From b6ab41d131eebc03f7f48373f81daa1d65ffb4c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20H=C3=B6glund?= <fredrik@kde.org>
Date: Wed, 27 Jan 2010 16:26:41 +0000
Subject: [PATCH] Don't crash in PaintUtils::transition() if the pixmap doesn't
 have a paint engine.

This is sometimes the case when called from AbstractTaskItem::drawTask().

svn path=/trunk/KDE/kdelibs/; revision=1081054
---
 paintutils.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/paintutils.cpp b/paintutils.cpp
index 2fe794d4a..4becf2c1a 100644
--- a/paintutils.cpp
+++ b/paintutils.cpp
@@ -196,8 +196,10 @@ QPixmap transition(const QPixmap &from, const QPixmap &to, qreal amount)
 
 
     // If the native paint engine supports Porter/Duff compositing and CompositionMode_Plus
-    if (from.paintEngine()->hasFeature(QPaintEngine::PorterDuff) &&
-        from.paintEngine()->hasFeature(QPaintEngine::BlendModes)) {
+    QPaintEngine *paintEngine = from.paintEngine();
+    if (paintEngine && 
+        paintEngine->hasFeature(QPaintEngine::PorterDuff) &&
+        paintEngine->hasFeature(QPaintEngine::BlendModes)) {
 
         QPainter p;
         p.begin(&targetPixmap);
@@ -216,7 +218,7 @@ QPixmap transition(const QPixmap &from, const QPixmap &to, qreal amount)
     }
 #if defined(Q_WS_X11) && defined(HAVE_XRENDER)
     // We have Xrender support
-    else if (from.paintEngine()->hasFeature(QPaintEngine::PorterDuff)) {
+    else if (paintEngine && paintEngine->hasFeature(QPaintEngine::PorterDuff)) {
         // QX11PaintEngine doesn't implement CompositionMode_Plus in Qt 4.3,
         // which we need to be able to do a transition from one pixmap to
         // another.