There were two issues:
- Graphics2D.setClip only works on rectangular shapes.
This means doing a setClip on a non rectangular shape should
basically reset the clip and intersect with the new shape.
- the current clip can be null, so the combineShape method
must handle it.
Change-Id: Id2cd7475e991d8b533ff2e8850cc2c27663f9e52
a7cac5e054