The Embedded Dialogs examples crash when close the window.

#include <QtWidgets>

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

   QGraphicsScene scene;

   QComboBox * w = new QComboBox;
   w->addItem("0");
   w->addItem("1");

   scene.addWidget( w );

   QGraphicsView view( &scene );
   view.show();

   return app.exec();
}