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/historical/tagall
|Shortcut to move all (floating) windows from one tag to another.
|
|diff -r ec4baab78314 tagall.c
|--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
|+++ b/tagall.c	Fri Apr 06 08:23:21 2012 +0200
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(Creating file tagall.c...)
Patching file tagall.c using Plan A...
Empty context always matches.
Hunk #1 succeeded at 1.
done