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

diff --git a/gdk/wayland/gdkwindow-wayland.c b/gdk/wayland/gdkwindow-wayland.c
index 9ee4fe2be462eba9f46f8fa56a19e507e86be0b3..38c23c20698cbc573034dbb048dad781bf4afe54 100644 (file)
--- 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