Wrong cursor when using messagebox inside dropevent

#include <QtWidgets/QMessageBox>
#include <QtCore/QDebug>
#include <QtGui/QDropEvent>
#include <QtGui/QDrag>
#include <QtGui/QClipboard>
#include <QtWidgets/QInputDialog>
#include <QtWidgets/QLabel>
#include <QtWidgets/QApplication>
#include <QtCore/QMimeData>
#include <QtCore/QBuffer>
#include <QtGui/QImage>
#include <QtGui/QPixmap>
//#include <QtGui>
//#include <QtCore>

class MyWidget : public QLabel
{
    Q_OBJECT
public:
    MyWidget()
        : QLabel(0) {
        setMinimumSize(QSize(200, 200));
        setAcceptDrops(true);
    }

protected:
    virtual void mouseMoveEvent(QMouseEvent*) {
        QDrag* drag = new QDrag(this);
        QMimeData* mimeData = new QMimeData;

        mimeData->setText(text());
        drag->setMimeData(mimeData);
        drag->exec();
    }

    virtual void dragEnterEvent(QDragEnterEvent* event) {
        //qDebug() << "dragEnterEvent: " << event->proposedAction();
        event->acceptProposedAction();
    }
    virtual void dragMoveEvent(QDragMoveEvent* event) {
        //qDebug() << "dragMoveEvent: " << event->proposedAction();
        event->acceptProposedAction();
    }

    virtual void dropEvent(QDropEvent* event) {
        const QMimeData* mimeData = event->mimeData();
        if (QMessageBox::question(0, "Confirmation required", "Do you want to paste?",
                                     QMessageBox::Yes | QMessageBox::No) == QMessageBox::Yes) {
            if (mimeData->hasText()) {
                qWarning("retrieving text");
                setText("#" + mimeData->text() + " yo");
            }
}

        qDebug() << "done with data";
        event->acceptProposedAction();
    }
};

int main( int argc, char ** argv )
{
    QApplication app(argc, argv);
    qDebug() << "V: " << qVersion();
    MyWidget w1;
    w1.setText("Drag/drop widget");
    w1.show();

    return app.exec();
}

#include "dnd_modaldlg.moc"