Function replace_user_table

sql/sql_acl.cc:4881–5133

static USER_AUTH auth_no_password;

static int replace_user_table(THD *thd, const User_table &user_table,
                              LEX_USER * const combo, privilege_t rights,
                              const bool revoke_grant,
                              const bool can_create_user,
                              const bool no_auto_create)
{
  int error = -1;
  uint nauth= 0;
  bool old_row_exists=0;
  uchar user_key[MAX_KEY_LENGTH];
  bool handle_as_role= combo->is_role();
  LEX *lex= thd->lex;
  TABLE *table= user_table.table();
  ACL_USER new_acl_user, *old_acl_user= 0;
  DBUG_ENTER("replace_user_table");

  mysql_mutex_assert_owner(&acl_cache->lock);

  table->use_all_columns();
  user_table.set_host(combo->host.str,combo->host.length);
  user_table.set_user(combo->user.str,combo->user.length);
  key_copy(user_key, table->record[0], table->key_info,
           table->key_info->key_length);

  if (table->file->ha_index_read_idx_map(table->record[0], 0, user_key,
                                         HA_WHOLE_KEY, HA_READ_KEY_EXACT))
  {
    if (revoke_grant)
    {
      if (combo->host.length)
        my_error(ER_NONEXISTING_GRANT, MYF(0), combo->user.str,
                 combo->host.str);
      else
        my_error(ER_INVALID_ROLE, MYF(0), combo->user.str);
      goto end;
    }
    /*
      There are four options which affect the process of creation of
      a new user (mysqld option --safe-create-user, 'insert' privilege
      on 'mysql.user' table, using 'GRANT' with 'IDENTIFIED BY' and
      SQL_MODE flag NO_AUTO_CREATE_USER). Below is the simplified rule
      how it should work.
      if (safe-user-create && ! INSERT_priv) => reject
      else if (identified_by) => create
      else if (no_auto_create_user) => reject
      else create

      see also test_if_create_new_users()
    */
    else if (!combo->has_auth() && no_auto_create)
    {
      my_error(ER_PASSWORD_NO_MATCH, MYF(0));
      goto end;
    }
    else if (!can_create_user)
    {
      my_error(ER_CANT_CREATE_USER_WITH_GRANT, MYF(0));
      goto end;