From a057c038893b7a9c84524796662de17a97e4437a Mon Sep 17 00:00:00 2001
From: Alexander Larsson <alexl@redhat.com>
Date: Sun, 19 Jul 2009 22:35:25 +0200
Subject: [PATCH] Optimize remove_child_area for children outside region

If a child is totally outside the current region, bail early instead
of doing costly calculations to subtract the child region.
---
 gdk/gdkwindow.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index eeb89325b3..a1fa4505df 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -636,6 +636,10 @@ remove_child_area (GdkWindowObject *private,
       r.width = child->width;
       r.height = child->height;
 
+      /* Bail early if child totally outside region */
+      if (gdk_region_rect_in (region, &r) == GDK_OVERLAP_RECTANGLE_OUT)
+	continue;
+
       child_region = gdk_region_rectangle (&r);
 
       if (child->shape)
-- 
2.30.2