Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|--- dwm.c.orig	2013-03-23 15:13:21.709978427 +0100
|+++ dwm.c	2013-03-23 15:13:13.366645236 +0100
--------------------------
Patching file dwm.c using Plan A...
Hunk #1 succeeded at 842.
Hunk #2 succeeded at 858.
Hunk #3 succeeded at 1207.
Hunk #4 succeeded at 1724.
done