added check for fb==NULL

diff --git a/src/mesa/state_tracker/st_cb_flush.c b/src/mesa/state_tracker/st_cb_flush.c
index eb47e75b4037b1c4c829ff88fe538b81a4160235..819957a1ee6fe5f8001bfade2fbee2e45bf469bf 100644 (file)
--- a/src/mesa/state_tracker/st_cb_flush.c
+++ b/src/mesa/state_tracker/st_cb_flush.c
@@ -55,7 +55,9 @@ void st_flush( struct st_context *st )
     */
    st->pipe->flush( st->pipe, 0 );
 
-   
+   if (!fb)
+      return;
+
    /* XXX: temporary hack.  This flag should only be set if we do any
     * rendering to the front buffer.
     */