Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|From 17acbdcb56d0d2f39507a3f67ef329c14a213ef6 Mon Sep 17 00:00:00 2001
|From: MLquest8 <miskuzius@gmail.com>
|Date: Thu, 18 Jun 2020 15:34:18 +0400
|Subject: [PATCH] attachtop. Attaches new client below the last master/on top
| of the stack. In case of nmaster = 1 behaves like attachaside.
|
|---
| dwm.c | 29 +++++++++++++++++++++++++----
| 1 file changed, 25 insertions(+), 4 deletions(-)
|
|diff --git a/dwm.c b/dwm.c
|index 9fd0286..7ced982 100644
|--- a/dwm.c
|+++ b/dwm.c
--------------------------
Patching file dwm.c using Plan A...
Hunk #1 succeeded at 49.
Hunk #2 succeeded at 148.
Hunk #3 succeeded at 408 (offset -1 lines).
Hunk #4 succeeded at 1083 (offset -1 lines).
Hunk #5 succeeded at 1438 (offset -1 lines).
Hunk #6 succeeded at 1919 (offset -2 lines).
Hmm...  Ignoring the trailing garbage.
done