From 7c1e1b758eea922eef6c9393fa72d3bb35fbea5c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <kde@martin-graesslin.com>
Date: Sat, 31 Jan 2009 09:56:16 +0000
Subject: [PATCH] Backport (rev 919007): Only clear QLists when they are empty.
 Prevents crashes. CCBUG: 182358

svn path=/branches/KDE/4.2/kdebase/workspace/; revision=919009
---
 effects/coverswitch.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/effects/coverswitch.cpp b/effects/coverswitch.cpp
index b7369a1990..9bba048590 100644
--- a/effects/coverswitch.cpp
+++ b/effects/coverswitch.cpp
@@ -201,8 +201,10 @@ void CoverSwitchEffect::paintScreen( int mask, QRegion region, ScreenPaintData&
             rightIndex = 0;
 
         EffectWindow* frontWindow = tempList[ index ];
-        leftWindows.clear();
-        rightWindows.clear();
+        if( !leftWindows.isEmpty() )
+            leftWindows.clear();
+        if( !rightWindows.isEmpty() )
+            rightWindows.clear();
 
         bool evenWindows = ( tempList.count() % 2 == 0 ) ? true : false;
         int leftWindowCount = 0;