>So does that mean that PRs are mutable? Of course they are.
Note: 1) If you access PR via git interface, you have immediate visibility that PR is updated. There's no way to mutate the contents of a commit. Its Id would have to be updated. 2) In github.com UI, commits/comments are ordered by date, so it is obvious when commit was created afterwards. Just go ahead and check that my commit is below Philippe's comment: https://github.com/apache/jmeter/pull/176#issuecomment-204965711 Note: each commit is immutable, however one can update the PR with _another_ set of commits. That is useful for: 1) Corrections for code review 2) Merging multiple commits into a single one. For instance, Philippe's https://github.com/apache/jmeter/pull/179 consists of 7 commits, however I do not see much value in publishing 7 "work-in-progress" commits. Well, it might make sense if you publish one, then another (so other can see the diff), but in general single commit per feature makes more sense for me. Vladimir