From 3ea8f70792b62c70bfcae97b970e3830d85c5d72 Mon Sep 17 00:00:00 2001
From: Johannes Schickel <lordhoto@scummvm.org>
Date: Tue, 2 Sep 2008 13:11:54 +0000
Subject: [PATCH] Handle OSystem::lockScreen fail in default
 OSystem::clearScreen implementation.

svn-id: r34276
---
 common/system.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/common/system.cpp b/common/system.cpp
index d0548cdd2d6..863f395671e 100644
--- a/common/system.cpp
+++ b/common/system.cpp
@@ -115,7 +115,8 @@ Common::EventManager *OSystem::getEventManager() {
 
 void OSystem::clearScreen() {
 	Graphics::Surface *screen = lockScreen();
-	memset(screen->pixels, 0, screen->h * screen->pitch);
+	if (screen && screen->pixels)
+		memset(screen->pixels, 0, screen->h * screen->pitch);
 	unlockScreen();
 }