Gesture Manager crashes while delivering events to deleted object

Run the attached application. Using a mac laptop touchpad(important!) click
and drag around on the square and make a gesture during the drag. When you send the gesture with the right timing, you get a crash(usually the easiest
gesture is a three finger pinch though Qt seems to think it's a pan). This
seems to happen because the object is deleted between the start of the gesture and completion of the gesture.