PyQt & QML ownership problem - reversed

pyqt_qml_ownership_reversed.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

# this code is runnable in both Python 2 and 3

from __future__ import print_function
import os
import sys
import signal
from PyQt5.QtGui import QGuiApplication
from PyQt5.QtQuick import QQuickView
from PyQt5.QtCore import QUrl, QObject, pyqtProperty
from PyQt5.QtQml import qmlRegisterType
import sip


class Dummy(QObject):
    counter = 0

    def __init__(self, parent=None):
        super(Dummy, self).__init__(parent)
        self._number = Dummy.counter
        Dummy.counter += 1
        print("Instantiated", self._number)

        # comment out this line and scroll the list to cause a segfault
        sip.transferto(self, self)

    @pyqtProperty(int, constant=True)
    def number(self):
        return self._number

    def __del__(self):
        print("Deleted", self._number)


def run():
    signal.signal(signal.SIGINT, signal.SIG_DFL)

    app = QGuiApplication(sys.argv)

    qmlRegisterType(Dummy, 'Dummy', 1, 0, 'Dummy')

    qml_url = QUrl.fromLocalFile(os.path.join('zzz.qml'))
    view = QQuickView()

    view.setSource(qml_url)

    def quitting():
        print("\n\nquitting")
    app.aboutToQuit.connect(quitting)

    view.show()

    return_code = app.exec_()
    print("exited event loop")
    sys.exit(return_code)
    print("this never prints, as expected, however process remains running")


if __name__ == '__main__':
    run()

zzz.qml

import QtQuick 2.2
import Dummy 1.0


Item {

    Text {
        x: 50
        text: "<-- scroll this list"
    }

    ListView {
        width: 30
        height: 80
        spacing: 1
        cacheBuffer: 0

        model: 30

        delegate: Rectangle {
            width: 30
            height: 14
            color: "gray"
            property var pleaseKeepMe: Dummy {}
            Component.onDestruction: console.log("Killing", index)
            Text {
                text: pleaseKeepMe.number
            }
        }

    }
}