Crash during quit if native widget's grandparent is null

In this test app, I have a QTabWidget with 2 widgets. Then I created a native widget with a normal QWidget as its container. Initially, this container  is added into one of the tab widget. When I switch the tab widget, I reparent it to the widget I am showing. However, the software crash when I quit the application while the parent's widget of the container is set to nullptr.

Step to reproduce:

1) Click on Widget 2

2) Quit the app

main.cpp