Method prepare_handle_duplicate

sql/sql_insert.cc:2453–2511

int Write_record::prepare_handle_duplicate(int error)
{
  /*
    If we do more than one iteration of the replace loop, from the second one the
    row will have an explicit value in the autoinc field, which was set at
    the first call of handler::update_auto_increment(). So we must save
    the autogenerated value to avoid thd->insert_id_for_cur_row to become
    0.
  */
  if (table->file->insert_id_for_cur_row > 0)
    insert_id_for_cur_row= table->file->insert_id_for_cur_row;
  else
    table->file->insert_id_for_cur_row= insert_id_for_cur_row;

  if (is_fatal_error(error))
    return on_ha_error(error);

  bool is_duplicate_key_error=
          table->file->is_fatal_error(error, HA_CHECK_ALL & ~HA_CHECK_DUP);
  if (!is_duplicate_key_error)
  {
    /*
      We come here when we had an ignorable error which is not a duplicate
      key error. In this we ignore error if ignore flag is set, otherwise
      report error as usual. We will not do any duplicate key processing.
    */
    if (info->ignore)
    {
      table->file->print_error(error, MYF(ME_WARNING));
      ignored_error= true;
      return 1; /* Ignoring a not fatal error */
    }
    return on_ha_error(error);
  }

  key_nr = table->file->get_dup_key(error);

  if (unlikely(key_nr == std::numeric_limits<decltype(key_nr)>::max()))
    return on_ha_error(HA_ERR_FOUND_DUPP_KEY); /* Database can't find key */

  DEBUG_SYNC(thd, "write_row_replace");

  /* Read all columns for the row we are going to replace */
  table->use_all_columns();
  /*
    Don't allow REPLACE to replace a row when an auto_increment column
    was used.  This ensures that we don't get a problem when the
    whole range of the key has been used.
  */
  if (info->handle_duplicates == DUP_REPLACE && table->next_number_field &&
      key_nr == table->s->next_number_index && insert_id_for_cur_row > 0)
    return on_ha_error(error);

  error= locate_dup_record();
  if (error)
    return on_ha_error(error);

  return 0;