MDEV-20229 CTE defined with table value constructor cannot be used in views

A CTE can be defined as a table values constructor. In this case the CTE is
always materialized in a temporary table.
If the definition of the CTE contains a list of the names of the CTE
columns then the query expression that uses this CTE can refer to the CTE
columns by these names. Otherwise the names of the columns are taken from
the names of the columns in the result set of the query that specifies the
CTE.
Thus if the column names of a CTE are provided in the definition the
columns of result set should be renamed. In a general case renaming of
the columns is done in the select lists of the query specifying the CTE.
If a CTE is specified by a table value constructor then there are no such
select lists and renaming is actually done for the columns of the result
of materialization.
Now if a view is specified by a query expression that uses a CTE specified
by a table value constructor saving the column names of the CTE in the
stored view definition becomes critical: without these names the query
expression is not able to refer to the columns of the CTE.

This patch saves the given column names of CTEs in stored view definitions
that use them.

mysql-test/main/cte_nonrecursive.result

@@ -606,7 +606,7 @@ with t(c) as (select a from t1 where b >= 'c')
 select * from t r1 where r1.c=4;
 show create view v3;
 View	Create View	character_set_client	collation_connection
-v3	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v3` AS with t as (select `t1`.`a` AS `c` from `t1` where `t1`.`b` >= 'c')select `r1`.`c` AS `c` from `t` `r1` where `r1`.`c` = 4	latin1	latin1_swedish_ci
+v3	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v3` AS with t(c) as (select `t1`.`a` AS `c` from `t1` where `t1`.`b` >= 'c')select `r1`.`c` AS `c` from `t` `r1` where `r1`.`c` = 4	latin1	latin1_swedish_ci
 select * from v3;
 c
 4
@@ -618,7 +618,7 @@ with t(c) as (select a from t1 where b >= 'c')
 select * from t r1, t r2 where r1.c=r2.c and r2.c=4;
 show create view v4;
 View	Create View	character_set_client	collation_connection
-v4	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v4` AS with t as (select `test`.`t1`.`a` AS `c` from `test`.`t1` where `test`.`t1`.`b` >= 'c')select `r1`.`c` AS `c`,`r2`.`c` AS `d` from (`t` `r1` join (select `test`.`t1`.`a` AS `c` from `test`.`t1` where `test`.`t1`.`b` >= 'c') `r2`) where `r1`.`c` = `r2`.`c` and `r2`.`c` = 4	latin1	latin1_swedish_ci
+v4	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v4` AS with t(c) as (select `test`.`t1`.`a` AS `c` from `test`.`t1` where `test`.`t1`.`b` >= 'c')select `r1`.`c` AS `c`,`r2`.`c` AS `d` from (`t` `r1` join (select `test`.`t1`.`a` AS `c` from `test`.`t1` where `test`.`t1`.`b` >= 'c') `r2`) where `r1`.`c` = `r2`.`c` and `r2`.`c` = 4	latin1	latin1_swedish_ci
 select * from v4;
 c	d
 4	4

mysql-test/main/cte_recursive.result

@@ -699,7 +699,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 5	RECURSIVE UNION	p	ALL	NULL	NULL	NULL	NULL	12	100.00	Using where; Using join buffer (flat, BNL join)
 NULL	UNION RESULT	<union3,4,5>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	with recursive ancestor_couple_ids as (/* select#2 */ select `a`.`father` AS `h_id`,`a`.`mother` AS `w_id` from `coupled_ancestors` `a` where `a`.`father` is not null and `a`.`mother` is not null), coupled_ancestors as (/* select#3 */ select `test`.`folks`.`id` AS `id`,`test`.`folks`.`name` AS `name`,`test`.`folks`.`dob` AS `dob`,`test`.`folks`.`father` AS `father`,`test`.`folks`.`mother` AS `mother` from `test`.`folks` where `test`.`folks`.`name` = 'Me' union all /* select#4 */ select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `fa` where `test`.`p`.`id` = `fa`.`h_id` union all /* select#5 */ select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `ma` where `test`.`p`.`id` = `ma`.`w_id`)/* select#1 */ select `h`.`name` AS `name`,`h`.`dob` AS `dob`,`w`.`name` AS `name`,`w`.`dob` AS `dob` from `ancestor_couple_ids` `c` join `coupled_ancestors` `h` join `coupled_ancestors` `w` where `h`.`id` = `c`.`h_id` and `w`.`id` = `c`.`w_id`
+Note	1003	with recursive ancestor_couple_ids(h_id,w_id) as (/* select#2 */ select `a`.`father` AS `h_id`,`a`.`mother` AS `w_id` from `coupled_ancestors` `a` where `a`.`father` is not null and `a`.`mother` is not null), coupled_ancestors(id,name,dob,father,mother) as (/* select#3 */ select `test`.`folks`.`id` AS `id`,`test`.`folks`.`name` AS `name`,`test`.`folks`.`dob` AS `dob`,`test`.`folks`.`father` AS `father`,`test`.`folks`.`mother` AS `mother` from `test`.`folks` where `test`.`folks`.`name` = 'Me' union all /* select#4 */ select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `fa` where `test`.`p`.`id` = `fa`.`h_id` union all /* select#5 */ select `test`.`p`.`id` AS `id`,`test`.`p`.`name` AS `name`,`test`.`p`.`dob` AS `dob`,`test`.`p`.`father` AS `father`,`test`.`p`.`mother` AS `mother` from `test`.`folks` `p` join `ancestor_couple_ids` `ma` where `test`.`p`.`id` = `ma`.`w_id`)/* select#1 */ select `h`.`name` AS `name`,`h`.`dob` AS `dob`,`w`.`name` AS `name`,`w`.`dob` AS `dob` from `ancestor_couple_ids` `c` join `coupled_ancestors` `h` join `coupled_ancestors` `w` where `h`.`id` = `c`.`h_id` and `w`.`id` = `c`.`w_id`
 # simple mutual recursion
 with recursive
 ancestor_couple_ids(h_id, w_id)
@@ -3091,7 +3091,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 4	DEPENDENT SUBQUERY	<derived2>	ALL	NULL	NULL	NULL	NULL	16	100.00	Using where
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	with recursive destinations as (/* select#2 */ select `test`.`a`.`arrival` AS `city`,1 AS `legs` from `test`.`flights` `a` where `test`.`a`.`departure` = 'Cairo' union /* select#3 */ select `test`.`b`.`arrival` AS `arrival`,`r`.`legs` + 1 AS `r.legs + 1` from `destinations` `r` join `test`.`flights` `b` where `r`.`city` = `test`.`b`.`departure` and !<in_optimizer>(`test`.`b`.`arrival`,<exists>(/* select#4 */ select `destinations`.`city` from `destinations` where trigcond(`test`.`b`.`arrival` = `destinations`.`city` or `destinations`.`city` is null) having trigcond(`destinations`.`city` is null))))/* select#1 */ select `destinations`.`city` AS `city`,`destinations`.`legs` AS `legs` from `destinations`
+Note	1003	with recursive destinations(city,legs) as (/* select#2 */ select `test`.`a`.`arrival` AS `city`,1 AS `legs` from `test`.`flights` `a` where `test`.`a`.`departure` = 'Cairo' union /* select#3 */ select `test`.`b`.`arrival` AS `arrival`,`r`.`legs` + 1 AS `r.legs + 1` from `destinations` `r` join `test`.`flights` `b` where `r`.`city` = `test`.`b`.`departure` and !<in_optimizer>(`test`.`b`.`arrival`,<exists>(/* select#4 */ select `destinations`.`city` from `destinations` where trigcond(`test`.`b`.`arrival` = `destinations`.`city` or `destinations`.`city` is null) having trigcond(`destinations`.`city` is null))))/* select#1 */ select `destinations`.`city` AS `city`,`destinations`.`legs` AS `legs` from `destinations`
 set standard_compliant_cte=default;
 drop table flights;
 #
@@ -3378,7 +3378,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 3	RECURSIVE UNION	<derived2>	ALL	NULL	NULL	NULL	NULL	2	100.00	Using where
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	NULL	
 Warnings:
-Note	1003	with recursive rcte as (/* select#2 */ select 1 AS `a` union /* select#3 */ select cast(`rcte`.`a` + 1 as unsigned) AS `cast(a+1 as unsigned)` from `rcte` where `rcte`.`a` < 10), cte1 as (/* select#4 */ select count(0) AS `c1` from `rcte` join `test`.`t1` where `rcte`.`a` between 3 and 5 and `test`.`t1`.`id` = `rcte`.`a` - 3), cte2 as (/* select#5 */ select count(0) AS `c2` from `rcte` join `test`.`t1` where `rcte`.`a` between 7 and 8 and `test`.`t1`.`id` = `rcte`.`a` - 7)/* select#1 */ select `cte1`.`c1` AS `c1`,`cte2`.`c2` AS `c2` from `cte1` join `cte2`
+Note	1003	with recursive rcte(a) as (/* select#2 */ select 1 AS `a` union /* select#3 */ select cast(`rcte`.`a` + 1 as unsigned) AS `cast(a+1 as unsigned)` from `rcte` where `rcte`.`a` < 10), cte1 as (/* select#4 */ select count(0) AS `c1` from `rcte` join `test`.`t1` where `rcte`.`a` between 3 and 5 and `test`.`t1`.`id` = `rcte`.`a` - 3), cte2 as (/* select#5 */ select count(0) AS `c2` from `rcte` join `test`.`t1` where `rcte`.`a` between 7 and 8 and `test`.`t1`.`id` = `rcte`.`a` - 7)/* select#1 */ select `cte1`.`c1` AS `c1`,`cte2`.`c2` AS `c2` from `cte1` join `cte2`
 prepare stmt from "with recursive
 rcte(a) as
 (select 1 union select cast(a+1 as unsigned) from rcte where a < 10),

mysql-test/main/table_value_constr.result

@@ -2586,3 +2586,16 @@ create view v1 as
 union
 ( values (5), (7), (1), (3), (4) order by 2 limit 2 );
 ERROR 42S22: Unknown column '2' in 'order clause'
+#
+# MDEV-20229: view defined as select using
+#             CTE with named columns defined as TVC
+#
+create view v1 as with t(a) as (values (2), (1)) select a from t;
+show create view v1;
+View	Create View	character_set_client	collation_connection
+v1	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS with t(a) as (values (2),(1))select `t`.`a` AS `a` from `t`	latin1	latin1_swedish_ci
+select * from v1;
+a
+2
+1
+drop view v1;

mysql-test/main/table_value_constr.test

@@ -1316,3 +1316,13 @@ create view v1 as
 ( values (5), (7), (1), (3), (4) limit 2 offset 1 )
   union
 ( values (5), (7), (1), (3), (4) order by 2 limit 2 );
+
+--echo #
+--echo # MDEV-20229: view defined as select using
+--echo #             CTE with named columns defined as TVC
+--echo #
+
+create view v1 as with t(a) as (values (2), (1)) select a from t;
+show create view v1;
+select * from v1;
+drop view v1;

sql/sql_cte.cc

@@ -1430,6 +1430,22 @@ void With_clause::print(String *str, enum_query_type query_type)
 void With_element::print(String *str, enum_query_type query_type)
 {
   str->append(query_name);
+  if (column_list.elements)
+  {
+    List_iterator_fast<LEX_CSTRING> li(column_list);
+    str->append('(');
+    for (LEX_CSTRING *col_name= li++; ; )
+    {
+      str->append(col_name);
+      col_name= li++;
+      if (!col_name)
+      {
+        str->append(')');
+        break;
+      }
+      str->append(',');
+    }
+  }
   str->append(STRING_WITH_LEN(" as "));
   str->append('(');
   spec->print(str, query_type);

sql/sql_union.cc

@@ -1858,6 +1858,7 @@ bool st_select_lex_unit::cleanup()
       DBUG_RETURN(FALSE);
     }
   }
+  columns_are_renamed= false;
   cleaned= 1;
 
   for (SELECT_LEX *sl= first_select(); sl; sl= sl->next_select())