gistfile1.txt

void renderSubtreeToImage(ImageBuffer* image, RenderObject* item)
{
    ASSERT(item);
    ASSERT(image);
    ASSERT(image->context());
    RenderObject::PaintInfo info(image->context(), IntRect(), PaintPhaseForeground, 0, 0, 0);

    // FIXME: isSVGContainer returns true for RenderSVGViewportContainer, so if this is ever
    // called with one of those, we will read from the wrong offset in an object due to a bad cast.
    RenderSVGContainer* svgContainer = 0;
    if (item && item->isSVGContainer())
        svgContainer = toRenderSVGContainer(item);

    bool drawsContents = svgContainer ? svgContainer->drawsContents() : false;
    if (svgContainer && !drawsContents)
        svgContainer->setDrawsContents(true);

    item->layoutIfNeeded();
    item->paint(info, 0, 0);

    if (svgContainer && !drawsContents)
        svgContainer->setDrawsContents(false);
}