From 8998f52b97caf4e42439085b9ce63d088bfbaa87 Mon Sep 17 00:00:00 2001
From: "Xiang, Haihao" <haihao.xiang@intel.com>
Date: Wed, 5 Dec 2007 10:31:35 +0800
Subject: [PATCH] Don't Swap buffer if a DRIDrawable is entirely obscured by
 another window.

---
 src/mesa/drivers/dri/common/dri_util.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/mesa/drivers/dri/common/dri_util.c b/src/mesa/drivers/dri/common/dri_util.c
index c30e66f1722..77cbd8109ea 100644
--- a/src/mesa/drivers/dri/common/dri_util.c
+++ b/src/mesa/drivers/dri/common/dri_util.c
@@ -486,6 +486,9 @@ static void driSwapBuffers( __DRInativeDisplay *dpy, void *drawablePrivate )
     __DRIdrawablePrivate *dPriv = (__DRIdrawablePrivate *) drawablePrivate;
     drm_clip_rect_t rect;
 
+    if (!dPriv->numClipRects)
+        return;
+
     dPriv->swapBuffers(dPriv);
 
     /* Check that we actually have the new damage report method */