBases.FirstOrDefault();
             }
         }
 
@@ -127,11 +117,28 @@ public static Commit FindMergeBase(this Branch branch, Branch otherBranch, IRepo
             }
         }
 
-        static bool IsSameBranch(Branch branch, Branch b)
+        /// <summary>
+        /// Checks if the two branch objects refer to the same branch (have the same friendly name).
+        /// </summary>
+        public static bool IsSameBranch(Branch branch, Branch otherBranch)
+        {
+            // For each branch, fixup the friendly name if the branch is remote.
+            var otherBranchFriendlyName = otherBranch.IsRemote ?
+                otherBranch.FriendlyName.Substring(otherBranch.FriendlyName.IndexOf("/", StringComparison.Ordinal) + 1) :
+                otherBranch.FriendlyName;
+            var branchFriendlyName = branch.IsRemote ?
+                branch.FriendlyName.Substring(branch.FriendlyName.IndexOf("/", StringComparison.Ordinal) + 1) :
+                branch.FriendlyName;
+
+            return otherBranchFriendlyName == branchFriendlyName;
+        }
+
+        /// <summary>
+        /// Exclude the given branches (by value equality according to friendly name).
+        /// </summary>
+        public static IEnumerable<Branch> ExcludingBranches([NotNull] this IEnumerable<Branch> branches, [NotNull] IEnumerable<Branch> branchesToExclude)
         {
-            return (b.IsRemote ? 
-                b.FriendlyName.Substring(b.FriendlyName.IndexOf("/", StringComparison.Ordinal) + 1) : 
-                b.FriendlyName) != branch.FriendlyName;
+            return branches.Where(b => branchesToExclude.All(bte => !IsSameBranch(b, bte)));
         }
 
         public static IEnumerable<Branch> GetBranchesContainingCommit([NotNull] this Commit commit, IRepository repository, IList<Branch> branches, bool onlyTrackedBranches)

src/GitVersionCore/VersionCalculation/BaseVersionCalculators/VersionInBranchBaseVersionStrategy.cs

@@ -27,7 +27,7 @@ public IEnumerable<BaseVersion> GetVersions(GitVersionContext context, string ta
             {
                 var commitBranchWasBranchedFrom = currentBranch.FindCommitBranchWasBranchedFrom(repository);
                 var branchNameOverride = branchName.RegexReplace("[-/]" + versionInBranch.Item1, string.Empty);
-                yield return new BaseVersion(context, "Version in branch name", false, versionInBranch.Item2, commitBranchWasBranchedFrom, branchNameOverride);
+                yield return new BaseVersion(context, "Version in branch name", false, versionInBranch.Item2, commitBranchWasBranchedFrom.Commit, branchNameOverride);
             }
         }