[gtk: 1/2] wayland: Drop cairo surfaces when withdrawing

[Matthias Clasen <matthiasc src gnome org>]

commit 77a5d00047febe4317518ff31e84e5c37499e4ff
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Tue Jan 30 13:57:35 2018 +0100

    wayland: Drop cairo surfaces when withdrawing
    
    If a surface is unmapped by the client while gdk is processing updates,
    (for example Firefox un-mapping its window on Expose events), the
    windowing backend resources might be lost (for example with Wayland)
    which can cause a crash in end_paint().
    
    Make sure we drop the cairo surfaces as well when hiding the surface,
    that will avoid the crash in gdk_surface_impl_wayland_end_paint() when
    trying to attach the staging cairo surface to a released wl_surface,
    these will be recreated when needed when the surface becomes visible
    again and there is no need to keep such buffers around for a surface
    which is not visible anyway.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=793062

 gdk/wayland/gdksurface-wayland.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gdk/wayland/gdksurface-wayland.c b/gdk/wayland/gdksurface-wayland.c
index d91be60e89..dcd9990f63 100644
--- a/gdk/wayland/gdksurface-wayland.c
+++ b/gdk/wayland/gdksurface-wayland.c
@@ -2530,6 +2530,7 @@ gdk_wayland_surface_hide_surface (GdkSurface *surface)
   unset_transient_for_exported (surface);
 
   _gdk_wayland_surface_clear_saved_size (surface);
+  drop_cairo_surfaces (surface);
   impl->pending_commit = FALSE;
   impl->mapped = FALSE;
 }
@@ -2813,7 +2814,6 @@ gdk_wayland_surface_destroy (GdkSurface *surface,
   g_return_if_fail (!foreign_destroy);
 
   gdk_wayland_surface_hide_surface (surface);
-  drop_cairo_surfaces (surface);
 
   if (surface->parent == NULL)
     {