Mouse cursors not restored correcly after a drag operation.

After starting a drag operation with QDrag::exec() the mouse cursor does not return to the original one, expecially if dragging along over a lot of differents window and then cancelling the drag operation itself.

The mouse cursor have to be restored with the following code:

while (QGuiApplication::overrideCursor())  
   QGuiApplication::restoreOverrideCursor();

Note: that loop may be executed a lot of times (maximum peak detected is 14).