QTcpSocket.readLine causing segmentation failure

[hasnain]

i am using QTcpsocket.readLine to read from a socket in a thread. it is working well otherwise but causing a segmentation failure. this the code:

Header file

#ifndef CLIENTTHREAD_H
#define CLIENTTHREAD_H
#include<QtNetwork/QTcpSocket>
#include<QThread>

class clientThread:public QThread
{
Q_OBJECT
public:
clientThread(QTcpSocket *,QObject *,QString);
// MainWindow *m;
// int index;
QString name;
void run();
signals:
void updatechat(QString,QString);
private slots:
void readFromClient();
private:
QTcpSocket *socket;
};

#endif // CLIENTTHREAD_H

Source File;


#include "clientthread.h"

clientThread::clientThread(QTcpSocket *_socket,QObject *parent,/*int _index*/QString _name):QThread(parent),
socket(_socket),name(_name)
{
connect(socket,SIGNAL(disconnected()),this,SLOT(te rminate()));
}

void clientThread::run(){

char *data;
QString s;
uint i;
i=1024;
qDebug()<<"client thread started";

}

void clientThread::readFromClient(){
char *data;
QString s;
uint i;
i=1024;
socket->readLine(data,i);
emit updatechat(tr(data),name);
}

Any Ideas why this is happening.
Please help

[tbscope]

char *data;
socket->readLine(data,i);

Of course this crashes. What does data point to?