From 3dba171f5e82101aa8ea2e47d2253c3410907f6a Mon Sep 17 00:00:00 2001
From: Michal Srb <msrb@suse.com>
Date: Tue, 15 Apr 2014 18:54:35 +0300
Subject: [PATCH] dri2: Fix detection of wrong prime_id in GetScreenPrime.

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

Restructurize the GetScreenPrime to work as expected.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
---
 hw/xfree86/dri2/dri2.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c
index 76708cabc..6dd77963c 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