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.

1 files changed, 4 insertions, 3 deletions

diff --git a/src/glx/dri2_glx.c b/src/glx/dri2_glx.c
index 4fbe9496b11..be8671d9069 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);
 }