QGraphicsItem::cursor does not implement the documented behavior correctly

The QGraphicsItem::cursor documentation suggests that "if no cursor has been set, the parent's cursor is used." This is not true, as the attached example clearly shows: On my machine with openSUSE packages of Qt 4.6 (which identify themselves as libqt4-4.5.80+4.6.20091028-1.1), line 30 works as expected, while line 31 does not.