[mutter] wayland/surface: Don't make destoryed actor reactive

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 19e3c216679a232de3e773fd7624c9eb0253d352
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Dec 3 17:04:42 2018 +0100

    wayland/surface: Don't make destoryed actor reactive
    
    When destructing a xdg_toplevel, we'll disassociate the actor from the
    MetaWaylandSurface, to allow it to animate out. After having done this,
    avoid trying to set it as unreactive when unsetting the window.
    
    This fixes the runtime warning:
    
    clutter_actor_set_reactive: assertion 'CLUTTER_IS_ACTOR (actor)' failed

 src/wayland/meta-wayland-surface.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index 26ee4c256..834d7c8a8 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -1226,6 +1226,7 @@ meta_wayland_surface_set_window (MetaWaylandSurface *surface,
                                  MetaWindow         *window)
 {
   gboolean was_unmapped = surface->window && !window;
+  ClutterActor *actor;
 
   if (surface->window == window)
     return;
@@ -1242,7 +1243,10 @@ meta_wayland_surface_set_window (MetaWaylandSurface *surface,
 
   surface->window = window;
 
-  clutter_actor_set_reactive (CLUTTER_ACTOR (meta_wayland_surface_get_actor (surface)), !!window);
+  actor = CLUTTER_ACTOR (meta_wayland_surface_get_actor (surface));
+  if (actor)
+    clutter_actor_set_reactive (actor, !!window);
+
   sync_drag_dest_funcs (surface);
 
   if (was_unmapped)