Access Violation in QAbstractItemView::setModel() in Qt6

QAbstractItemView::setModel(QAbstractItemModel *model) may cause undefined behaviour if model=0 is passed into setModel.

Reason is the following line:

d->model = (model ? model : QAbstractItemModelPrivate::staticEmptyModel());

This line looks like it makes sure that d->model is non-null but that's not true, as the assignment from QAbstractItemModelPrivate::staticEmptyModel() may assign a null pointer (e.g. in case we are in the midst of a shutdown / destruction of the view's parent).

Thus all following code needs to check if d->model != 0 to avoid access violations, but some lines later there is:

QItemSelectionModel *selection_model = new QItemSelectionModel(d->model, this);
connect(d->model, &QAbstractItemModel::destroyed, selection_model, &QItemSelectionModel::deleteLater);

which fails with a crash.