Event behavior for QEvent::MouseButtonDblClick changed since Qt 4

4.8.6 
#0 MouseButtonPress    widget QWidget(0xd4caa0, name = "Widget") 
#1 MouseButtonRelease  widget QWidget(0xd4caa0, name = "Widget") 
#2 MouseButtonDblClick widget QWidget(0xd4caa0, name = "Widget") 
#3 MouseButtonRelease  widget QWidget(0xd4caa0, name = "Widget") 

5.2.1 
#0 MouseButtonPress    window QWidgetWindow(0x1bd4f80, name = "WidgetWindow") 
#0 MouseButtonPress    widget QWidget(0x1bd47f0, name = "Widget") 
#1 MouseButtonRelease  window QWidgetWindow(0x1bd4f80, name = "WidgetWindow") 
#1 MouseButtonRelease  widget QWidget(0x1bd47f0, name = "Widget") 
#2 MouseButtonPress    window QWidgetWindow(0x1bd4f80, name = "WidgetWindow") 
#2 MouseButtonPress    widget QWidget(0x1bd47f0, name = "Widget") 
#3 MouseButtonDblClick window QWidgetWindow(0x1bd4f80, name = "WidgetWindow") 
#3 MouseButtonDblClick widget QWidget(0x1bd47f0, name = "Widget") 
#4 MouseButtonRelease  window QWidgetWindow(0x1bd4f80, name = "WidgetWindow") 
#4 MouseButtonRelease  widget QWidget(0x1bd47f0, name = "Widget") 

5.3.1 (with fix applied)
#0 MouseButtonPress    window flags:0 src:0 QWidgetWindow(0xab9bf0, name = "WidgetWindow")
#0 MouseButtonPress    widget flags:0 src:0 QWidget(0xab68c0, name = "Widget")
#1 MouseButtonRelease  window flags:0 src:0 QWidgetWindow(0xab9bf0, name = "WidgetWindow")
#1 MouseButtonRelease  widget flags:0 src:0 QWidget(0xab68c0, name = "Widget")
#2 MouseButtonPress    window flags:1 src:0 QWidgetWindow(0xab9bf0, name = "WidgetWindow")
#3 MouseButtonDblClick window flags:0 src:0 QWidgetWindow(0xab9bf0, name = "WidgetWindow")
#2 MouseButtonDblClick widget flags:0 src:0 QWidget(0xab68c0, name = "Widget")
#4 MouseButtonRelease  window flags:0 src:0 QWidgetWindow(0xab9bf0, name = "WidgetWindow")
#3 MouseButtonRelease  widget flags:0 src:0 QWidget(0xab68c0, name = "Widget")

#include <qapplication.h>
#include <qevent.h>
#include <qwidget.h>

class EventDumper: public QWidget {
public:
    EventDumper(): QWidget( 0 ) {}

    virtual bool event( QEvent *ev ) {
        const QEvent::Type et = ev->type();
        switch ( et ) {
            case QEvent::MouseButtonDblClick:
                qDebug("MouseButtonDblClick");
                return true;
            case QEvent::MouseButtonPress:
                qDebug("MouseButtonPress");
                return true;
            case QEvent::MouseButtonRelease:
                qDebug("MouseButtonRelease");
                return true;
            default:
                break;
        }
        return QWidget::event( ev );
    }
};

int main( int argc, char **argv )
{
    QApplication app( argc, argv );
    EventDumper ed;
    ed.show();
    return app.exec();
}