Mesa (master): glx/dri2: Fix dri2CopySubBuffer() again.

[Michel Dänzer]

Module: Mesa
Branch: master
Commit: bd3d2724f51a44b7fc814a5bc43d8ddafa8e3cba
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=bd3d2724f51a44b7fc814a5bc43d8ddafa8e3cba

Author: Michel Dänzer <daenzer at vmware.com>
Date:   Tue Jul 20 12:21:17 2010 +0200

glx/dri2: Fix dri2CopySubBuffer() again.

Only refresh the fake front buffer if there is one, and only destroy the region
once.

Fixes X11 protocol errors reported by 'mcgreg' on IRC.

---

 src/glx/dri2_glx.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/glx/dri2_glx.c b/src/glx/dri2_glx.c
index 4fbe949..be8671d 100644
--- a/src/glx/dri2_glx.c
+++ b/src/glx/dri2_glx.c
@@ -352,13 +352,14 @@ dri2CopySubBuffer(__GLXDRIdrawable *pdraw, int x, int y, int width, int height)
    region = XFixesCreateRegion(psc->base.dpy, &xrect, 1);
    DRI2CopyRegion(psc->base.dpy, pdraw->xDrawable, region,
                   DRI2BufferFrontLeft, DRI2BufferBackLeft);
-   XFixesDestroyRegion(psc->base.dpy, region);
 
    /* Refresh the fake front (if present) after we just damaged the real
     * front.
     */
-   DRI2CopyRegion(psc->base.dpy, pdraw->xDrawable, region,
-		  DRI2BufferFakeFrontLeft, DRI2BufferFrontLeft);
+   if (priv->have_fake_front)
+      DRI2CopyRegion(psc->base.dpy, pdraw->xDrawable, region,
+		     DRI2BufferFakeFrontLeft, DRI2BufferFrontLeft);
+
    XFixesDestroyRegion(psc->base.dpy, region);
 }