Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|From e8f792e8a482e461f9512ac8057d630284a47014 Mon Sep 17 00:00:00 2001
|From: Christopher Lang <christopher.lang.256@gmail.com>
|Date: Wed, 2 Aug 2023 16:02:15 +0100
|Subject: [dwm][patch] Stop input focus on pointers unselected monitor
|
|When the pointer is on an unselected monitor and is not moving, it
|should not interfere what window is selected/focused.
|
|1:
|
|From  https://tronche.com/gui/x/xlib/events/input-focus/normal-and-grabbed.html:
|When the focus moves from window A to window B, A is an inferior of B,
|and the pointer is in window P, the X server does the following:
|It generates a FocusOut event on window A...
|It generates a FocusOut event on each win...
|It generates a FocusIn event on window B,...
|If window P is an inferior of window B but window P is not window A or
|an inferior or ancestor of window A, it generates a FocusIn event on
|each window below window B, down to and including window P, with the
|detail member of each XFocusInEvent structure set to NotifyPointer.
|
|If focusmon selects a monitor with no clients then XSetInputFocus is
|called on the root window. Due to the above rules, an FocusIn event is sent
|to the window under the pointer which may be on another monitor. Now a
|window on one monitor is getting our keyboard input but another monitor
|is selected. In this undesirable state, a killclient shortcut (for
|example) will not destroy the window that is accepting input.
|
|We fix this by focusing on the bar window instead of root when an empty
|monitor is selected. Windows on other monitors are not a children of the
|bar window so they will not be focused by a NotifyPointer event.
|
|2:
|
|If a window is moved from the selected monitor to the monitor under the
|pointer and the rearrangement of windows on the second monitor causes a
|different window to be under the pointer, then an enternotify event is
|sent for that window. This causes that window to be focused and the
|second monitor to be selected. If the arrangement on the second monitor
|did not cause the pointer to be under a different window then the
|selected monitor would not change (very unpredictable behaviour!).
|
|We fix this by suppressing all enternotify events at the end of an
|arrange(NULL) call.
|---
| dwm.c | 11 ++++++++---
| 1 file changed, 8 insertions(+), 3 deletions(-)
|
|diff --git a/dwm.c b/dwm.c
|index f1d86b2..5b71b33 100644
|--- a/dwm.c
|+++ b/dwm.c
--------------------------
Patching file dwm.c using Plan A...
Hunk #1 succeeded at 383 (offset 1 line).
Hunk #2 succeeded at 391 (offset 1 line).
Hunk #3 succeeded at 810 (offset 1 line).
Hmm...  Ignoring the trailing garbage.
done