Re: [Quickfix-developers] Field with embedded null character

[Caleb E. <cal...@gm...>]

On Thu, 28 Oct 2004 09:05:47 -0400, Caleb Epstein
<cal...@gm...> wrote:

> That said, it does seem that QuickFIX has a bug in the message
> serialization code when dealing with fields having embedded \0 bytes:

Ironically, the bug turns out to be in code that I submitted.  In
Field.h there is this optimization:

    char buf[64];

    if( 13 + m_string.length() < sizeof(buf) )
    {
      m_length = sprintf( buf, "%d=%*.*s\001", m_field,
                          (int)m_string.length(), (int)m_string.length(),
                          m_string.data() );
      m_data.assign( buf, m_length );
    }

At least on Linux, sprintf refuses to write anything after a \0 byte
to the output buffer, so the field gets padded with spaces on the
left.  Here's a re-worked version that is not as simple but is still
faster than the string + string + ... implementation that is used when
the value is too long to fit in buf:

    char buf[64];

    if( 13 + m_string.length() < sizeof(buf) )
    {
      int fidlen = sprintf (buf, "%d=", m_field);
      m_length = fidlen + m_string.length() + 1;
      memcpy (buf + fidlen, m_string.data(), m_string.length());
      buf[m_length - 1] = '\001';
      m_data.assign (buf, m_length);
    }

-- 
Caleb Epstein
cal...@gm...