C++ Qt Emit Bug

--------  in mqmessagemanager.cpp --------------------------

// This is the static wrapper for the class
// The class comes from a gpointer (void*) data
// And it's converted to a class pointer.
// Then we just simply call a method.

// Since the call back comes from glib is a plain pthread thread.

static gboolean callbackWrapper(SG64ZeroMQ* mq, ThriftStruct* message, gpointer data, GError **error) {
    qDebug("Message received");
    MQMessageManager* self = static_cast<MQMessageManager*>(data);

    fflush(stdout);
    return self->processMessage(mq, message, error);
}


// Other method of the class
bool MQMessageManager::processMessage(SG64ZeroMQ* mq, ThriftStruct* message, GError **error)
{
    mqPayload *payload=NULL;
    mqCardEvent *cardEvent = NULL;
    mqMessage *msg=NULL;
    QString str;
    g_return_val_if_fail (THRIFT_IS_STRUCT (message), FALSE);

//    if(QThread::self()==NULL){
//        qDebug("Not in thread");
//    }

    if(IS_MQ_MESSAGE(message))
      msg=MQ_MESSAGE(message);
    switch(msg->type){
      case MQ_MESSAGE_TYPE_COMMAND:
        puts("Received a command");
        break;
      case MQ_MESSAGE_TYPE_GPS_EVENT:
        puts("Received a gps event");
        break;
      case MQ_MESSAGE_TYPE_CARD_EVENT:
        if(IS_MQ_CARD_EVENT(msg->payload->card_event)){
            cardEvent = msg->payload->card_event;
            if(cardEvent!=NULL && cardEvent->atr!=NULL){
                QByteArray array((char *)cardEvent->atr->data, (int) cardEvent->atr->len);
                QString atr = QString(array.toHex());
                qDebug("ATR found of size %d, %s", cardEvent->atr->len, atr.toLatin1().data());
//                emit valid(atr);
                emit cardValidationSuccess(); // It breaks here!!!!!!!!!!!!!
                qDebug("Emitted valid signal");
                QThread *thread = QThread::currentThread();
                qDebug("Emitted valid signal %x", thread);

//                thread->
//                QMetaObject::invokeMethod(this, "valid", Qt::QueuedConnection,
//                                          Q_ARG(QString, atr));
            }
        }
        break;
      default:
        printf("Message of type %i cannot be managed\n", msg->type);
        break;
    }
    return TRUE;
}



--------  in mqmessagemanager.cpp --------------------------




--------  in mainwindow.cpp --------------------------


// I just connect few signals
// Can even move (by comments) the class to a new thread
// but it makes no difference on the bug. It breaks the same
void MainWindow::startManagement()
{
    ui->textLabel->show();
    qDebug("Starting management");

//    QThread *rfidThread = new QThread(this);
//    QObject::connect(rfidThread, SIGNAL(started()), nfcReader, SLOT(startrfid()));
    if(!QObject::connect(mqMessageManager, SIGNAL(cardValidationSuccess()), this, SLOT(displayValid()),Qt::QueuedConnection)){
        qDebug("Cannot connect signal");
    }

    QObject::connect(mqMessageManager, SIGNAL(valid(QString)), this, SLOT(displayValid(QString)), Qt::BlockingQueuedConnection);
//    QObject::connect(mqMessageManager, SIGNAL(invalid(QString)), this, SLOT(displayInvalid(QString)), Qt::BlockingQueuedConnection);
//    QObject::connect(mqMessageManager, SIGNAL(concession(QString)), this, SLOT(displayConcession(QString)), Qt::BlockingQueuedConnection);
//    mqMessageManager->moveToThread(rfidThread);
//    rfidThread->start( );
    QTimer::singleShot(0, mqMessageManager, SIGNAL(startMQMessenging()));

}


void MainWindow::displayValid()
{


    green_light();
    QPixmap pixmap(qApp->applicationDirPath()+"/images/valid.png");
    ui->imageLabel->setPixmap(pixmap);
    ui->imageLabel->setMask(pixmap.mask());
    ui->textLabel->setText(message);
    ui->textLabel->show();
    play_good();

    timer.start(SCREENTIME);
}



--------  in mainwindow.cpp --------------------------






-------------------------------------------------------
-- If I add this it does not break
-------------------------------------------------------



class mqmessagebridge: public QObject {
    Q_OBJECT
    MQMessageManager *manager;
    QThread *thread;
public:
    mqmessagebridge(MQMessageManager* mq_, QThread *_currThread) : manager(mq_), thread(_currThread) {}

public slots:
  void processMessage(SG64ZeroMQ* mq, ThriftStruct* message, GError **error) {
      qDebug("Thread of the bridge %x", QThread::currentThread()); // Thread of the bridge c00024f0
      qDebug("Thread of the stored class in bridge %x", thread);   // Thread of the stored class in bridge d400eb80
//      manager->moveToThread(QThread::currentThread()); //  QObject::moveToThread: Cannot move objects with a parent
      manager->processMessage(mq,message,error);
  }
};



--------  in mqmessagemanager.cpp --------------------------

// This is the static wrapper for the class
// The class comes from a gpointer (void*) data
// And it's converted to a class pointer.
// Then we just simply call a method.

// Since the call back comes from glib is a plain pthread thread.

static gboolean callbackWrapper(SG64ZeroMQ* mq, ThriftStruct* message, gpointer data, GError **error) {
    qDebug("Message received");
    mqmessagebridge *self = static_cast<mqmessagebridge*>(data);
    fflush(stdout);
    qDebug("Thread of the call %x", QThread::currentThread());

    self->processMessage(mq, message, error);
    return TRUE;
}