1. Drag the orange square over the blue square.
2. Without releasing the drag, click the middle mouse button.
3. If the platform's normal behaviour is to cancel a drag (eg. Windows and Unix+KDE), then the drag should be cancelled;
   - The drag placeholder should disappear, and the cursor should return to the normal mouse cursor.
   - Move the mouse over the pink square and release the drag. The mouse cursor should remain the normal mouse cursor.
4. If the platform's normal behaviour is not to cancel a drag (eg. Mac and Unix+Gnome), then the drag should not be cancelled;
   - The drag placeholder should not disappear, and the cursor should be the no-drop cursor.
   - Move the mouse over the pink square and release the drag. The drag placeholder should disappear, and the cursor should return to the normal mouse cursor.
5. Fail in either case if an inappropriate middle click function begins (eg. paste-and-go).