QFile: random access routines does not work properly, pos() always returns 0.

#include <QFile>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <share.h>
#include <io.h>
 
int main(int argc, char *argv[])
{
 QFile f("Test.txt");
 int nOpenMode = QIODevice::Truncate | QIODevice::ReadWrite | QIODevice::Unbuffered;
 int nOpenFlag = _O_CREAT | _O_TRUNC | _O_RDWR | _O_BINARY;

 int nFileDes = sopen("Test.txt", nOpenFlag, _SH_DENYRW, _S_IWRITE);
 if(nFileDes == -1)
 {
  return -1;
 }
 qDebug("Opened: %d", f.open(nFileDes, (QIODevice::OpenMode)nOpenMode));
 qDebug("Is Sequential: %d", f.isSequential());
 qDebug("Seek: %d", f.seek(5));
 qDebug("Wrote: %ld", f.write("111", strlen("111")));
 qDebug("Pos: %d", f.pos());
 f.close();
 return 0;
}