I'm using a very recent build: e4896856172

Steps to reproduce bug:

- Open attached diff. Emacs should open it in diff-mode
- Put point on 'd' in the second "diff": (goto-char 98)
- M-k

This should kill the hunk we're on. We are unambiguously sitting on the
second hunk, but the latest diff-mode is confused, thinks we're on the
first hunk, and kills that instead. Kinda. Moving the point even one
character forward makes it work.