Previously, the geometry stored for floating dock widgets
in QPlaceHolderItem::topLevelRect and QDockAreaLayoutInfo::saveState()
included the window frame (frame position/content area size).
This does not work in the case where a floating dock widget is deleted
since the geometry is determined after reparenting the widget when the
frame geometry is no longer available. Change the behavior to store
the geometry excluding frame to avoid such problems and adapt
QDockWidgetPrivate::setWindowState() accordingly.
Task-number: QTBUG-49832
Task-number: QTBUG-45780
Change-Id: I84b5c80df6e1c9e738bbb1407b9047cc84719ce0
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
bece6fa0b9