  _bdf_list_split( _bdf_list_t*   list,
                   char*          separators,
                   char*          line,
                   unsigned long  linelen )
  {
    int       mult, final_empty;
    char      *sp, *ep, *end;
    char      seps[32];
    FT_Error  error = BDF_Err_Ok;


    /* Initialize the list. */
    list->used = 0;
    if ( list->size )
    {
      list->field[0] = (char*)empty;
      list->field[1] = (char*)empty;
      list->field[2] = (char*)empty;
      list->field[3] = (char*)empty;
      list->field[4] = (char*)empty;
    }

    /* If the line is empty, then simply return. */
    if ( linelen == 0 || line[0] == 0 )
      goto Exit;

    /* In the original code, if the `separators' parameter is NULL or */
    /* empty, the list is split into individual bytes.  We don't need */
    /* this, so an error is signaled.                                 */
    if ( separators == 0 || *separators == 0 )
    {
      error = BDF_Err_Invalid_Argument;
      goto Exit;
    }

    /* Prepare the separator bitmap. */
    FT_MEM_ZERO( seps, 32 );

    /* If the very last character of the separator string is a plus, then */
    /* set the `mult' flag to indicate that multiple separators should be */
    /* collapsed into one.                                                */
    for ( mult = 0, sp = separators; sp && *sp; sp++ )
    {
      if ( *sp == '+' && *( sp + 1 ) == 0 )
        mult = 1;
      else
        setsbit( seps, *sp );
    }

    /* Break the line up into fields. */
    for ( final_empty = 0, sp = ep = line, end = sp + linelen;
          sp < end && *sp; )
    {
      /* Collect everything that is not a separator. */
      for ( ; *ep && !sbitset( seps, *ep ); ep++ )
        ;

      /* Resize the list if necessary. */
      if ( list->used == list->size )
      {
        error = _bdf_list_ensure( list, list->used + 1 );
        if ( error )
          goto Exit;
      }

      /* Assign the field appropriately. */
      list->field[list->used++] = ( ep > sp ) ? sp : (char*)empty;

      sp = ep;

      if ( mult )
      {
        /* If multiple separators should be collapsed, do it now by */
        /* setting all the separator characters to 0.               */
        for ( ; *ep && sbitset( seps, *ep ); ep++ )
          *ep = 0;
      }
      else if ( *ep != 0 )
        /* Don't collapse multiple separators by making them 0, so just */
        /* make the one encountered 0.                                  */
        *ep++ = 0;

      final_empty = ( ep > sp && *ep == 0 );
      sp = ep;
    }

    /* Finally, NULL-terminate the list. */
    if ( list->used + final_empty >= list->size )
    {
      error = _bdf_list_ensure( list, list->used + final_empty + 1 );
      if ( error )
        goto Exit;
    }

    if ( final_empty )
      list->field[list->used++] = (char*)empty;

    list->field[list->used] = 0;

  Exit:
    return error;
  }

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.