diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c index 7265f786a9..c13b9a88b8 100644 --- a/gdk/gdkwindow.c +++ b/gdk/gdkwindow.c @@ -6266,7 +6266,7 @@ gdk_window_scroll (GdkWindow *window, gint dy) { GdkWindow *impl_window; - cairo_region_t *copy_area, *noncopy_area; + cairo_region_t *copy_area, *noncopy_area, *old_layered_area; cairo_region_t *old_native_child_region, *new_native_child_region; GList *tmp_list; @@ -6280,6 +6280,7 @@ gdk_window_scroll (GdkWindow *window, gdk_window_flush_if_exposing (window); + old_layered_area = cairo_region_copy (window->layered_region); old_native_child_region = collect_native_child_region (window, FALSE); if (old_native_child_region) { @@ -6320,7 +6321,11 @@ gdk_window_scroll (GdkWindow *window, impl_window = gdk_window_get_impl_window (window); /* Calculate the area that can be gotten by copying the old area */ - copy_area = cairo_region_copy (window->clip_region); + if (window->has_alpha_background) + copy_area = cairo_region_create (); /* Copy nothing for alpha windows */ + else + copy_area = cairo_region_copy (window->clip_region); + cairo_region_subtract (copy_area, old_layered_area); if (old_native_child_region) { /* Don't copy from inside native children, as this is copied by @@ -6334,6 +6339,7 @@ gdk_window_scroll (GdkWindow *window, } cairo_region_translate (copy_area, dx, dy); cairo_region_intersect (copy_area, window->clip_region); + cairo_region_subtract (copy_area, window->layered_region); /* And the rest need to be invalidated */ noncopy_area = cairo_region_copy (window->clip_region); @@ -6355,6 +6361,7 @@ gdk_window_scroll (GdkWindow *window, gdk_window_invalidate_region_full (window, noncopy_area, TRUE, CLEAR_BG_ALL); cairo_region_destroy (noncopy_area); + cairo_region_destroy (old_layered_area); if (old_native_child_region) {