int64 Archive::Tell()
{
#ifdef USE_QOPEN
  int64 QPos;
  if (QOpen.Tell(&QPos))
    return QPos;
#endif
#ifdef USE_ARCMEM
  int64 APos;
  if (ArcMem.Tell(&APos))
    return APos;
#endif
  return File::Tell();
}
The software writes data past the end, or before the beginning, of the intended buffer.