Subject: bug#20276: 24.4; diff-mode doesn't handle unified diff file headers without tabs

From: Stefan Monnier <[email-masked]>
Date: Wed, 08 Apr 2015 16:50:06 -0400

> Some diff programs will not emit tab + timestamp (as GNU diff does),
> but just the file name.

Which diff programs do that?

> -          (if (looking-at "[-*][-*][-*] \\([^\t]+\\)\t.*\n[-+][-+][-+]
> \\([^\t]+\\)")
> +          (if (looking-at "[-*][-*][-*] \\([^\t\n]+\\).*\n[-+][-+][-+]
> \\([^\t\n]+\\)")

Adding \n in the char-ranges is fine (it's a good change in itself), but
removing the \t increases the risk of false positives, so I'm a bit
worried about that.

        Stefan