[PyQt] Qthread segmentation fault

[lucaberto at libero.it]

Hello i get segmentation fault from a small client for connect to irc server here is a part of the code:

class Form(QWidget, Ui_Form):
    """
    Class documentation goes here.
    """
    def __init__(self, parent = None):
        """
        Constructor
        """

        super(Form, self). __init__(parent)
        self.socket = QtNetwork.QTcpSocket()
        self.connect(self.socket,  QtCore.SIGNAL("connected()"),
self.connessione)
        self.connect(self.socket,  QtCore.SIGNAL("readyRead()"),
self.leggo_risposta)
        self.connect(self.socket, QtCore.SIGNAL("disconnected"),
self.sconnesso)
        self.connect(self.socket, QtCore.SIGNAL("error
(Qtcore.QAbsatctSocket::SocketError)"), self.server_errore)
        self.lu = Luca()
        self.sock = QtNetwork.QTcpSocket()
        self.connect(self.sock,  QtCore.SIGNAL("connected()"),
self.conn_sock_due)
        self.connect(self.sock,  QtCore.SIGNAL("readyRead()"),
self.inizio)
        self.connect(self.sock, QtCore.SIGNAL("disconnected"),
self.sconnesso)
        self.connect(self.sock, QtCore.SIGNAL("error
(Qtcore.QAbsatctSocket::SocketError)"), self.server_errore)

----------------------------------------------
This part must run because is user for the pong reply to the ping server:

    def leggo_risposta(self):
        while self.socket.bytesAvailable()>0:
            cosa_leggo = self.socket.readData
(self.socket.bytesAvailable())
            self.textEdit.append(cosa_leggo)
            if 'PING' in str(cosa_leggo):
                if len(str(cosa_leggo)) < 20:
                    frase_pong = ('PONG :' + cosa_leggo[6:-2]+'\n')
                    self.textEdit.append(frase_pong)
                    self.socket.writeData(frase_pong)
                    app.processEvents()
                else:
                    frase_pong = ('PONG :' + cosa_leggo[6:28]+'\n')
                    self.textEdit.append(frase_pong)
                    self.socket.writeData(frase_pong)
                    app.processEvents()
    def inizio(self):
         self.lu.start()
------------------------------------------------------------------------------------
here the thread start for the download of the file, 

class Luca(QtCore.QThread):
    def __init__(self, parent=None):
        super(Luca, self).__init__(parent)
        self.lunghezza = ''
        self.sock = ''
        self.salvataggio = ''

    def run(self):
        l_fil = self.salvataggio.tell()
        while l_fil < (self.lunghezza):
            if self.sock.bytesAvailable()>0:
                dati = self.sock.readData(self.sock.bytesAvailable())
                self.salvataggio.write(dati)
                l_fil = self.salvataggio.tell()

This is only a part of the code.

Regards

Luca