/// <summary>
/// Find the merge base of the two branches, i.e. the best common ancestor of the two branches' tips.
/// </summary>
public ICommit FindMergeBase(IBranch branch, IBranch otherBranch)
{
var key = Tuple.Create(branch, otherBranch);
if (mergeBaseCache.ContainsKey(key))
{
log.Debug($"Cache hit for merge base between '{branch.FriendlyName}' and '{otherBranch.FriendlyName}'.");
return(mergeBaseCache[key].MergeBase);
}
using (log.IndentLog($"Finding merge base between '{branch.FriendlyName}' and '{otherBranch.FriendlyName}'."))
{
// Otherbranch tip is a forward merge
var commitToFindCommonBase = otherBranch.Tip;
var commit = branch.Tip;
if (otherBranch.Tip.Parents.Contains(commit))
{
commitToFindCommonBase = otherBranch.Tip.Parents.First();
}
var findMergeBase = repository.FindMergeBase(commit, commitToFindCommonBase);
if (findMergeBase != null)
{
log.Info($"Found merge base of {findMergeBase.Sha}");
// We do not want to include merge base commits which got forward merged into the other branch
ICommit forwardMerge;
do
{
// Now make sure that the merge base is not a forward merge
forwardMerge = repository.GetForwardMerge(commitToFindCommonBase, findMergeBase);
if (forwardMerge != null)
{
// TODO Fix the logging up in this section
var second = forwardMerge.Parents.First();
log.Debug("Second " + second.Sha);
var mergeBase = repository.FindMergeBase(commit, second);
if (mergeBase == null)
{
log.Warning("Could not find mergbase for " + commit);
}
else
{
log.Debug("New Merge base " + mergeBase.Sha);
}
if (Equals(mergeBase, findMergeBase))
{
log.Debug("Breaking");
break;
}
findMergeBase = mergeBase;
commitToFindCommonBase = second;
log.Info($"Merge base was due to a forward merge, next merge base is {findMergeBase}");
}
} while (forwardMerge != null);
}
// Store in cache.
mergeBaseCache.Add(key, new MergeBaseData(findMergeBase));
log.Info($"Merge base of {branch.FriendlyName}' and '{otherBranch.FriendlyName} is {findMergeBase}");
return(findMergeBase);
}
}