From 903c51278363db45a42697aba7bf5cc907c758f7 Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Tue, 18 Sep 2012 20:55:15 +0000
Subject: [PATCH] [WIN32K] Allow passing NULL to EngFreeMem, like on Windows.
 Fixes mode switching with cirrus driver on qemu. CORE-6335 #resolve

svn path=/trunk/; revision=57325
---
 reactos/win32ss/gdi/eng/mem.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/reactos/win32ss/gdi/eng/mem.c b/reactos/win32ss/gdi/eng/mem.c
index af6ae914d85..150ed335eaf 100644
--- a/reactos/win32ss/gdi/eng/mem.c
+++ b/reactos/win32ss/gdi/eng/mem.c
@@ -44,7 +44,11 @@ VOID
 APIENTRY
 EngFreeMem(PVOID pvBaseAddress)
 {
-    ExFreePool(pvBaseAddress);
+    /* Windows allows to pass NULL */
+    if (pvBaseAddress)
+    {
+        ExFreePool(pvBaseAddress);
+    }
 }
 
 /*