diff -r dee5afe5301f -r 3f74d0d4af4c src/gui/painting/qwindowsurface_qws_p.h
--- a/src/gui/painting/qwindowsurface_qws_p.h	Mon Mar 15 12:43:09 2010 +0200
+++ b/src/gui/painting/qwindowsurface_qws_p.h	Thu Apr 08 14:19:33 2010 +0300
@@ -176,6 +176,8 @@
     QImage image() const { return img; }
     QPoint painterOffset() const;
 
+    void beginPaint(const QRegion &rgn);
+
     bool lock(int timeout = -1);
     void unlock();