add an assertion to operator-> as it always needs to return a non-null pointer
add an assertion to operator-> as it always needs to return a non-null pointer

svn path=/trunk/KDE/kdelibs/phonon/; revision=791565

sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc,sandsmark/phonon-visualization-gsoc