Function send_format_descriptor_event

sql/sql_repl.cc:2773–3008

* send format descriptor event for one binlog file */

 * send format descriptor event for one binlog file
 */
static int send_format_descriptor_event(binlog_send_info *info, IO_CACHE *log,
                                        LOG_INFO *linfo, my_off_t start_pos)
{
  int error;
  ulong ev_offset;
  THD *thd= info->thd;
  String *packet= info->packet;
  Log_event_type event_type;
  bool initial_log_pos= info->clear_initial_log_pos;
  DBUG_ENTER("send_format_descriptor_event");

  /**
   * 1) reset fdev before each log-file
   * 2) read first event, should be the format descriptor
   * 3) read second event, *might* be start encryption event
   *    if it's isn't, seek back to undo this read
   */
  if (info->fdev != NULL)
    delete info->fdev;

  if (!(info->fdev= new Format_description_log_event(4)))
  {
    info->errmsg= "Out of memory initializing format_description event";
    info->error= ER_MASTER_FATAL_ERROR_READING_BINLOG;
    DBUG_RETURN(1);
  }

  /* reset transmit packet for the event read from binary log file */
  if (reset_transmit_packet(info, info->flags, &ev_offset, &info->errmsg))
    DBUG_RETURN(1);

  /*
    Try to find a Format_description_log_event at the beginning of
    the binlog
  */
  info->last_pos= my_b_tell(log);
  error= Log_event::read_log_event(log, packet, info->fdev,
                                   opt_master_verify_checksum
                                   ? info->current_checksum_alg
                                   : BINLOG_CHECKSUM_ALG_OFF);
  linfo->pos= my_b_tell(log);

  if (unlikely(error))
  {
    set_read_error(info, error);
    DBUG_RETURN(1);
  }

  event_type= static_cast<Log_event_type>(
    static_cast<unsigned char>((*packet)[ev_offset + EVENT_TYPE_OFFSET])
  );

  /*
    The packet has offsets equal to the normal offsets in a
    binlog event + ev_offset (the first ev_offset characters are
    the header (default \0)).
  */
  DBUG_PRINT("info",