bool DML_prelocking_strategy::
handle_view(THD *thd, Query_tables_list *prelocking_ctx,
            TABLE_LIST *table_list, bool *need_prelocking)
{
  if (table_list->view->uses_stored_routines())
  {
    *need_prelocking= TRUE;

    sp_update_stmt_used_routines(thd, prelocking_ctx,
                                 &table_list->view->sroutines_list,
                                 table_list->top_table());
  }

  /*
    If a trigger was defined on one of the associated tables then assign the
    'trg_event_map' value of the view to the next table in table_list. When a
    Stored function is invoked, all the associated tables including the tables
    associated with the trigger are prelocked.
  */
  if (table_list->trg_event_map && table_list->next_global)
    table_list->next_global->trg_event_map= table_list->trg_event_map;
  return FALSE;
}


MDEV-25766 Unused CTE lead to a crash in find_field_in_tables/find_order_in_list

Do not assume that subquery Item always present.

unique_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list,
             uint check_flag)
{
  TABLE_LIST *dup;

  table= table->find_table_for_update();

  if (table->table && table->table->file->ht->db_type == DB_TYPE_MRG_MYISAM)
  {
    TABLE_LIST *child;
    dup= NULL;
    /* Check duplicates of all merge children. */
    for (child= table->next_global; child && child->parent_l == table;
         child= child->next_global)
    {
      if ((dup= find_dup_table(thd, child, child->next_global, check_flag)))
        break;
    }
  }
  else
    dup= find_dup_table(thd, table, table_list, check_flag);
  return dup;
}

MariaDB through 10.5.9 allows an application crash in find_field_in_tables and find_order_in_list via an unused common table expression (CTE).


  virtual bool handle_condition(THD *thd,
                                  uint sql_errno,
                                  const char* sqlstate,
                                  Sql_condition::enum_warning_level *level,
                                  const char* msg,
                                  Sql_condition ** cond_hdl)
  {
    if (sql_errno == ER_LOCK_DEADLOCK)
    {
      thd->mark_transaction_to_rollback(true);
    }
    /*
      We have marked this transaction to rollback. Return false to allow
      error to be reported or handled by other handlers.
    */
    return false;
  }


find_field_in_tables(THD *thd, Item_ident *item,
                     TABLE_LIST *first_table, TABLE_LIST *last_table,
		     Item **ref, find_item_error_report_type report_error,
                     bool check_privileges, bool register_tree_change)
{
  Field *found=0;
  const char *db= item->db_name;
  const char *table_name= item->table_name;
  const char *name= item->field_name;
  uint length=(uint) strlen(name);
  char name_buff[SAFE_NAME_LEN+1];
  TABLE_LIST *cur_table= first_table;
  TABLE_LIST *actual_table;
  bool allow_rowid;

  if (!table_name || !table_name[0])
  {
    table_name= 0;                              // For easier test
    db= 0;
  }

  allow_rowid= table_name || (cur_table && !cur_table->next_local);

  if (item->cached_table)
  {
    DBUG_PRINT("info", ("using cached table"));
    /*
      This shortcut is used by prepared statements. We assume that
      TABLE_LIST *first_table is not changed during query execution (which
      is true for all queries except RENAME but luckily RENAME doesn't
      use fields...) so we can rely on reusing pointer to its member.
      With this optimization we also miss case when addition of one more
      field makes some prepared query ambiguous and so erroneous, but we
      accept this trade off.
    */
    TABLE_LIST *table_ref= item->cached_table;
    /*
      The condition (table_ref->view == NULL) ensures that we will call
      find_field_in_table even in the case of information schema tables
      when table_ref->field_translation != NULL.
      */
    if (table_ref->table && !table_ref->view &&
        (!table_ref->is_merged_derived() ||
         (!table_ref->is_multitable() && table_ref->merged_for_insert)))
    {

      found= find_field_in_table(thd, table_ref->table, name, length,
                                 TRUE, &(item->cached_field_index));
#ifndef NO_EMBEDDED_ACCESS_CHECKS
      /* Check if there are sufficient access rights to the found field. */
      if (found && check_privileges && !is_temporary_table(table_ref) &&
          check_column_grant_in_table_ref(thd, table_ref, name, length))
        found= WRONG_GRANT;
#endif
    }
    else
      found= find_field_in_table_ref(thd, table_ref, name, length, item->name,
                                     NULL, NULL, ref, check_privileges,
                                     TRUE, &(item->cached_field_index),
                                     register_tree_change,
                                     &actual_table);
    if (found)
    {
      if (found == WRONG_GRANT)
	return (Field*) 0;

      /*
        Only views fields should be marked as dependent, not an underlying
        fields.
      */
      if (!table_ref->belong_to_view &&
          !table_ref->belong_to_derived)
      {
        SELECT_LEX *current_sel= item->context->select_lex;
        SELECT_LEX *last_select= table_ref->select_lex;
        bool all_merged= TRUE;
        for (SELECT_LEX *sl= current_sel; sl && sl!=last_select;
             sl=sl->outer_select())
        {
          Item *subs= sl->master_unit()->item;
          if (!subs ||
              (subs->type() == Item::SUBSELECT_ITEM &&
               ((Item_subselect*)subs)->substype() == Item_subselect::IN_SUBS &&
               ((Item_in_subselect*)subs)->test_strategy(SUBS_SEMI_JOIN)))
          {
            continue;
          }
          all_merged= FALSE;
          break;
        }
        /*
          If the field was an outer referencee, mark all selects using this
          sub query as dependent on the outer query
        */
        if (!all_merged && current_sel != last_select)
        {
          mark_select_range_as_dependent(thd, last_select, current_sel,
                                         found, *ref, item, true);
        }
      }
      return found;
    }
  }
  else
    item->can_be_depended= TRUE;

  if (db && lower_case_table_names)
  {
    /*
      convert database to lower case for comparison.
      We can't do this in Item_field as this would change the
      'name' of the item which may be used in the select list
    */
    strmake_buf(name_buff, db);
    my_casedn_str(files_charset_info, name_buff);
    db= name_buff;
  }

  if (last_table)
    last_table= last_table->next_name_resolution_table;

  for (; cur_table != last_table ;
       cur_table= cur_table->next_name_resolution_table)
  {
    Field *cur_field= find_field_in_table_ref(thd, cur_table, name, length,
                                              item->name, db, table_name, ref,
                                              (thd->lex->sql_command ==
                                               SQLCOM_SHOW_FIELDS)
                                              ? false : check_privileges,
                                              allow_rowid,
                                              &(item->cached_field_index),
                                              register_tree_change,
                                              &actual_table);
    if (cur_field)
    {
      if (cur_field == WRONG_GRANT)
      {
        if (thd->lex->sql_command != SQLCOM_SHOW_FIELDS)
          return (Field*) 0;

        thd->clear_error();
        cur_field= find_field_in_table_ref(thd, cur_table, name, length,
                                           item->name, db, table_name, ref,
                                           false,
                                           allow_rowid,
                                           &(item->cached_field_index),
                                           register_tree_change,
                                           &actual_table);
        if (cur_field)
        {
          Field *nf=new Field_null(NULL,0,Field::NONE,
                                   cur_field->field_name,
                                   &my_charset_bin);
          nf->init(cur_table->table);
          cur_field= nf;
        }
      }

      /*
        Store the original table of the field, which may be different from
        cur_table in the case of NATURAL/USING join.
      */
      item->cached_table= (!actual_table->cacheable_table || found) ?
                          0 : actual_table;

      DBUG_ASSERT(thd->where);
      /*
        If we found a fully qualified field we return it directly as it can't
        have duplicates.
       */
      if (db)
        return cur_field;

      if (found)
      {
        if (report_error == REPORT_ALL_ERRORS ||
            report_error == IGNORE_EXCEPT_NON_UNIQUE)
          my_error(ER_NON_UNIQ_ERROR, MYF(0),
                   table_name ? item->full_name() : name, thd->where);
        return (Field*) 0;
      }
      found= cur_field;
    }
  }

  if (found)
    return found;

  /*
    If the field was qualified and there were no tables to search, issue
    an error that an unknown table was given. The situation is detected
    as follows: if there were no tables we wouldn't go through the loop
    and cur_table wouldn't be updated by the loop increment part, so it
    will be equal to the first table.
  */
  if (table_name && (cur_table == first_table) &&
      (report_error == REPORT_ALL_ERRORS ||
       report_error == REPORT_EXCEPT_NON_UNIQUE))
  {
    char buff[SAFE_NAME_LEN*2 + 2];
    if (db && db[0])
    {
      strxnmov(buff,sizeof(buff)-1,db,".",table_name,NullS);
      table_name=buff;
    }
    my_error(ER_UNKNOWN_TABLE, MYF(0), table_name, thd->where);
  }
  else
  {
    if (report_error == REPORT_ALL_ERRORS ||
        report_error == REPORT_EXCEPT_NON_UNIQUE)
      my_error(ER_BAD_FIELD_ERROR, MYF(0), item->full_name(), thd->where);
    else
      found= not_found_field;
  }
  return found;
}


bool tdc_open_view(THD *thd, TABLE_LIST *table_list, uint flags)
{
  TABLE not_used;
  TABLE_SHARE *share;
  bool err= TRUE;

  if (!(share= tdc_acquire_share(thd, table_list, GTS_VIEW)))
    return TRUE;

  DBUG_ASSERT(share->is_view);

  if (flags & CHECK_METADATA_VERSION)
  {
    /*
      Check TABLE_SHARE-version of view only if we have been instructed to do
      so. We do not need to check the version if we're executing CREATE VIEW or
      ALTER VIEW statements.

      In the future, this functionality should be moved out from
      tdc_open_view(), and  tdc_open_view() should became a part of a clean
      table-definition-cache interface.
    */
    if (check_and_update_table_version(thd, table_list, share))
      goto ret;
  }

  err= mysql_make_view(thd, share, table_list, (flags & OPEN_VIEW_NO_PARSE));
ret:
  tdc_release_share(share);

  return err;
}


find_field_in_table(THD *thd, TABLE *table, const char *name, uint length,
                    bool allow_rowid, uint *cached_field_index_ptr)
{
  Field **field_ptr, *field;
  uint cached_field_index= *cached_field_index_ptr;
  DBUG_ENTER("find_field_in_table");
  DBUG_PRINT("enter", ("table: '%s', field name: '%s'", table->alias.c_ptr(),
                       name));

  /* We assume here that table->field < NO_CACHED_FIELD_INDEX = UINT_MAX */
  if (cached_field_index < table->s->fields &&
      !my_strcasecmp(system_charset_info,
                     table->field[cached_field_index]->field_name, name))
    field_ptr= table->field + cached_field_index;
  else if (table->s->name_hash.records)
  {
    field_ptr= (Field**) my_hash_search(&table->s->name_hash, (uchar*) name,
                                        length);
    if (field_ptr)
    {
      /*
        field_ptr points to field in TABLE_SHARE. Convert it to the matching
        field in table
      */
      field_ptr= (table->field + (field_ptr - table->s->field));
    }
  }
  else
  {
    if (!(field_ptr= table->field))
      DBUG_RETURN((Field *)0);
    for (; *field_ptr; ++field_ptr)
      if (!my_strcasecmp(system_charset_info, (*field_ptr)->field_name, name))
        break;
  }

  if (field_ptr && *field_ptr)
  {
    *cached_field_index_ptr= (uint)(field_ptr - table->field);
    field= *field_ptr;
  }
  else
  {
    if (!allow_rowid ||
        my_strcasecmp(system_charset_info, name, "_rowid") ||
        table->s->rowid_field_offset == 0)
      DBUG_RETURN((Field*) 0);
    field= table->field[table->s->rowid_field_offset-1];
  }

  update_field_dependencies(thd, field, table);

  DBUG_RETURN(field);
}


  MDL_deadlock_handler(Open_table_context *ot_ctx_arg)
    : m_ot_ctx(ot_ctx_arg), m_is_active(FALSE)
  {}


bool Alter_table_prelocking_strategy::
handle_routine(THD *thd, Query_tables_list *prelocking_ctx,
               Sroutine_hash_entry *rt, sp_head *sp, bool *need_prelocking)
{
  return FALSE;
}


void setup_defaults(THD *thd, List<Item> &fields, List<Item> &values)
{
  List_iterator<Item> fit(fields);
  List_iterator<Item> vit(values);

  for (Item *value= vit++, *f_item= fit++; value; value= vit++, f_item= fit++)
  {
    value->walk(&Item::enchant_default_with_arg_processor, false, f_item);
  }
}


check_and_update_table_version(THD *thd,
                               TABLE_LIST *tables, TABLE_SHARE *table_share)
{
  if (! tables->is_table_ref_id_equal(table_share))
  {
    if (thd->m_reprepare_observer &&
        thd->m_reprepare_observer->report_error(thd))
    {
      /*
        Version of the table share is different from the
        previous execution of the prepared statement, and it is
        unacceptable for this SQLCOM. Error has been reported.
      */
      DBUG_ASSERT(thd->is_error());
      return TRUE;
    }
    /* Always maintain the latest version and type */
    tables->set_table_ref_id(table_share);
  }

  DBUG_EXECUTE_IF("reprepare_each_statement", return inject_reprepare(thd););
  return FALSE;
}


void Locked_tables_list::
unlink_all_closed_tables(THD *thd, MYSQL_LOCK *lock, size_t reopen_count)
{
  /* If we managed to take a lock, unlock tables and free the lock. */
  if (lock)
    mysql_unlock_tables(thd, lock);
  /*
    If a failure happened in reopen_tables(), we may have succeeded
    reopening some tables, but not all.
    This works when the connection was killed in mysql_lock_tables().
  */
  if (reopen_count)
  {
    while (reopen_count--)
    {
      /*
        When closing the table, we must remove it
        from thd->open_tables list.
        We rely on the fact that open_table() that was used
        in reopen_tables() always links the opened table
        to the beginning of the open_tables list.
      */
      DBUG_ASSERT(thd->open_tables == m_reopen_array[reopen_count]->table);

      thd->open_tables->pos_in_locked_tables->table= NULL;
      thd->open_tables->pos_in_locked_tables= 0;

      close_thread_table(thd, &thd->open_tables);
    }
  }
  /* Exclude all closed tables from the LOCK TABLES list. */
  for (TABLE_LIST *table_list= m_locked_tables; table_list; table_list=
       table_list->next_global)
  {
    if (table_list->table == NULL)
    {
      /* Unlink from list. */
      *table_list->prev_global= table_list->next_global;
      if (table_list->next_global == NULL)
        m_locked_tables_last= table_list->prev_global;
      else
        table_list->next_global->prev_global= table_list->prev_global;
      m_locked_tables_count--;
    }
  }

  /* If no tables left, do an automatic UNLOCK TABLES */
  if (thd->lock && thd->lock->table_count == 0)
    unlock_locked_tables(thd);
}


find_field_in_natural_join(THD *thd, TABLE_LIST *table_ref, const char *name,
                           uint length, Item **ref, bool register_tree_change,
                           TABLE_LIST **actual_table)
{
  List_iterator_fast<Natural_join_column>
    field_it(*(table_ref->join_columns));
  Natural_join_column *nj_col, *curr_nj_col;
  Field *UNINIT_VAR(found_field);
  Query_arena *UNINIT_VAR(arena), backup;
  DBUG_ENTER("find_field_in_natural_join");
  DBUG_PRINT("enter", ("field name: '%s', ref %p",
		       name, ref));
  DBUG_ASSERT(table_ref->is_natural_join && table_ref->join_columns);
  DBUG_ASSERT(*actual_table == NULL);

  for (nj_col= NULL, curr_nj_col= field_it++; curr_nj_col;
       curr_nj_col= field_it++)
  {
    if (!my_strcasecmp(system_charset_info, curr_nj_col->name(), name))
    {
      if (nj_col)
      {
        my_error(ER_NON_UNIQ_ERROR, MYF(0), name, thd->where);
        DBUG_RETURN(NULL);
      }
      nj_col= curr_nj_col;
    }
  }
  if (!nj_col)
    DBUG_RETURN(NULL);

  if (nj_col->view_field)
  {
    Item *item;
    if (register_tree_change)
      arena= thd->activate_stmt_arena_if_needed(&backup);
    /*
      create_item() may, or may not create a new Item, depending on the
      column reference. See create_view_field() for details.
    */
    item= nj_col->create_item(thd);
    if (!item)
      DBUG_RETURN(NULL);

    /*
     *ref != NULL means that *ref contains the item that we need to
     replace. If the item was aliased by the user, set the alias to
     the replacing item.
     We need to set alias on both ref itself and on ref real item.
     */
    if (*ref && !(*ref)->is_autogenerated_name)
    {
      item->set_name(thd, (*ref)->name, (*ref)->name_length,
                     system_charset_info);
      item->real_item()->set_name(thd, (*ref)->name, (*ref)->name_length,
                                  system_charset_info);
    }
    if (register_tree_change && arena)
      thd->restore_active_arena(arena, &backup);

    if (!item)
      DBUG_RETURN(NULL);
    DBUG_ASSERT(nj_col->table_field == NULL);
    if (nj_col->table_ref->schema_table_reformed)
    {
      /*
        Translation table items are always Item_fields and fixed
        already('mysql_schema_table' function). So we can return
        ->field. It is used only for 'show & where' commands.
      */
      DBUG_RETURN(((Item_field*) (nj_col->view_field->item))->field);
    }
    if (register_tree_change)
      thd->change_item_tree(ref, item);
    else
      *ref= item;
    found_field= (Field*) view_ref_found;
  }
  else
  {
    /* This is a base table. */
    DBUG_ASSERT(nj_col->view_field == NULL);
    Item *ref= 0;
    /*
      This fix_fields is not necessary (initially this item is fixed by
      the Item_field constructor; after reopen_tables the Item_func_eq
      calls fix_fields on that item), it's just a check during table
      reopening for columns that was dropped by the concurrent connection.
    */
    if (!nj_col->table_field->fixed &&
        nj_col->table_field->fix_fields(thd, &ref))
    {
      DBUG_PRINT("info", ("column '%s' was dropped by the concurrent connection",
                          nj_col->table_field->name));
      DBUG_RETURN(NULL);
    }
    DBUG_ASSERT(ref == 0);                      // Should not have changed
    DBUG_ASSERT(nj_col->table_ref->table == nj_col->table_field->field->table);
    found_field= nj_col->table_field->field;
    update_field_dependencies(thd, found_field, nj_col->table_ref->table);
  }

  *actual_table= nj_col->table_ref;

  DBUG_RETURN(found_field);
}


bool close_cached_tables(THD *thd, TABLE_LIST *tables,
                         bool wait_for_refresh, ulong timeout)
{
  bool result= FALSE;
  struct timespec abstime;
  tdc_version_t refresh_version;
  DBUG_ENTER("close_cached_tables");
  DBUG_ASSERT(thd || (!wait_for_refresh && !tables));

  refresh_version= tdc_increment_refresh_version();

  if (!tables)
  {
    /*
      Force close of all open tables.

      Note that code in TABLE_SHARE::wait_for_old_version() assumes that
      incrementing of refresh_version is followed by purge of unused table
      shares.
    */
    kill_delayed_threads();
    /*
      Get rid of all unused TABLE and TABLE_SHARE instances. By doing
      this we automatically close all tables which were marked as "old".
    */
    tc_purge(true);
    /* Free table shares which were not freed implicitly by loop above. */
    tdc_purge(true);
  }
  else
  {
    bool found=0;
    for (TABLE_LIST *table= tables; table; table= table->next_local)
    {
      /* tdc_remove_table() also sets TABLE_SHARE::version to 0. */
      found|= tdc_remove_table(thd, TDC_RT_REMOVE_UNUSED, table->db,
                               table->table_name, TRUE);
    }
    if (!found)
      wait_for_refresh=0;			// Nothing to wait for
  }

  DBUG_PRINT("info", ("open table definitions: %d",
                      (int) tdc_records()));

  if (!wait_for_refresh)
    DBUG_RETURN(result);

  if (thd->locked_tables_mode)
  {
    /*
      If we are under LOCK TABLES, we need to reopen the tables without
      opening a door for any concurrent threads to sneak in and get
      lock on our tables. To achieve this we use exclusive metadata
      locks.
    */
    TABLE_LIST *tables_to_reopen= (tables ? tables :
                                  thd->locked_tables_list.locked_tables());

    /* Close open HANDLER instances to avoid self-deadlock. */
    mysql_ha_flush_tables(thd, tables_to_reopen);

    for (TABLE_LIST *table_list= tables_to_reopen; table_list;
         table_list= table_list->next_global)
    {
      int err;
      /* A check that the table was locked for write is done by the caller. */
      TABLE *table= find_table_for_mdl_upgrade(thd, table_list->db,
                                               table_list->table_name, &err);

      /* May return NULL if this table has already been closed via an alias. */
      if (! table)
        continue;

      if (wait_while_table_is_used(thd, table,
                                   HA_EXTRA_PREPARE_FOR_FORCED_CLOSE))
      {
        result= TRUE;
        goto err_with_reopen;
      }
      close_all_tables_for_name(thd, table->s, HA_EXTRA_NOT_USED, NULL);
    }
  }

  /* Wait until all threads have closed all the tables we are flushing. */
  DBUG_PRINT("info", ("Waiting for other threads to close their open tables"));

  /*
    To a self-deadlock or deadlocks with other FLUSH threads
    waiting on our open HANDLERs, we have to flush them.
  */
  mysql_ha_flush(thd);
  DEBUG_SYNC(thd, "after_flush_unlock");

  if (!tables)
  {
    int r= 0;
    close_cached_tables_arg argument;
    argument.refresh_version= refresh_version;
    set_timespec(abstime, timeout);

    while (!thd->killed &&
           (r= tdc_iterate(thd,
                           (my_hash_walk_action) close_cached_tables_callback,
                           &argument)) == 1 &&
           !argument.element->share->wait_for_old_version(thd, &abstime,
                                    MDL_wait_for_subgraph::DEADLOCK_WEIGHT_DDL))
      /* no-op */;

    if (r)
      result= TRUE;
  }
  else
  {
    for (TABLE_LIST *table= tables; table; table= table->next_local)
    {
      if (thd->killed)
        break;
      if (tdc_wait_for_old_version(thd, table->db, table->table_name, timeout,
                                   MDL_wait_for_subgraph::DEADLOCK_WEIGHT_DDL,
                                   refresh_version))
      {
        result= TRUE;
        break;
      }
    }
  }

err_with_reopen:
  if (thd->locked_tables_mode)
  {
    /*
      No other thread has the locked tables open; reopen them and get the
      old locks. This should always succeed (unless some external process
      has removed the tables)
    */
    if (thd->locked_tables_list.reopen_tables(thd, false))
      result= true;
    /*
      Since downgrade_lock() won't do anything with shared
      metadata lock it is much simpler to go through all open tables rather
      than picking only those tables that were flushed.
    */
    for (TABLE *tab= thd->open_tables; tab; tab= tab->next)
      tab->mdl_ticket->downgrade_lock(MDL_SHARED_NO_READ_WRITE);
  }
  DBUG_RETURN(result);
}


int setup_conds(THD *thd, TABLE_LIST *tables, List<TABLE_LIST> &leaves,
                COND **conds)
{
  SELECT_LEX *select_lex= thd->lex->current_select;
  TABLE_LIST *table= NULL;	// For HP compilers
  /*
    it_is_update set to TRUE when tables of primary SELECT_LEX (SELECT_LEX
    which belong to LEX, i.e. most up SELECT) will be updated by
    INSERT/UPDATE/LOAD
    NOTE: using this condition helps to prevent call of prepare_check_option()
    from subquery of VIEW, because tables of subquery belongs to VIEW
    (see condition before prepare_check_option() call)
  */
  bool it_is_update= (select_lex == &thd->lex->select_lex) &&
    thd->lex->which_check_option_applicable();
  bool save_is_item_list_lookup= select_lex->is_item_list_lookup;
  TABLE_LIST *derived= select_lex->master_unit()->derived;
  DBUG_ENTER("setup_conds");

  /* Do not fix conditions for the derived tables that have been merged */
  if (derived && derived->merged)
    DBUG_RETURN(0);

  select_lex->is_item_list_lookup= 0;

  thd->mark_used_columns= MARK_COLUMNS_READ;
  DBUG_PRINT("info", ("thd->mark_used_columns: %d", thd->mark_used_columns));
  select_lex->cond_count= 0;
  select_lex->between_count= 0;
  select_lex->max_equal_elems= 0;

  for (table= tables; table; table= table->next_local)
  {
    if (select_lex == &thd->lex->select_lex &&
        select_lex->first_cond_optimization &&
        table->merged_for_insert &&
        table->prepare_where(thd, conds, FALSE))
      goto err_no_arena;
  }

  if (*conds)
  {
    thd->where="where clause";
    DBUG_EXECUTE("where",
                 print_where(*conds,
                             "WHERE in setup_conds",
                             QT_ORDINARY););
    /*
      Wrap alone field in WHERE clause in case it will be outer field of subquery
      which need persistent pointer on it, but conds could be changed by optimizer
    */
    if ((*conds)->type() == Item::FIELD_ITEM && !derived)
      wrap_ident(thd, conds);
    (*conds)->mark_as_condition_AND_part(NO_JOIN_NEST);
    if ((!(*conds)->fixed && (*conds)->fix_fields(thd, conds)) ||
	(*conds)->check_cols(1))
      goto err_no_arena;
  }

  /*
    Apply fix_fields() to all ON clauses at all levels of nesting,
    including the ones inside view definitions.
  */
  if (setup_on_expr(thd, tables, it_is_update))
    goto err_no_arena;

  if (!thd->stmt_arena->is_conventional())
  {
    /*
      We are in prepared statement preparation code => we should store
      WHERE clause changing for next executions.

      We do this ON -> WHERE transformation only once per PS/SP statement.
    */
    select_lex->where= *conds;
  }
  thd->lex->current_select->is_item_list_lookup= save_is_item_list_lookup;
  DBUG_RETURN(MY_TEST(thd->is_error()));

err_no_arena:
  select_lex->is_item_list_lookup= save_is_item_list_lookup;
  DBUG_RETURN(1);
}


bool restart_trans_for_tables(THD *thd, TABLE_LIST *table)
{
  DBUG_ENTER("restart_trans_for_tables");

  for (; table; table= table->next_global)
  {
    if (table->placeholder())
      continue;

    if (check_lock_and_start_stmt(thd, thd->lex, table))
    {
      DBUG_ASSERT(0);                           // Should never happen
      DBUG_RETURN(TRUE);
    }
  }
  DBUG_RETURN(FALSE);
}


Open_table_context::Open_table_context(THD *thd, uint flags)
  :m_thd(thd),
   m_failed_table(NULL),
   m_start_of_statement_svp(thd->mdl_context.mdl_savepoint()),
   m_timeout(flags & MYSQL_LOCK_IGNORE_TIMEOUT ?
             LONG_TIMEOUT : thd->variables.lock_wait_timeout),
   m_flags(flags),
   m_action(OT_NO_ACTION),
   m_has_locks(thd->mdl_context.has_locks()),
   m_has_protection_against_grl(FALSE)
{}


static void mark_used_tables_as_free_for_reuse(THD *thd, TABLE *table)
{
  for (; table ; table= table->next)
  {
    DBUG_ASSERT(table->pos_in_locked_tables == NULL ||
                table->pos_in_locked_tables->table == table);
    if (table->query_id == thd->query_id)
    {
      table->query_id= 0;
      table->file->ha_reset();
    }
    else if (table->file->check_table_binlog_row_based_done)
      table->file->clear_cached_table_binlog_row_based_flag();
  }
}


static void update_field_dependencies(THD *thd, Field *field, TABLE *table)
{
  DBUG_ENTER("update_field_dependencies");
  if (thd->mark_used_columns != MARK_COLUMNS_NONE)
  {
    MY_BITMAP *bitmap;

    /*
      We always want to register the used keys, as the column bitmap may have
      been set for all fields (for example for view).
    */

    table->covering_keys.intersect(field->part_of_key);

    if (field->vcol_info)
      table->mark_virtual_col(field);

    if (thd->mark_used_columns == MARK_COLUMNS_READ)
      bitmap= table->read_set;
    else
      bitmap= table->write_set;

    /*
       The test-and-set mechanism in the bitmap is not reliable during
       multi-UPDATE statements under MARK_COLUMNS_READ mode
       (thd->mark_used_columns == MARK_COLUMNS_READ), as this bitmap contains
       only those columns that are used in the SET clause. I.e they are being
       set here. See multi_update::prepare()
    */
    if (bitmap_fast_test_and_set(bitmap, field->field_index))
    {
      if (thd->mark_used_columns == MARK_COLUMNS_WRITE)
      {
        DBUG_PRINT("warning", ("Found duplicated field"));
        thd->dup_field= field;
      }
      else
      {
        DBUG_PRINT("note", ("Field found before"));
      }
      DBUG_VOID_RETURN;
    }
    if (table->get_fields_in_item_tree)
      field->flags|= GET_FIXED_FIELDS_FLAG;
    table->used_fields++;
  }
  else if (table->get_fields_in_item_tree)
    field->flags|= GET_FIXED_FIELDS_FLAG;
  DBUG_VOID_RETURN;
}


Locked_tables_list::unlock_locked_tables(THD *thd)
{
  DBUG_ASSERT(!thd->in_sub_stmt &&
              !(thd->state_flags & Open_tables_state::BACKUPS_AVAIL));
  /*
    Sic: we must be careful to not close open tables if
    we're not in LOCK TABLES mode: unlock_locked_tables() is
    sometimes called implicitly, expecting no effect on
    open tables, e.g. from begin_trans().
  */
  if (thd->locked_tables_mode != LTM_LOCK_TABLES)
    return;

  for (TABLE_LIST *table_list= m_locked_tables;
       table_list; table_list= table_list->next_global)
  {
    /*
      Clear the position in the list, the TABLE object will be
      returned to the table cache.
    */
    if (table_list->table)                    // If not closed
      table_list->table->pos_in_locked_tables= NULL;
  }
  thd->leave_locked_tables_mode();

  TRANSACT_TRACKER(clear_trx_state(thd, TX_LOCKED_TABLES));

  DBUG_ASSERT(thd->transaction.stmt.is_empty());
  close_thread_tables(thd);

  /*
    We rely on the caller to implicitly commit the
    transaction and release transactional locks.
  */

  /*
    After closing tables we can free memory used for storing lock
    request for metadata locks and TABLE_LIST elements.
  */
  reset();
}


prepare_fk_prelocking_list(THD *thd, Query_tables_list *prelocking_ctx,
                           TABLE_LIST *table_list, bool *need_prelocking,
                           uint8 op)
{
  List <FOREIGN_KEY_INFO> fk_list;
  List_iterator<FOREIGN_KEY_INFO> fk_list_it(fk_list);
  FOREIGN_KEY_INFO *fk;
  Query_arena *arena, backup;

  arena= thd->activate_stmt_arena_if_needed(&backup);

  table_list->table->file->get_parent_foreign_key_list(thd, &fk_list);
  if (thd->is_error())
  {
    if (arena)
      thd->restore_active_arena(arena, &backup);
    return TRUE;
  }

  *need_prelocking= TRUE;

  while ((fk= fk_list_it++))
  {
    // FK_OPTION_RESTRICT and FK_OPTION_NO_ACTION only need read access
    static bool can_write[]= { true, false, true, true, false, true };
    thr_lock_type lock_type;

    if ((op & (1 << TRG_EVENT_DELETE) && can_write[fk->delete_method])
        || (op & (1 << TRG_EVENT_UPDATE) && can_write[fk->update_method]))
      lock_type= TL_WRITE_ALLOW_WRITE;
    else
      lock_type= TL_READ;

    if (table_already_fk_prelocked(prelocking_ctx->query_tables,
          fk->foreign_db, fk->foreign_table,
          lock_type))
      continue;

    TABLE_LIST *tl= (TABLE_LIST *) thd->alloc(sizeof(TABLE_LIST));
    tl->init_one_table_for_prelocking(fk->foreign_db->str, fk->foreign_db->length,
        fk->foreign_table->str, fk->foreign_table->length,
        NULL, lock_type, false, table_list->belong_to_view,
        op, &prelocking_ctx->query_tables_last);
  }
  if (arena)
    thd->restore_active_arena(arena, &backup);

  return FALSE;
}


Field *find_field_in_table_sef(TABLE *table, const char *name)
{
  Field **field_ptr;
  if (table->s->name_hash.records)
  {
    field_ptr= (Field**)my_hash_search(&table->s->name_hash,(uchar*) name,
                                       strlen(name));
    if (field_ptr)
    {
      /*
        field_ptr points to field in TABLE_SHARE. Convert it to the matching
        field in table
      */
      field_ptr= (table->field + (field_ptr - table->s->field));
    }
  }
  else
  {
    if (!(field_ptr= table->field))
      return (Field *)0;
    for (; *field_ptr; ++field_ptr)
      if (!my_strcasecmp(system_charset_info, (*field_ptr)->field_name, name))
        break;
  }
  if (field_ptr)
    return *field_ptr;
  else
    return (Field *)0;
}


static bool open_table_entry_fini(THD *thd, TABLE_SHARE *share, TABLE *entry)
{
  if (Table_triggers_list::check_n_load(thd, share->db.str,
                                        share->table_name.str, entry, 0))
    return TRUE;

  /*
    If we are here, there was no fatal error (but error may be still
    unitialized).
  */
  if (unlikely(entry->file->implicit_emptied))
  {
    entry->file->implicit_emptied= 0;
    if (mysql_bin_log.is_open())
    {
      char query_buf[2*FN_REFLEN + 21];
      String query(query_buf, sizeof(query_buf), system_charset_info);

      query.length(0);
      query.append("DELETE FROM ");
      append_identifier(thd, &query, share->db.str, share->db.length);
      query.append(".");
      append_identifier(thd, &query, share->table_name.str,
                          share->table_name.length);

      /*
        we bypass thd->binlog_query() here,
        as it does a lot of extra work, that is simply wrong in this case
      */
      Query_log_event qinfo(thd, query.ptr(), query.length(),
                            FALSE, TRUE, TRUE, 0);
      if (mysql_bin_log.write(&qinfo))
        return TRUE;
    }
  }
  return FALSE;
}


store_top_level_join_columns(THD *thd, TABLE_LIST *table_ref,
                             TABLE_LIST *left_neighbor,
                             TABLE_LIST *right_neighbor)
{
  Query_arena *arena, backup;
  bool result= TRUE;

  DBUG_ENTER("store_top_level_join_columns");

  arena= thd->activate_stmt_arena_if_needed(&backup);

  /* Call the procedure recursively for each nested table reference. */
  if (table_ref->nested_join)
  {
    List_iterator_fast<TABLE_LIST> nested_it(table_ref->nested_join->join_list);
    TABLE_LIST *same_level_left_neighbor= nested_it++;
    TABLE_LIST *same_level_right_neighbor= NULL;
    /* Left/right-most neighbors, possibly at higher levels in the join tree. */
    TABLE_LIST *real_left_neighbor, *real_right_neighbor;

    while (same_level_left_neighbor)
    {
      TABLE_LIST *cur_table_ref= same_level_left_neighbor;
      same_level_left_neighbor= nested_it++;
      /*
        The order of RIGHT JOIN operands is reversed in 'join list' to
        transform it into a LEFT JOIN. However, in this procedure we need
        the join operands in their lexical order, so below we reverse the
        join operands. Notice that this happens only in the first loop,
        and not in the second one, as in the second loop
        same_level_left_neighbor == NULL.
        This is the correct behavior, because the second loop sets
        cur_table_ref reference correctly after the join operands are
        swapped in the first loop.
      */
      if (same_level_left_neighbor &&
          cur_table_ref->outer_join & JOIN_TYPE_RIGHT)
      {
        /* This can happen only for JOIN ... ON. */
        DBUG_ASSERT(table_ref->nested_join->join_list.elements == 2);
        swap_variables(TABLE_LIST*, same_level_left_neighbor, cur_table_ref);
      }

      /*
        Pick the parent's left and right neighbors if there are no immediate
        neighbors at the same level.
      */
      real_left_neighbor=  (same_level_left_neighbor) ?
                           same_level_left_neighbor : left_neighbor;
      real_right_neighbor= (same_level_right_neighbor) ?
                           same_level_right_neighbor : right_neighbor;

      if (cur_table_ref->nested_join &&
          store_top_level_join_columns(thd, cur_table_ref,
                                       real_left_neighbor, real_right_neighbor))
        goto err;
      same_level_right_neighbor= cur_table_ref;
    }
  }

  /*
    If this is a NATURAL/USING join, materialize its result columns and
    convert to a JOIN ... ON.
  */
  if (table_ref->is_natural_join)
  {
    DBUG_ASSERT(table_ref->nested_join &&
                table_ref->nested_join->join_list.elements == 2);
    List_iterator_fast<TABLE_LIST> operand_it(table_ref->nested_join->join_list);
    /*
      Notice that the order of join operands depends on whether table_ref
      represents a LEFT or a RIGHT join. In a RIGHT join, the operands are
      in inverted order.
     */
    TABLE_LIST *table_ref_2= operand_it++; /* Second NATURAL join operand.*/
    TABLE_LIST *table_ref_1= operand_it++; /* First NATURAL join operand. */
    List<String> *using_fields= table_ref->join_using_fields;
    uint found_using_fields;

    /*
      The two join operands were interchanged in the parser, change the order
      back for 'mark_common_columns'.
    */
    if (table_ref_2->outer_join & JOIN_TYPE_RIGHT)
      swap_variables(TABLE_LIST*, table_ref_1, table_ref_2);
    if (mark_common_columns(thd, table_ref_1, table_ref_2,
                            using_fields, &found_using_fields))
      goto err;

    /*
      Swap the join operands back, so that we pick the columns of the second
      one as the coalesced columns. In this way the coalesced columns are the
      same as of an equivalent LEFT JOIN.
    */
    if (table_ref_1->outer_join & JOIN_TYPE_RIGHT)
      swap_variables(TABLE_LIST*, table_ref_1, table_ref_2);
    if (store_natural_using_join_columns(thd, table_ref, table_ref_1,
                                         table_ref_2, using_fields,
                                         found_using_fields))
      goto err;

    /*
      Change NATURAL JOIN to JOIN ... ON. We do this for both operands
      because either one of them or the other is the one with the
      natural join flag because RIGHT joins are transformed into LEFT,
      and the two tables may be reordered.
    */
    table_ref_1->natural_join= table_ref_2->natural_join= NULL;

    /* Add a TRUE condition to outer joins that have no common columns. */
    if (table_ref_2->outer_join &&
        !table_ref_1->on_expr && !table_ref_2->on_expr)
      table_ref_2->on_expr= new (thd->mem_root) Item_int(thd, (longlong) 1, 1); // Always true.

    /* Change this table reference to become a leaf for name resolution. */
    if (left_neighbor)
    {
      TABLE_LIST *last_leaf_on_the_left;
      last_leaf_on_the_left= left_neighbor->last_leaf_for_name_resolution();
      last_leaf_on_the_left->next_name_resolution_table= table_ref;
    }
    if (right_neighbor)
    {
      TABLE_LIST *first_leaf_on_the_right;
      first_leaf_on_the_right= right_neighbor->first_leaf_for_name_resolution();
      table_ref->next_name_resolution_table= first_leaf_on_the_right;
    }
    else
      table_ref->next_name_resolution_table= NULL;
  }
  result= FALSE; /* All is OK. */

err:
  if (arena)
    thd->restore_active_arena(arena, &backup);
  DBUG_RETURN(result);
}


mark_common_columns(THD *thd, TABLE_LIST *table_ref_1, TABLE_LIST *table_ref_2,
                    List<String> *using_fields, uint *found_using_fields)
{
  Field_iterator_table_ref it_1, it_2;
  Natural_join_column *nj_col_1, *nj_col_2;
  Query_arena *arena, backup;
  bool result= TRUE;
  bool first_outer_loop= TRUE;
  /*
    Leaf table references to which new natural join columns are added
    if the leaves are != NULL.
  */
  TABLE_LIST *leaf_1= (table_ref_1->nested_join &&
                       !table_ref_1->is_natural_join) ?
                      NULL : table_ref_1;
  TABLE_LIST *leaf_2= (table_ref_2->nested_join &&
                       !table_ref_2->is_natural_join) ?
                      NULL : table_ref_2;

  DBUG_ENTER("mark_common_columns");
  DBUG_PRINT("info", ("operand_1: %s  operand_2: %s",
                      table_ref_1->alias, table_ref_2->alias));

  *found_using_fields= 0;
  arena= thd->activate_stmt_arena_if_needed(&backup);

  for (it_1.set(table_ref_1); !it_1.end_of_fields(); it_1.next())
  {
    bool found= FALSE;
    const char *field_name_1;
    /* true if field_name_1 is a member of using_fields */
    bool is_using_column_1;
    if (!(nj_col_1= it_1.get_or_create_column_ref(thd, leaf_1)))
      goto err;
    field_name_1= nj_col_1->name();
    is_using_column_1= using_fields &&
      test_if_string_in_list(field_name_1, using_fields);
    DBUG_PRINT ("info", ("field_name_1=%s.%s",
                         nj_col_1->table_name() ? nj_col_1->table_name() : "",
                         field_name_1));

    /*
      Find a field with the same name in table_ref_2.

      Note that for the second loop, it_2.set() will iterate over
      table_ref_2->join_columns and not generate any new elements or
      lists.
    */
    nj_col_2= NULL;
    for (it_2.set(table_ref_2); !it_2.end_of_fields(); it_2.next())
    {
      Natural_join_column *cur_nj_col_2;
      const char *cur_field_name_2;
      if (!(cur_nj_col_2= it_2.get_or_create_column_ref(thd, leaf_2)))
        goto err;
      cur_field_name_2= cur_nj_col_2->name();
      DBUG_PRINT ("info", ("cur_field_name_2=%s.%s",
                           cur_nj_col_2->table_name() ?
                             cur_nj_col_2->table_name() : "",
                           cur_field_name_2));

      /*
        Compare the two columns and check for duplicate common fields.
        A common field is duplicate either if it was already found in
        table_ref_2 (then found == TRUE), or if a field in table_ref_2
        was already matched by some previous field in table_ref_1
        (then cur_nj_col_2->is_common == TRUE).
        Note that it is too early to check the columns outside of the
        USING list for ambiguity because they are not actually "referenced"
        here. These columns must be checked only on unqualified reference
        by name (e.g. in SELECT list).
      */
      if (!my_strcasecmp(system_charset_info, field_name_1, cur_field_name_2))
      {
        DBUG_PRINT ("info", ("match c1.is_common=%d", nj_col_1->is_common));
        if (cur_nj_col_2->is_common ||
            (found && (!using_fields || is_using_column_1)))
        {
          my_error(ER_NON_UNIQ_ERROR, MYF(0), field_name_1, thd->where);
          goto err;
        }
        nj_col_2= cur_nj_col_2;
        found= TRUE;
      }
    }
    if (first_outer_loop && leaf_2)
    {
      /*
        Make sure that the next inner loop "knows" that all columns
        are materialized already.
      */
      leaf_2->is_join_columns_complete= TRUE;
      first_outer_loop= FALSE;
    }
    if (!found)
      continue;                                 // No matching field

    /*
      field_1 and field_2 have the same names. Check if they are in the USING
      clause (if present), mark them as common fields, and add a new
      equi-join condition to the ON clause.
    */
    if (nj_col_2 && (!using_fields ||is_using_column_1))
    {
      /*
        Create non-fixed fully qualified field and let fix_fields to
        resolve it.
      */
      Item *item_1=   nj_col_1->create_item(thd);
      Item *item_2=   nj_col_2->create_item(thd);
      Field *field_1= nj_col_1->field();
      Field *field_2= nj_col_2->field();
      Item_ident *item_ident_1, *item_ident_2;
      Item_func_eq *eq_cond;

      if (!item_1 || !item_2)
        goto err;                               // out of memory

      /*
        The following assert checks that the two created items are of
        type Item_ident.
      */
      DBUG_ASSERT(!thd->lex->current_select->no_wrap_view_item);
      /*
        In the case of no_wrap_view_item == 0, the created items must be
        of sub-classes of Item_ident.
      */
      DBUG_ASSERT(item_1->type() == Item::FIELD_ITEM ||
                  item_1->type() == Item::REF_ITEM);
      DBUG_ASSERT(item_2->type() == Item::FIELD_ITEM ||
                  item_2->type() == Item::REF_ITEM);

      /*
        We need to cast item_1,2 to Item_ident, because we need to hook name
        resolution contexts specific to each item.
      */
      item_ident_1= (Item_ident*) item_1;
      item_ident_2= (Item_ident*) item_2;
      /*
        Create and hook special name resolution contexts to each item in the
        new join condition . We need this to both speed-up subsequent name
        resolution of these items, and to enable proper name resolution of
        the items during the execute phase of PS.
      */
      if (set_new_item_local_context(thd, item_ident_1, nj_col_1->table_ref) ||
          set_new_item_local_context(thd, item_ident_2, nj_col_2->table_ref))
        goto err;

      if (!(eq_cond= new (thd->mem_root) Item_func_eq(thd, item_ident_1, item_ident_2)))
        goto err;                               /* Out of memory. */

      if (field_1 && field_1->vcol_info)
        field_1->table->mark_virtual_col(field_1);
      if (field_2 && field_2->vcol_info)
        field_2->table->mark_virtual_col(field_2);

      /*
        Add the new equi-join condition to the ON clause. Notice that
        fix_fields() is applied to all ON conditions in setup_conds()
        so we don't do it here.
      */
      add_join_on(thd, (table_ref_1->outer_join & JOIN_TYPE_RIGHT ?
                        table_ref_1 : table_ref_2),
                  eq_cond);

      nj_col_1->is_common= nj_col_2->is_common= TRUE;
      DBUG_PRINT ("info", ("%s.%s and %s.%s are common",
                           nj_col_1->table_name() ?
                             nj_col_1->table_name() : "",
                           nj_col_1->name(),
                           nj_col_2->table_name() ?
                             nj_col_2->table_name() : "",
                           nj_col_2->name()));

      if (field_1)
      {
        TABLE *table_1= nj_col_1->table_ref->table;
        /* Mark field_1 used for table cache. */
        bitmap_set_bit(table_1->read_set, field_1->field_index);
        table_1->covering_keys.intersect(field_1->part_of_key);
      }
      if (field_2)
      {
        TABLE *table_2= nj_col_2->table_ref->table;
        /* Mark field_2 used for table cache. */
        bitmap_set_bit(table_2->read_set, field_2->field_index);
        table_2->covering_keys.intersect(field_2->part_of_key);
      }

      if (using_fields != NULL)
        ++(*found_using_fields);
    }
  }
  if (leaf_1)
    leaf_1->is_join_columns_complete= TRUE;

  /*
    Everything is OK.
    Notice that at this point there may be some column names in the USING
    clause that are not among the common columns. This is an SQL error and
    we check for this error in store_natural_using_join_columns() when
    (found_using_fields < length(join_using_fields)).
  */
  result= FALSE;

err:
  if (arena)
    thd->restore_active_arena(arena, &backup);
  DBUG_RETURN(result);
}


open_and_process_routine(THD *thd, Query_tables_list *prelocking_ctx,
                         Sroutine_hash_entry *rt,
                         Prelocking_strategy *prelocking_strategy,
                         bool has_prelocking_list,
                         Open_table_context *ot_ctx,
                         bool *need_prelocking, bool *routine_modifies_data)
{
  MDL_key::enum_mdl_namespace mdl_type= rt->mdl_request.key.mdl_namespace();
  DBUG_ENTER("open_and_process_routine");

  *routine_modifies_data= false;

  switch (mdl_type)
  {
  case MDL_key::FUNCTION:
  case MDL_key::PROCEDURE:
    {
      sp_head *sp;
      /*
        Try to get MDL lock on the routine.
        Note that we do not take locks on top-level CALLs as this can
        lead to a deadlock. Not locking top-level CALLs does not break
        the binlog as only the statements in the called procedure show
        up there, not the CALL itself.
      */
      if (rt != (Sroutine_hash_entry*)prelocking_ctx->sroutines_list.first ||
          mdl_type != MDL_key::PROCEDURE)
      {
        /*
          Since we acquire only shared lock on routines we don't
          need to care about global intention exclusive locks.
        */
        DBUG_ASSERT(rt->mdl_request.type == MDL_SHARED);

        /*
          Waiting for a conflicting metadata lock to go away may
          lead to a deadlock, detected by MDL subsystem.
          If possible, we try to resolve such deadlocks by releasing all
          metadata locks and restarting the pre-locking process.
          To prevent the error from polluting the diagnostics area
          in case of successful resolution, install a special error
          handler for ER_LOCK_DEADLOCK error.
        */
        MDL_deadlock_handler mdl_deadlock_handler(ot_ctx);

        thd->push_internal_handler(&mdl_deadlock_handler);
        bool result= thd->mdl_context.acquire_lock(&rt->mdl_request,
                                                   ot_ctx->get_timeout());
        thd->pop_internal_handler();

        if (result)
          DBUG_RETURN(TRUE);

        DEBUG_SYNC(thd, "after_shared_lock_pname");

        /* Ensures the routine is up-to-date and cached, if exists. */
        if (sp_cache_routine(thd, rt, has_prelocking_list, &sp))
          DBUG_RETURN(TRUE);

        /* Remember the version of the routine in the parse tree. */
        if (check_and_update_routine_version(thd, rt, sp))
          DBUG_RETURN(TRUE);

        /* 'sp' is NULL when there is no such routine. */
        if (sp)
        {
          *routine_modifies_data= sp->modifies_data();

          if (!has_prelocking_list)
            prelocking_strategy->handle_routine(thd, prelocking_ctx, rt, sp,
                                                need_prelocking);
        }
      }
      else
      {
        /*
          If it's a top level call, just make sure we have a recent
          version of the routine, if it exists.
          Validating routine version is unnecessary, since CALL
          does not affect the prepared statement prelocked list.
        */
        if (sp_cache_routine(thd, rt, FALSE, &sp))
          DBUG_RETURN(TRUE);
      }
    }
    break;
  case MDL_key::TRIGGER:
    /**
      We add trigger entries to lex->sroutines_list, but we don't
      load them here. The trigger entry is only used when building
      a transitive closure of objects used in a statement, to avoid
      adding to this closure objects that are used in the trigger more
      than once.
      E.g. if a trigger trg refers to table t2, and the trigger table t1
      is used multiple times in the statement (say, because it's used in
      function f1() twice), we will only add t2 once to the list of
      tables to prelock.

      We don't take metadata locks on triggers either: they are protected
      by a respective lock on the table, on which the trigger is defined.

      The only two cases which give "trouble" are SHOW CREATE TRIGGER
      and DROP TRIGGER statements. For these, statement syntax doesn't
      specify the table on which this trigger is defined, so we have
      to make a "dirty" read in the data dictionary to find out the
      table name. Once we discover the table name, we take a metadata
      lock on it, and this protects all trigger operations.
      Of course the table, in theory, may disappear between the dirty
      read and metadata lock acquisition, but in that case we just return
      a run-time error.

      Grammar of other trigger DDL statements (CREATE, DROP) requires
      the table to be specified explicitly, so we use the table metadata
      lock to protect trigger metadata in these statements. Similarly, in
      DML we always use triggers together with their tables, and thus don't
      need to take separate metadata locks on them.
    */
    break;
  default:
    /* Impossible type value. */
    DBUG_ASSERT(0);
  }
  DBUG_RETURN(FALSE);
}


void unfix_fields(List<Item> &fields)
{
  List_iterator<Item> li(fields);
  Item *item;
  while ((item= li++))
    item->fixed= 0;
}


TABLE_LIST* find_dup_table(THD *thd, TABLE_LIST *table, TABLE_LIST *table_list,
                           uint check_flag)
{
  TABLE_LIST *res= 0;
  const char *d_name, *t_name, *t_alias;
  DBUG_ENTER("find_dup_table");
  DBUG_PRINT("enter", ("table alias: %s", table->alias));

  /*
    If this function called for query which update table (INSERT/UPDATE/...)
    then we have in table->table pointer to TABLE object which we are
    updating even if it is VIEW so we need TABLE_LIST of this TABLE object
    to get right names (even if lower_case_table_names used).

    If this function called for CREATE command that we have not opened table
    (table->table equal to 0) and right names is in current TABLE_LIST
    object.
  */
  if (table->table)
  {
    /* All MyISAMMRG children are plain MyISAM tables. */
    DBUG_ASSERT(table->table->file->ht->db_type != DB_TYPE_MRG_MYISAM);

    table= table->find_underlying_table(table->table);
    /*
      as far as we have table->table we have to find real TABLE_LIST of
      it in underlying tables
    */
    DBUG_ASSERT(table);
  }
  d_name= table->db;
  t_name= table->table_name;
  t_alias= table->alias;

retry:
  DBUG_PRINT("info", ("real table: %s.%s", d_name, t_name));
  for (TABLE_LIST *tl= table_list; tl ; tl= tl->next_global, res= 0)
  {
    if (tl->select_lex && tl->select_lex->master_unit() &&
        tl->select_lex->master_unit()->executed)
    {
      /*
        There is no sense to check tables of already executed parts
        of the query
      */
      continue;
    }
    /*
      Table is unique if it is present only once in the global list
      of tables and once in the list of table locks.
    */
    if (! (res= find_table_in_global_list(tl, d_name, t_name)))
      break;
    tl= res;                       // We can continue search after this table

    /* Skip if same underlying table. */
    if (res->table && (res->table == table->table))
      continue;

    /* Skip if table is tmp table */
    if (check_flag & CHECK_DUP_SKIP_TEMP_TABLE &&
        res->table && res->table->s->tmp_table != NO_TMP_TABLE)
    {
      continue;
    }
    if (check_flag & CHECK_DUP_FOR_CREATE)
      DBUG_RETURN(res);

    /* Skip if table alias does not match. */
    if (check_flag & CHECK_DUP_ALLOW_DIFFERENT_ALIAS)
    {
      if (my_strcasecmp(table_alias_charset, t_alias, res->alias))
        continue;
    }

    /*
      If table is not excluded (could be a derived table) and table is not
      a prelocking placeholder then we found either a duplicate entry
      or a table that is part of a derived table (handled below).
      Examples are:
      INSERT INTO t1 SELECT * FROM t1;
      INSERT INTO t1 SELECT * FROM view_containing_t1;
    */
    if (res->select_lex &&
        !res->select_lex->exclude_from_table_unique_test &&
        !res->prelocking_placeholder)
      break;

    /*
      If we found entry of this table or table of SELECT which already
      processed in derived table or top select of multi-update/multi-delete
      (exclude_from_table_unique_test) or prelocking placeholder.
    */
    DBUG_PRINT("info",
               ("found same copy of table or table which we should skip"));
  }
  if (res && res->belong_to_derived)
  {
    /*
      We come here for queries of type:
      INSERT INTO t1 (SELECT tmp.a FROM (select * FROM t1) as tmp);

      Try to fix by materializing the derived table
    */
    TABLE_LIST *derived=  res->belong_to_derived;
    if (derived->is_merged_derived() && !derived->derived->is_excluded())
    {
      DBUG_PRINT("info",
                 ("convert merged to materialization to resolve the conflict"));
      derived->change_refs_to_fields();
      derived->set_materialized_derived();
      goto retry;
    }
  }
  DBUG_RETURN(res);
}


MDEV-26351 segfault - (MARIA_HA *) 0x0 in ha_maria::extra

don't let Aria create a table that it cannot open

uint maria_get_pointer_length(ulonglong file_length, uint def)
{
  DBUG_ASSERT(def >= 2 && def <= 7);
  if (file_length)				/* If not default */
  {
#ifdef NOT_YET_READY_FOR_8_BYTE_POINTERS
    if (file_length >= (1ULL << 56))
      def=8;
    else
#endif
      if (file_length >= (1ULL << 48))
      def=7;
    else if (file_length >= (1ULL << 40))
      def=6;
    else if (file_length >= (1ULL << 32))
      def=5;
    else if (file_length >= (1ULL << 24))
      def=4;
    else if (file_length >= (1ULL << 16))
      def=3;
    else
      def=2;
  }
  return def;
}

MariaDB through 10.5.13 allows a ha_maria::extra application crash via certain SELECT statements.


int _ma_initialize_data_file(MARIA_SHARE *share, File dfile)
{
  if (share->data_file_type == BLOCK_RECORD)
  {
    share->bitmap.block_size= share->base.block_size;
    share->bitmap.file.file = dfile;
    return _ma_bitmap_create_first(share);
  }
  return 0;
}


static int compare_columns(MARIA_COLUMNDEF **a_ptr, MARIA_COLUMNDEF **b_ptr)
{
  MARIA_COLUMNDEF *a= *a_ptr, *b= *b_ptr;
  enum en_fieldtype a_type, b_type;

  a_type= (a->type == FIELD_CHECK) ? FIELD_NORMAL : a->type;
  b_type= (b->type == FIELD_CHECK) ? FIELD_NORMAL : b->type;

  if (a_type == FIELD_NORMAL && !a->null_bit)
  {
    if (b_type != FIELD_NORMAL || b->null_bit)
      return -1;
    return sign((long) a->offset - (long) b->offset);
  }
  if (b_type == FIELD_NORMAL && !b->null_bit)
    return 1;
  if (a_type == b_type)
    return sign((long) a->offset - (long) b->offset);
  if (a_type == FIELD_NORMAL)
    return -1;
  if (b_type == FIELD_NORMAL)
    return 1;
  if (a_type == FIELD_SKIP_ZERO)
    return -1;
  if (b_type == FIELD_SKIP_ZERO)
    return 1;
  if (a->type != FIELD_BLOB && b->type != FIELD_BLOB)
    if (a->length != b->length)
      return sign((long) a->length - (long) b->length);
  if (a_type == FIELD_BLOB)
    return 1;
  if (b_type == FIELD_BLOB)
    return -1;
  return sign((long) a->offset - (long) b->offset);
}


int _ma_update_state_lsns(MARIA_SHARE *share, LSN lsn, TrID create_trid,
                          my_bool do_sync, my_bool update_create_rename_lsn)
{
  int res;
  DBUG_ENTER("_ma_update_state_lsns");
  mysql_mutex_lock(&share->intern_lock);
  res= _ma_update_state_lsns_sub(share, lsn, create_trid, do_sync,
                                 update_create_rename_lsn);
  mysql_mutex_unlock(&share->intern_lock);
  DBUG_RETURN(res);
}


int _ma_update_state_lsns_sub(MARIA_SHARE *share, LSN lsn, TrID create_trid,
                              my_bool do_sync,
                              my_bool update_create_rename_lsn)
{
  uchar buf[LSN_STORE_SIZE * 3], *ptr;
  uchar trid_buff[8];
  File file= share->kfile.file;
  DBUG_ASSERT(file >= 0);

  if (lsn == LSN_IMPOSSIBLE)
  {
    int res;
    LEX_CUSTRING log_array[TRANSLOG_INTERNAL_PARTS + 1];
    /* table name is logged only for information */
    log_array[TRANSLOG_INTERNAL_PARTS + 0].str=
      (uchar *)(share->open_file_name.str);
    log_array[TRANSLOG_INTERNAL_PARTS + 0].length=
      share->open_file_name.length + 1;
    if ((res= translog_write_record(&lsn, LOGREC_IMPORTED_TABLE,
                                    &dummy_transaction_object, NULL,
                                    (translog_size_t)
                                    log_array[TRANSLOG_INTERNAL_PARTS +
                                              0].length,
                                    sizeof(log_array)/sizeof(log_array[0]),
                                    log_array, NULL, NULL)))
      return res;
  }

  for (ptr= buf; ptr < (buf + sizeof(buf)); ptr+= LSN_STORE_SIZE)
    lsn_store(ptr, lsn);
  share->state.skip_redo_lsn= share->state.is_of_horizon= lsn;
  share->state.create_trid= create_trid;
  mi_int8store(trid_buff, create_trid);

  /*
    Update create_rename_lsn if update was requested or if the old one had an
    impossible value.
  */
  if (update_create_rename_lsn ||
      (share->state.create_rename_lsn > lsn && lsn != LSN_IMPOSSIBLE))
  {
    share->state.create_rename_lsn= lsn;
    if (share->id != 0)
    {
      /*
        If OP is the operation which is calling us, if table is later written,
        we could see in the log:
        FILE_ID ... REDO_OP ... REDO_INSERT.
        (that can happen in real life at least with OP=REPAIR).
        As FILE_ID will be ignored by Recovery because it is <
        create_rename_lsn, REDO_INSERT would be ignored too, wrongly.
        To avoid that, we force a LOGREC_FILE_ID to be logged at next write:
      */
      translog_deassign_id_from_share(share);
    }
  }
  else
    lsn_store(buf, share->state.create_rename_lsn);
  return (my_pwrite(file, buf, sizeof(buf),
                    sizeof(share->state.header) +
                    MARIA_FILE_CREATE_RENAME_LSN_OFFSET, MYF(MY_NABP)) ||
          my_pwrite(file, trid_buff, sizeof(trid_buff),
                    sizeof(share->state.header) +
                    MARIA_FILE_CREATE_TRID_OFFSET, MYF(MY_NABP)) ||
          (do_sync && mysql_file_sync(file, MYF(0))));
}


static inline int sign(long a)
{
  return a < 0 ? -1 : (a > 0 ? 1 : 0);
}


static ulonglong update_tot_length(ulonglong tot_length, ulonglong max_rows, uint length)
{
  ulonglong tot_length_part;

  if (tot_length == ULONGLONG_MAX)
    return ULONGLONG_MAX;

  tot_length_part= (max_rows/(ulong) ((maria_block_size -
                    MAX_KEYPAGE_HEADER_SIZE - KEYPAGE_CHECKSUM_SIZE)/
                    (length*2)));
  if (tot_length_part >=  ULONGLONG_MAX / maria_block_size)
    return ULONGLONG_MAX;

  if (tot_length > ULONGLONG_MAX - tot_length_part * maria_block_size)
    return ULONGLONG_MAX;

  return tot_length + tot_length_part * maria_block_size;
}