[mutter] xwayland: Handle shutting down without having started

[Marge Bot <marge-bot src gnome org>]

commit 4490d4524bda0f00c2fd688308c6061253170530
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu May 6 11:02:42 2021 +0200

    xwayland: Handle shutting down without having started
    
    We initialize, but might not start, e.g. when a test case just needs a
    backend and doesn't start mutter. When cleaning up, we'll still try to
    clean up Xwayland integration, and this commit handles cleaning up
    without having made the mess.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1856>

 src/wayland/meta-wayland.c  |  2 +-
 src/wayland/meta-xwayland.c | 11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)
---
diff --git a/src/wayland/meta-wayland.c b/src/wayland/meta-wayland.c
index 153d61954c..8f16aa429d 100644
--- a/src/wayland/meta-wayland.c
+++ b/src/wayland/meta-wayland.c
@@ -595,7 +595,7 @@ meta_wayland_finalize (void)
   if (compositor->wayland_display)
     wl_display_destroy_clients (compositor->wayland_display);
 
-  meta_wayland_seat_free (compositor->seat);
+  g_clear_pointer (&compositor->seat, meta_wayland_seat_free);
 
   g_clear_pointer (&compositor->display_name, g_free);
   g_clear_pointer (&compositor->wayland_display, wl_display_destroy);
diff --git a/src/wayland/meta-xwayland.c b/src/wayland/meta-xwayland.c
index a2fb578abb..0d3468d57e 100644
--- a/src/wayland/meta-xwayland.c
+++ b/src/wayland/meta-xwayland.c
@@ -1286,7 +1286,8 @@ void
 meta_xwayland_shutdown (MetaXWaylandManager *manager)
 {
 #ifdef HAVE_XSETIOERROREXITHANDLER
-  MetaX11Display *x11_display = meta_get_display ()->x11_display;
+  MetaDisplay *display = meta_get_display ();
+  MetaX11Display *x11_display;
 #endif
   char path[256];
 
@@ -1294,8 +1295,12 @@ meta_xwayland_shutdown (MetaXWaylandManager *manager)
 
   XSetIOErrorHandler (x_io_error_noop);
 #ifdef HAVE_XSETIOERROREXITHANDLER
-  XSetIOErrorExitHandler (meta_x11_display_get_xdisplay (x11_display),
-                          x_io_error_exit_noop, NULL);
+  x11_display = display->x11_display;
+  if (x11_display)
+    {
+      XSetIOErrorExitHandler (meta_x11_display_get_xdisplay (x11_display),
+                              x_io_error_exit_noop, NULL);
+    }
 #endif
 
   meta_xwayland_terminate (manager);