Bug 129755 [Decorators] CompositeImageDescriptor: Problem on overlay with transparent areas in PNG
bundles/org.eclipse.jface/src/org/eclipse/jface/resource/CompositeImageDescriptor.java
pixel = alloc(out, r, g, b);
                            imageData.setPixel(xx, yy, pixel);
                        }
                    }
                }
            }
            return;
        }
        
        int map[] = new int[256];
        for (int i = 0; i < map.length; i++) {
			map[i] = -1;
		}
        
        if (src.getTransparencyType() == SWT.TRANSPARENCY_MASK) {
            ImageData mask = src.getTransparencyMask();
            for (int y = 0; y < src.height; y++) {
                for (int x = 0; x < src.width; x++) {
                    if (mask.getPixel(x, y) != 0) {
                        int xx = x + ox;
                        int yy = y + oy;
                        if (xx >= 0 && xx < imageData.width && yy >= 0
                                && yy < imageData.height) {
                            int pixel = src.getPixel(x, y);
                            int newPixel = map[pixel];
                            if (newPixel < 0) {
                                RGB c = palette.getRGB(pixel);
                                map[pixel] = newPixel = alloc(out, c.red,
                                        c.green, c.blue);
                            }