Use-after-free in QWidget hierarcy

void QWidgetPrivate::showChildren(bool spontaneous)
{
    // here!
    QList<QObject*> childList = children;
    for (int i = 0; i < childList.size(); ++i) {
        QWidget *widget = qobject_cast<QWidget*>(childList.at(i));
        if (widget && widget->windowHandle() && !widget->testAttribute(Qt::WA_WState_ExplicitShowHide))
            widget->setAttribute(Qt::WA_WState_Hidden, false);
        if (!widget
            || widget->isWindow()
            || widget->testAttribute(Qt::WA_WState_Hidden))
            continue;
        if (spontaneous) {
            widget->setAttribute(Qt::WA_Mapped);
            widget->d_func()->showChildren(true);
            QShowEvent e;
            QApplication::sendSpontaneousEvent(widget, &e);
        } else {
            if (widget->testAttribute(Qt::WA_WState_ExplicitShowHide))
                widget->d_func()->show_recursive();
            else
                widget->show();
        }
    }
}