QFile::writeBlock: File not open

[safknw]

I made a dialog which takes, which two files as argument first one is source file nad second is destination file to copy first file.

void mainForm::copy()
{
    QFile src1 (le_src->text() );
    QFile dest (le_dest->text() );
    if(!src1.open(IO_ReadOnly) || !dest.open(IO_WriteOnly)) 
	return;
    else
	qDebug("Files opened.");
 
    int len = src1.size()/1024;
    progress->setTotalSteps(len);
    progress->show();
    char *ch;
    while(!src.atEnd())
    {
	//ch = src.getch();
	src1.readBlock(ch, Q_ULONG(1042));
	//dest.putch(ch);
	dest.writeBlock (ch, Q_ULONG(1042));
	progress->setProgress(progress->progress()+1);
	//qApp->processEvents();
    } 
}

void mainForm::copy()
{
    QFile src1 (le_src->text() );
    QFile dest (le_dest->text() );
    if(!src1.open(IO_ReadOnly) || !dest.open(IO_WriteOnly)) 
	return;
    else
	qDebug("Files opened.");
    
    int len = src1.size()/1024;
    progress->setTotalSteps(len);
    progress->show();
    char *ch;
    while(!src.atEnd())
    {
	//ch = src.getch();
	src1.readBlock(ch, Q_ULONG(1042));
	//dest.putch(ch);
	dest.writeBlock (ch, Q_ULONG(1042));
	progress->setProgress(progress->progress()+1);
	//qApp->processEvents();
    } 
}

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When I run this code following out put shows
Files opened.
QFile::writeBlock: File not open
Segmentation fault

I didn't understand what is wrong with this code.

[jacek]

You don't create a buffer for data and pass uninitialized pointer to readBlock() and writeBlock().