Enumerating QAction in a QMenuBar

[cionci]

I want to enumerate at runtime all QAction in a QMenuBar.
My first try was to enumerate QAction in a QMenu.

void MainWindow::buildAutoCompletion(QMenu * menu)
{
    QList<QAction *> actions = menu->actions();
    QList<QAction *>::const_iterator it = actions.begin();
    for(; it != actions.end(); it++)
    {
        QAction *action = *it;
        ui->plainTextEdit->setPlainText(ui->plainTextEdit->toPlainText() + action->text());
    }
}
 
void MainWindow::on_pushButton_clicked()
{
    buildAutoCompletion(ui->menuFile);
    buildAutoCompletion(ui->menuModifica);
}

void MainWindow::buildAutoCompletion(QMenu * menu)
{
    QList<QAction *> actions = menu->actions();
    QList<QAction *>::const_iterator it = actions.begin();
    for(; it != actions.end(); it++)
    {
        QAction *action = *it;
        ui->plainTextEdit->setPlainText(ui->plainTextEdit->toPlainText() + action->text());
    }
}

void MainWindow::on_pushButton_clicked()
{
    buildAutoCompletion(ui->menuFile);
    buildAutoCompletion(ui->menuModifica);
}

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The application crashes when I click on the push button. If I try debugging, application hangs on menu->actions() (as I can see on the stack trace).

Qt 4.5.3 under Linux 64 bit.

Thanks