patch 8.0.0421: diff mode wrong when adding line at end of buffer commit https://github.com/vim/vim/commit/f58a8475e17bd566760fc7e2a17d35ddf4edacf2 Author: Bram Moolenaar <Bram@vim.org> Date: Sun Mar 5 18:03:04 2017 +0100 patch 8.0.0421: diff mode wrong when adding line at end of buffer Problem: Diff mode is displayed wrong when adding a line at the end of a buffer. Solution: Adjust marks in diff mode. (James McCoy, closes #1329)