public virtual void TestPrepareCommitNoEmptyCommits() { // LUCENE-4972: DTW used to create empty commits even if no changes were made Directory dir = NewDirectory(); DirectoryTaxonomyWriter taxoWriter = new DirectoryTaxonomyWriter(dir); taxoWriter.AddCategory(new FacetLabel("a")); taxoWriter.PrepareCommit(); taxoWriter.Commit(); long gen1 = SegmentInfos.GetLastCommitGeneration(dir); taxoWriter.PrepareCommit(); taxoWriter.Commit(); long gen2 = SegmentInfos.GetLastCommitGeneration(dir); Assert.AreEqual(gen1, gen2, "empty commit should not have changed the index"); taxoWriter.Dispose(); dir.Dispose(); }