Hmm...  Looks like a unified diff to me...
The text leading up to this was:
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|Author: Jan Christoph Ebersbach <jceb@e-jc.de>
|URL: http://dwm.suckless.org/patches/pertag
|This patch keeps layout, mwfact, barpos and nmaster per tag.
|
|diff -r ec4baab78314 dwm.c
|--- a/dwm.c	Mon Dec 19 15:38:30 2011 +0100
|+++ b/dwm.c	Fri Apr 06 08:23:29 2012 +0200
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Patching file dwm.c using Plan A...
Hunk #1 succeeded at 124.
Hunk #2 succeeded at 144.
Hunk #3 succeeded at 289.
Hunk #4 succeeded at 657.
Hunk #5 succeeded at 669.
Hunk #6 succeeded at 1058.
Hunk #7 succeeded at 1585.
Hunk #8 succeeded at 1609.
Hunk #9 succeeded at 1762.
Hunk #10 succeeded at 1796.
Hunk #11 succeeded at 2096.
done