QQuickView, Memory leak of QOpenGLContextGroup object

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QQuickView w;
    w.show();
    int ret = a.exec();

    int nCrtDbgFlag = _CrtSetDbgFlag(_CRTDBG_REPORT_FLAG);
    nCrtDbgFlag |= _CRTDBG_LEAK_CHECK_DF;
    _CrtSetDbgFlag(nCrtDbgFlag);

    return ret;
}