Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|diff -up dwm-a/dwm.c dwm-b/dwm.c
|--- dwm-a/dwm.c	2019-02-02 06:55:28.000000000 -0600
|+++ dwm-b/dwm.c	2019-02-23 21:43:13.359179100 -0600
--------------------------
Patching file dwm.c using Plan A...
Hunk #1 succeeded at 719.
done