Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|From 2874b35e41a85731df8c7583f76c71eb249d3dfd Mon Sep 17 00:00:00 2001
|From: Felix Van der Jeugt <felix.vanderjeugt@gmail.com>
|Date: Wed, 19 Oct 2016 22:18:21 +0200
|Subject: [PATCH] tabcomplete with longest common prefix
|
|when hitting tab, the current input will be set to the longest common prefix
|of the current selection instead of the first item of the selection
|---
| dmenu.c | 32 ++++++++++++++------------------
| 1 file changed, 14 insertions(+), 18 deletions(-)
|
|diff --git a/dmenu.c b/dmenu.c
|index f803149..4bb1c23 100644
|--- a/dmenu.c
|+++ b/dmenu.c
--------------------------
Patching file dmenu.c using Plan A...
Hunk #1 succeeded at 219.
Hunk #2 succeeded at 228.
Hunk #3 succeeded at 241.
Hunk #4 succeeded at 250.
Hunk #5 succeeded at 299.
Hunk #6 succeeded at 478.
Hmm...  Ignoring the trailing garbage.
done