svga: add null vs pointer check in update_need_pipeline()

Based on a patch submitted by Vic Lee.  The other part of his patch
which checked the fs pointer wasn't needed.

This fixes a crash when clear() is called before any VS or FS is set.
But this can only happen when the driver is used without the Mesa
state tracker.

NOTE: This is a candidate for the 8.0 branch.

Reviewed-by: José Fonseca <jfonseca@vmware.com>

diff --git a/src/gallium/drivers/svga/svga_state_need_swtnl.c b/src/gallium/drivers/svga/svga_state_need_swtnl.c
index 32355d1..ce4db8d 100644 (file)
--- a/src/gallium/drivers/svga/svga_state_need_swtnl.c
+++ b/src/gallium/drivers/svga/svga_state_need_swtnl.c
@@ -136,7 +136,7 @@ update_need_pipeline( struct svga_context *svga,
 
    /* EDGEFLAGS
     */
-    if (vs->base.info.writes_edgeflag) {
+    if (vs && vs->base.info.writes_edgeflag) {
       SVGA_DBG(DEBUG_SWTNL, "%s: edgeflags\n", __FUNCTION__);
       need_pipeline = TRUE;
    }