Hello,
Please review fix for JDK9:
bug: https://bugs.openjdk.java.net/browse/JDK-8027639
webrev: http://cr.openjdk.java.net/~ssadetsky/8027639/webrev.00/
When the Swing repaint manager paints Swing to a separate off-screen
buffer the root window is not painted. So in case of non-opaque root
window having transparent background the repainted buffer area
transparency is not restored and previously visible Swing components can
remain visible.
The solution is to paint the root window's background to the repainted
area in case the root window is non-opaque.
--Semyon
