Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|Author: Jan Christoph Ebersbach <jceb@e-jc.de>
|URL: http://dwm.suckless.org/patches/swapfocus
|This patch makes it possible to switch focus with one single shortcut (alt-s)
|instead of having to think if you should use alt-j or alt-k for reaching the
|last used window.
|
|Index: dwm/dwm.c
|===================================================================
|--- dwm/dwm.c.orig
|+++ dwm/dwm.c
--------------------------
Patching file dwm.c using Plan A...
Hunk #1 succeeded at 207.
Hunk #2 succeeded at 237.
Hunk #3 succeeded at 1647.
Hunk #4 succeeded at 1756.
Hunk #5 succeeded at 2123.
done