Function acl_setauthorization

sql/sql_acl.cc:12749–12828

int acl_setauthorization(THD *thd, const LEX_USER *user)
{
  if (!initialized)
  {
    my_error(ER_OPTION_PREVENTS_STATEMENT, MYF(0), "--skip-grant-tables");
    return 1;
  }

  Security_context *sctx= thd->security_ctx, save_security_ctx= *sctx;

  DBUG_ASSERT(*user->host.str); // guaranteed by the parser

  if (user->host.str == host_not_specified.str)
  {
    my_error(ER_NO_SUCH_USER, MYF(0), user->user.str, "");
    return 1;
  }

  if (!user->user.length)
  {
    my_error(ER_NO_SUCH_USER, MYF(0), "", user->host.str);
    return 1;
  }

  mysql_mutex_lock(&acl_cache->lock);
  ACL_USER *acl_user= find_user_or_anon(user->host.str, user->user.str, user->host.str);
  if (acl_user)
    acl_user= acl_user->copy(thd->mem_root);
  mysql_mutex_unlock(&acl_cache->lock);

  if (!acl_user)
  {
    if (!(sctx->master_access & PRIV_SUDO_CHANGE_USER))
      goto access_denied;
    my_error(ER_NO_SUCH_USER, MYF(0), user->user.str, user->host.str);
    return 1;
  }

  if (!(sctx->master_access & PRIV_SUDO_CHANGE_USER) &&
      (strcmp(user->user.str, sctx->user) ||
       strcmp(user->host.str, sctx->host_or_ip) ||
       strcmp(acl_user->user.str, sctx->priv_user) ||
       strcmp(acl_user->host.hostname, sctx->priv_host)))
    goto access_denied;

  thd->change_user();
  thd->clear_error();                         // if errors from rollback
  my_free(const_cast<char*>(thd->db.str));
  thd->reset_db(&null_clex_str);

  sctx->init();
  sctx->user= *user->user.str
              ? my_strndup(key_memory_MPVIO_EXT_auth_info, user->user.str,
                           user->user.length, MYF(MY_WME))
              : NULL;
  if (strcmp(user->host.str, my_localhost) == 0)
    sctx->host= my_localhost;
  else