QApplication::mouseButtons out of sync after drag operation

QApplication's internal state gets out of sync with respect to mouseButtons. This happens after a Drop has occured. The QEvent::MouseButtonRelease is never sent for the mouse release which triggered the drop.

I've attached a modification of the standard dnd demo which demonstrates. The small window shows the state of the buttons, if you click-hold-release in an empty spot it toggles on and off normally. if you click on an image it triggers the DnD and the LMB state gets stuck on.