In /src/share/classes/sun/awt/RepaintArea.java, we are potentially
leaking a Graphics. In the code below, the test for isEmpty()
should be done inside the try-finally block in order to make sure the
graphics obtained by use of comp.getGraphics() is properly disposed.

    public void paint(Object target, boolean isClearRectOnPaint) {
        Component comp = (Component)target;
        Graphics g = comp.getGraphics();
        if (g == null || isEmpty()) {
            return;
        }
        try {
            RepaintArea ra = this.cloneAndReset();
            int numRects = ra.rectangleList.size();
            union[HORIZONTAL] = union[VERTICAL] = null;
            for (int nRect = 0; nRect < numRects; nRect++) {
                Rectangle r = (Rectangle) ra.rectangleList.removeFirst();
                int addTo = (r.width > r.height) ? HORIZONTAL : VERTICAL;
                if (union[addTo] == null) {
                    union[addTo] = r;
                } else {
                    union[addTo].add(r);
                }
            }
            if(union[HORIZONTAL] != null && union[VERTICAL] != null) {
                int square = ra.width * ra.height;
                int benefit = square - union[HORIZONTAL].width*union[HORIZONTAL].height
                    - union[VERTICAL].width*union[VERTICAL].height;
                // if benefit is comparable with bounding box
                if (MAX_BENEFIT_RATIO * benefit > square) {
                    paintRect(comp, g, union[HORIZONTAL], isClearRectOnPaint);
                    paintRect(comp, g, union[VERTICAL], isClearRectOnPaint);
                    return;
                }
            }
            paintRect(comp, g, ra, isClearRectOnPaint);
        } finally {
            g.dispose();
        }
    }