From 9b983fecf999b9f50946973f2379a5ce00491cad Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Tue, 30 Jan 2024 10:44:58 +1000
Subject: [PATCH] dix: don't push the XKB state to a non-existing master
 keyboard

If our master keyboard is disabled, GetMaster() returns NULL and
we segfault in XkbPushLockedStateToSlaves().

Fixes 45fb3a934dc0db51584aba37c2f9d73deff9191d
Fixes #1611

Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1256>
---
 dix/devices.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/dix/devices.c b/dix/devices.c
index 48f701be3..b4b15a159 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -2699,11 +2699,14 @@ AttachDevice(ClientPtr client, DeviceIntPtr dev, DeviceIntPtr master)
         dev->spriteInfo->paired = dev;
     }
     else {
+        DeviceIntPtr keyboard = GetMaster(dev, MASTER_KEYBOARD);
+
         dev->spriteInfo->sprite = master->spriteInfo->sprite;
         dev->spriteInfo->paired = master;
         dev->spriteInfo->spriteOwner = FALSE;
 
-        XkbPushLockedStateToSlaves(GetMaster(dev, MASTER_KEYBOARD), 0, 0);
+        if (keyboard)
+            XkbPushLockedStateToSlaves(keyboard, 0, 0);
         RecalculateMasterButtons(master);
     }