QApplication destructor doesn't release hidden QMenu window resource

#include <QtWidgets/QApplication>
#include <QtWidgets/QMenu>
#include <QtWidgets/QWidget>
#include <QtCore/QTimer>
#include <Windows.h>

HWND leakedWindow = 0;

class WidgetWithMenu : public QWidget
{
public:
    WidgetWithMenu(QWidget* parent)
        : QWidget(parent)
    {}

    void showEvent(QShowEvent* e) override
    {
        QTimer::singleShot(100, this, [&]() {
            m_pMenu = new QMenu(this);
            m_pMenu->popup(QPoint(0, 0));

            QTimer::singleShot(100, this, [&]() {
                leakedWindow = (HWND)m_pMenu->internalWinId();
                m_pMenu->hide();
                window()->close();

                // QMenu's window is a transient child of toplevel window. But QMenu has no
                // WA_NativeWindow flag. When QApplication destructor call toplevel window
                // destroy(true, true), QMenu is skipped and leak.
            });
        });
    }

private:
    QMenu* m_pMenu = nullptr;
};

int main(int argc, char** argv)
{
    {
        QApplication app(argc, argv);

        QWidget* tlw = new QWidget();
        tlw->resize(640, 480);
        tlw->setStyleSheet("QWidget { background-color: red; }");

        QWidget* child = new WidgetWithMenu(tlw);
        child->setGeometry(0, 0, 100, 100);
        child->setStyleSheet("QWidget { background-color: yellow; }");

        tlw->show();
        app.exec();
    }

    // Qt window proc can still receive messages and crash.
    SendMessage(leakedWindow, WM_SETTINGCHANGE, 0, (LPARAM)TEXT("ThemeChanged"));
    return 0;
}