diff -r dee5afe5301f -r 3f74d0d4af4c src/opengl/qglpaintdevice_p.h
--- a/src/opengl/qglpaintdevice_p.h	Mon Mar 15 12:43:09 2010 +0200
+++ b/src/opengl/qglpaintdevice_p.h	Thu Apr 08 14:19:33 2010 +0300
@@ -75,6 +75,7 @@
     virtual QGLContext* context() const = 0;
     virtual QGLFormat format() const;
     virtual QSize size() const = 0;
+    virtual bool alphaRequested() const;
 
     // returns the QGLPaintDevice for the given QPaintDevice
     static QGLPaintDevice* getDevice(QPaintDevice*);