Crash during SVG rendering

#include <QGuiApplication>
#include <QSvgRenderer>
#include <QPainter>
#include <QDebug>

int main(int argc, char *argv[])
{
    QGuiApplication a(argc, argv);

    const QString svg =
        "<svg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg' xmlns:xlink='http://www.w3.org/1999/xlink'>"
        "   <linearGradient id='lg1' xlink:href='#lg3'/>"
        "   <linearGradient id='lg3' xlink:href='#lg4'/>"
        "   <linearGradient id='lg4' xlink:href='#lg1'/>"
        "   <rect x='20' y='20' width='160' height='160' fill='url(#lg4)'/>"
        "</svg>";

    QSvgRenderer render(svg.toUtf8());
    qDebug() << render.isValid(); // Ok

    QImage img(200, 200, QImage::Format_ARGB32);
    QPainter p(&img);
    render.render(&p); // An endless loop in QSvgGradientStyle::resolveStops()
    p.end();

    return 0;
}