blur-effect: Handle failure of background blitting gracefully

`paint_background` already provides a return value in case the blitting
of the framebuffer fails, handle that and fall back to only drawing the
actor in case something goes wrong.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/1000

diff --git a/src/shell-blur-effect.c b/src/shell-blur-effect.c
index c3fb3bc60e68cd69ae12cd0bd5d6aa1c1eb869c7..5e50ab886f75cf48e9b96be9dc29c919ef47fa78 100644 (file)
--- a/src/shell-blur-effect.c
+++ b/src/shell-blur-effect.c
@@ -807,7 +807,9 @@ shell_blur_effect_paint (ClutterEffect           *effect,
               break;
 
             case SHELL_BLUR_MODE_BACKGROUND:
-              paint_background (self, paint_context, &source_actor_box);
+              if (!paint_background (self, paint_context, &source_actor_box))
+                goto fail;
+
               apply_blur (self, paint_context, &self->background_fb, 255);
               break;
             }