From 3d80f202b06227f7fc03b674f5fbf809c2d1efb2 Mon Sep 17 00:00:00 2001
From: Ryan Pavlik <rpavlik@iastate.edu>
Date: Fri, 28 Oct 2011 09:56:19 -0500
Subject: [PATCH] hw/xwin: Fix possible null ptr deref in
 winMWExtWMDecorateWindow()

Signed-off-by: Ryan Pavlik <rpavlik@iastate.edu>
Reviewed-by: Colin Harrison <colin.harrison@virgin.net>
Reviewed-by: Jon TURNEY <jon.turney@dronecode.org.uk>
---
 hw/xwin/winwin32rootlesswindow.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/xwin/winwin32rootlesswindow.c b/hw/xwin/winwin32rootlesswindow.c
index 214e8954b..fbff83888 100644
--- a/hw/xwin/winwin32rootlesswindow.c
+++ b/hw/xwin/winwin32rootlesswindow.c
@@ -202,7 +202,8 @@ winMWExtWMDecorateWindow (HWND hwnd, LPARAM lParam)
   /* Check if the Windows window property for our X window pointer is valid */
   if ((pRLWinPriv = (win32RootlessWindowPtr)GetProp (hwnd, WIN_WINDOW_PROP)) != NULL)
     {
-      pScreen				= pRLWinPriv->pFrame->win->drawable.pScreen;
+      if (pRLWinPriv != NULL && pRLWinPriv->pFrame != NULL && pRLWinPriv->pFrame->win != NULL)
+        pScreen				= pRLWinPriv->pFrame->win->drawable.pScreen;
       if (pScreen) pScreenPriv		= winGetScreenPriv(pScreen);
       if (pScreenPriv) pScreenInfo	= pScreenPriv->pScreenInfo;
       if (pRLWinPriv && pScreenInfo) winMWExtWMUpdateWindowDecoration (pRLWinPriv, pScreenInfo);