Need some direction: JDK-8089024

[John Hendrikx]

Please see:

   https://bugs.openjdk.java.net/browse/JDK-8089024

This is a bug which seems to apply transparency twice when a Node has a 
clip set.  I managed to create a small test program that shows the 
problem very clearly, see this image (on Windows):

   https://pasteboard.co/djKKvPVsCfYC.png

Note that the two bottom rows should look identical, but they don't.

If I could get some direction where to look for this problem I might be 
able to solve it.

--John