CommitFilter: add simplify-by-first-parent option

Now that this is doable directly inside the revision walker, let's
expose it as a possible filter option.

This fixes #258.

1 files changed, 12 insertions, 0 deletions

diff --git a/LibGit2Sharp.Tests/CommitFixture.cs b/LibGit2Sharp.Tests/CommitFixture.cs
index fc5cc373..33a781eb 100644
--- a/LibGit2Sharp.Tests/CommitFixture.cs
+++ b/LibGit2Sharp.Tests/CommitFixture.cs
@@ -177,6 +177,18 @@ namespace LibGit2Sharp.Tests
         }
 
         [Fact]
+        public void CanSimplifyByFirstParent()
+        {
+            AssertEnumerationOfCommits(
+                repo => new CommitFilter { Since = repo.Head, FirstParent = true },
+            new[]
+            {
+                "4c062a6", "be3563a", "9fd738e",
+                "4a202b3", "5b5b025", "8496071",
+            });
+        }
+
+        [Fact]
         public void CanGetParentsCount()
         {
             using (var repo = new Repository(BareTestRepoPath))