From d74a046060df81ea766e999b4110e926b121cf2e Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Mon, 18 Jun 2018 10:39:11 +0000
Subject: [PATCH] window/wayland: Always update monitor for non-user ops

meta_window_wayland_update_main_monitor() would skip the monitor update
if the difference in scale between the old and the new monitor would
cause another monitor change.

While this is suitable when the monitor change results from a user
interactively moving the surface between monitors of different scales,
this can leave dangling pointers to freed monitors when this is
triggered by a change of monitor configuration.

Make sure we update the monitor unconditionally if not from a user
operation.

Closes: https://gitlab.gnome.org/GNOME/mutter/issues/189


(cherry picked from commit a3da4b8d5bd217c0262fd9361036877d155a300f)
---
 src/wayland/meta-window-wayland.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/wayland/meta-window-wayland.c b/src/wayland/meta-window-wayland.c
index 705bc4981..8bafb252f 100644
--- a/src/wayland/meta-window-wayland.c
+++ b/src/wayland/meta-window-wayland.c
@@ -413,6 +413,12 @@ meta_window_wayland_update_main_monitor (MetaWindow *window,
       return;
     }
 
+  if (!user_op)
+    {
+      window->monitor = to;
+      return;
+    }
+
   from_scale = meta_logical_monitor_get_scale (from);
   to_scale = meta_logical_monitor_get_scale (to);
 
-- 
2.19.0