Fix: Widgets that become top-level widgets may crash the application

You can reproduce the bug with the QMainWindow demo application: Just
dock the toolbar on the left side, then try to drag the bar back to
the top and observe that the application crashes.

This happens, because the toolbar becomes a top-level widget during the
dragging action and therefore some data structures like a window are
created. After the toolbar has been docked, it loses its top-level state
and the window object is destroyed. The same is not true for the backing
store structure, which still keeps a pointer to the destroyed window.
When the toolbar is dragged the next time, a new window object is created,
but the backing store tries to access the deleted one. Crash occurs.

Change-Id: I0d1ffc04c19ec14654ceb62a0d3cf7cf65cb952d
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>

0 files changed, 0 insertions, 0 deletions