[mutter/wip/carlosg/xwayland-crash-safe-again] wayland: Handle forced Xwayland shutdown elegantly

[Carlos Garnacho <carlosg src gnome org>]

commit e56fd33e501e093781169454bc0dba0f7830151b
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Jan 20 16:55:08 2021 +0100

    wayland: Handle forced Xwayland shutdown elegantly
    
    In the shutdown paths we check with the X11 display whether there's
    remaining clients. However this happens in paths that happen after
    the MetaX11Display vanished in the case of Xwayland crash.
    
    Since in that situation the clients are forcibly vanishing too,
    skip the client check.

 src/wayland/meta-xwayland.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/wayland/meta-xwayland.c b/src/wayland/meta-xwayland.c
index b11b32b3eb..53017c3571 100644
--- a/src/wayland/meta-xwayland.c
+++ b/src/wayland/meta-xwayland.c
@@ -535,7 +535,8 @@ shutdown_xwayland_cb (gpointer data)
                                                       META_EXPERIMENTAL_FEATURE_AUTOCLOSE_XWAYLAND))
     return G_SOURCE_REMOVE;
 
-  if (!can_terminate_xwayland (display->x11_display->xdisplay))
+  if (display->x11_display &&
+      !can_terminate_xwayland (display->x11_display->xdisplay))
     return G_SOURCE_CONTINUE;
 
   meta_verbose ("Shutting down Xwayland");