Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|diff -up ../st-0.8.3/config.def.h ./config.def.h
|--- ../st-0.8.3/config.def.h	2020-04-27 13:58:27.000000000 +0200
|+++ ./config.def.h	2020-05-24 18:27:19.179361165 +0200
--------------------------
Patching file config.def.h using Plan A...
Hunk #1 succeeded at 4.
Hmm...  The next patch looks like a unified diff to me...
The text leading up to this was:
--------------------------
|diff -up ../st-0.8.3/st.h ./st.h
|--- ../st-0.8.3/st.h	2020-04-27 13:58:27.000000000 +0200
|+++ ./st.h	2020-05-24 18:27:20.255369735 +0200
--------------------------
Patching file st.h using Plan A...
Hunk #1 succeeded at 52.
Hmm...  The next patch looks like a unified diff to me...
The text leading up to this was:
--------------------------
|diff -up ../st-0.8.3/x.c ./x.c
|--- ../st-0.8.3/x.c	2020-04-27 13:58:27.000000000 +0200
|+++ ./x.c	2020-05-24 18:27:17.551348200 +0200
--------------------------
Patching file x.c using Plan A...
Hunk #1 succeeded at 1001.
done