[LibGit2Sharp] Line ending diff handling

CanCopeWithEndOfFileNewlineChanges.cs

        [Fact]
        /*
         * $ git init .
         * $ echo -ne 'a' > file.txt
         * $ git add .
         * $ git commit -m "No line ending"
         * $ echo -ne '\n' >> file.txt
         * $ git add .
         * $ git diff --cached
         * diff --git a/file.txt b/file.txt
         * index 2e65efe..7898192 100644
         * --- a/file.txt
         * +++ b/file.txt
         * @@ -1 +1 @@
         * -a
         * \ No newline at end of file
         * +a
         */
        public void CanCopeWithEndOfFileNewlineChanges()
        {
            var scd = BuildSelfCleaningDirectory();

            using (var repo = Repository.Init(scd.RootedDirectoryPath))
            {
                var fullpath = Path.Combine(repo.Info.WorkingDirectory, "file.txt");
                File.WriteAllText(fullpath, "a");

                repo.Index.Stage("file.txt");
                repo.Commit("Add file without line ending", DummySignature, DummySignature);

                File.AppendAllText(fullpath, "\n");
                repo.Index.Stage("file.txt");

                TreeChanges changes = repo.Diff.Compare(repo.Head.Tip.Tree, DiffTarget.Index);
                Assert.Equal(1, changes.Modified.Count());
                Assert.Equal(1, changes.LinesAdded);
                Assert.Equal(1, changes.LinesDeleted);

                var expected = new StringBuilder()
                    .Append("diff --git a/file.txt b/file.txt\n")
                    .Append("index 2e65efe..7898192 100644\n")
                    .Append("--- a/file.txt\n")
                    .Append("+++ b/file.txt\n")
                    .Append("@@ -1 +1 @@\n")
                    .Append("-a\n")
                    .Append("\\ No newline at end of file\n")
                    .Append("+a\n");

                Assert.Equal(expected.ToString(), changes.Patch);
            }
        }