Drag & Drop of element in Outline view claims to copy but moves it instead

1. Open a QML file.
2. Show the Outline view in Creator's sidebar.
3. Start dragging an element (item, property) in the Outline view.
4. Press Ctrl key.
   The small arrow next to the mouse pointer turns to a plus sign, indicating that the element will be copied.
5. Drop the element.
   It will be moved, not copied.

When dropping an element while pressing Ctrl key, the item should be copied to it's new location. If this is not possible for a valid reason, the mouse pointer should not show a plus sign.