File u_dri2_fix-detection-of-wrong-prime_id-in-getscreenprime.patch of Package xorg-x11-server.582

Subject: [PATCH] dri2: Fix wrong prime_id detection in GetScreenPrime.
Author: Michal Srb <msrb@suse.com>
Patch-Mainline: To be upstreamed
References: bnc#846352

Checking the iterating variable ("slave") against null can not detect if the
xorg_list_for_each_entry finished without break being invoked - it will be
always non-null. This caused segfault whenever someone tried to use DRI_PRIME
with incorrect id.

Restructurize it to work as expected.

diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c
index 729a323..5b2c662 100644
--- a/hw/xfree86/dri2/dri2.c
+++ b/hw/xfree86/dri2/dri2.c
@@ -156,11 +156,9 @@ GetScreenPrime(ScreenPtr master, int prime_id)
 
         ds = DRI2GetScreen(slave);
         if (ds->prime_id == prime_id)
-            break;
+            return slave;
     }
-    if (!slave)
-        return master;
-    return slave;
+    return master;
 }
 
 static DRI2ScreenPtr