From 3147fa775c7e2a933dc74af1372a3318e77d3218 Mon Sep 17 00:00:00 2001
From: Zou Nan hai <nanhai.zou@intel.com>
Date: Tue, 19 Aug 2008 16:20:16 +0800
Subject: [PATCH]   Fix from He Shuang(shuang.he@intel.com),  
 XvMCDestroyContext to check pointer valid

---
 src/xvmc/intel_xvmc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/xvmc/intel_xvmc.c b/src/xvmc/intel_xvmc.c
index 0301efac..f708ee79 100644
--- a/src/xvmc/intel_xvmc.c
+++ b/src/xvmc/intel_xvmc.c
@@ -450,11 +450,12 @@ Status XvMCCreateContext(Display *display, XvPortID port,
 Status XvMCDestroyContext(Display *display, XvMCContext *context)
 {
     Status ret;
-    int screen = DefaultScreen(display);
+    int screen;
 
     if (!display || !context)
         return XvMCBadContext;
 
+    screen = DefaultScreen(display);
     ret = (xvmc_driver->destroy_context)(display, context);
     if (ret) {
 	XVMC_ERR("destroy context fail\n");