LUCENE-3126. SegmentMerger.createCompoundFile does not document that it should not receive files that are not included in the .cfs, such as .del and .s* (separate norms). Today, that method is called from code which ensures that, but we should:
- Add some documentation to clarify that.
- Add some asserts so that if a test (or other code, running w/ -ea) does that, we catch it.
Will post a patch soon