The documentation of QStackedWidget::removeWidget explains that:
"Ownership of widget reverts to the application." ;however, QStackedWidget actually continues to retain ownership of widget even after removeWidget() is called.

Upon adding a widget to a QStackedWidget, the parent of the added widget is set to the QStackedWidget. Once the widget is removed from the stacked widget, the widget continues to be parented to the QStackedWidget.

This contradicts the bug fix in the documentation for bug 10934.