[gtk/gtk-3-22: 1/2] wayland: Drop cairo surfaces when withdrawing

[Matthias Clasen <matthiasc src gnome org>]

commit 3bd7b379c8d2c7e57ce22501420791c4bfcf24ca
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Tue Jan 30 13:57:35 2018 +0100

    wayland: Drop cairo surfaces when withdrawing
    
    If a window 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_window_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/gdkwindow-wayland.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gdk/wayland/gdkwindow-wayland.c b/gdk/wayland/gdkwindow-wayland.c
index 9ee4fe2be4..38c23c2069 100644
--- a/gdk/wayland/gdkwindow-wayland.c
+++ b/gdk/wayland/gdkwindow-wayland.c
@@ -2600,6 +2600,7 @@ gdk_wayland_window_hide_surface (GdkWindow *window)
   unset_transient_for_exported (window);
 
   _gdk_wayland_window_clear_saved_size (window);
+  drop_cairo_surfaces (window);
   impl->pending_commit = FALSE;
   impl->mapped = FALSE;
 }
@@ -2916,7 +2917,6 @@ gdk_wayland_window_destroy (GdkWindow *window,
   g_return_if_fail (!foreign_destroy);
 
   gdk_wayland_window_hide_surface (window);
-  drop_cairo_surfaces (window);
 }
 
 static void