Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|https://github.com/sunaku/.dwm/compare/tip...spawn_cwd
|---
|diff --git a/dwm.c b/dwm.c
|index 1d78655..156ee60 100644
|--- a/dwm.c
|+++ b/dwm.c
--------------------------
Patching file dwm.c using Plan A...
Hunk #1 succeeded at 20.
Hunk #2 succeeded at 29.
Hunk #3 succeeded at 1664.
done