Dragging an internal frame inside jframe leves artefacts with when run with the MetalLookAndFeel.
Steps to reproduce the issue
1.Run Swingset2 demo
2.Switch LAF to MetalLookAndFeel
3.Close all the internal frame (Note that the issue is not reproducible with the existing internal frames)
4.create a new internal frame
5.Drag the internal frame inside the frame, drag around the corners as well.

This issue is not see with the other LAF.
Screenshot is attached