If a target object is destroyed QPropertyAnimationPrivate::targetValue
reflects this while QPropertyAnimationPrivate::target stays unchanged.
QPropertyAnimation::setTargetObject() checks if a new target matches
QPropertyAnimationPrivate::target - to bad if the former target has
been destroyed in the meanwhile but the new one has the same memory
address. targetValue is not updated in this case. It will still point
to null and QPropertyAnimation::targetObject() returns 0.
This is not just a theoretical problem - we stubled upon this in
Harmattan when suddenly animations complained that they are having no
target.
Change-Id: Ib4a9c234d04d6f8a3f7aed251d5e79471d95168a
Reviewed-by: Leonardo Sobral Cunha <leo.cunha@nokia.com>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
d0cb57a4e7