[REG] QGraphicsItem: cached embedded widget item is not repainted when widget is updated

#include <QtGui>

class PushButton : public QPushButton
{
    Q_OBJECT

public:
    PushButton(QWidget *parent = 0) : QPushButton(parent)
    {
        setText("Update the text by clicking me or from my context menu");

        setContextMenuPolicy(Qt::ActionsContextMenu);
        QAction *action = new QAction("Update text", this);
        addAction(action);

        connect(this, SIGNAL(clicked()), this, SLOT(updateText()));
        connect(action, SIGNAL(triggered()), this, SLOT(updateText()));
    }

public slots:
    void updateText()
    {
        static int count = 0;
        setText(QString("foobar %1").arg(count++));
    }
};

#include "main.moc"

int main(int argc, char **argv)
{
    QApplication app(argc, argv);

    PushButton w;
    w.show();

    QGraphicsView view;
    QGraphicsScene *scene = new QGraphicsScene(0, 0, 800, 600);
    QGraphicsProxyWidget *proxy = scene->addWidget(new PushButton);
    proxy->setCacheMode(QGraphicsItem::DeviceCoordinateCache);
    view.setScene(scene);
    view.show();

    return app.exec();
}