MDEV-34931 MDEV-31466 name resolution fails in --view

Fix for MDEV-31466 - add optional derived table column names.
Column names within a SELECT_LEX structure can be left in a non-reparsable
state (as printed out from *::print) after JOIN::prepare.  This caused
an incorrect view definition to be written into the .FRM file.
Fixed by resetting item list names in SELECT_LEX structures representing
derived tables before writing out the view definition.

Reviewed by Igor Babaev (igor@mariadb.com)

Author: mariadb-RexJohnston

mysql-test/main/derived.result

@@ -2084,6 +2084,15 @@ union
 select c1, c2, sum(c3) as s from t2 group by c1, c2 having s > 3
 )
 as d2 (f1, f2, f3);
+create view v6 as select a1 from
+(
+select * from t1 union select * from t2 order by c1
+) as d3 (a1, a2, a3);
+create view v7 (b1) as select a1 from (select c1 from t1) dt (a1);
+create view v8 (b1, b2, b3) as select a1, a2, a3 from
+(
+select * from t1 union select * from t2 order by c1
+) as d3 (a1, a2, a3);
 # test parent query mergability
 explain format=json select a1 from v1;
 EXPLAIN
@@ -2156,6 +2165,31 @@ select * from v4 where e3 < 10;
 e1	e2	e3
 1	2	3
 4	5	6
+select * from v6;
+a1
+1
+4
+7
+10
+show create view v6;
+View	Create View	character_set_client	collation_connection
+v6	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v6` AS select `d3`.`a1` AS `a1` from (select `t1`.`c1` AS `a1`,`t1`.`c2` AS `a2`,`t1`.`c3` AS `a3` from `t1` union select `t2`.`c1` AS `c1`,`t2`.`c2` AS `c2`,`t2`.`c3` AS `c3` from `t2` order by `c1`) `d3`(`a1`,`a2`,`a3`)	latin1	latin1_swedish_ci
+select * from v7;
+b1
+1
+4
+show create view v7;
+View	Create View	character_set_client	collation_connection
+v7	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v7` AS select `dt`.`a1` AS `b1` from (select `t1`.`c1` AS `a1` from `t1`) `dt`(`a1`)	latin1	latin1_swedish_ci
+select * from v8;
+b1	b2	b3
+1	2	3
+4	5	6
+7	8	9
+10	11	12
+show create view v8;
+View	Create View	character_set_client	collation_connection
+v8	CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v8` AS select `d3`.`a1` AS `b1`,`d3`.`a2` AS `b2`,`d3`.`a3` AS `b3` from (select `t1`.`c1` AS `a1`,`t1`.`c2` AS `a2`,`t1`.`c3` AS `a3` from `t1` union select `t2`.`c1` AS `c1`,`t2`.`c2` AS `c2`,`t2`.`c3` AS `c3` from `t2` order by `c1`) `d3`(`a1`,`a2`,`a3`)	latin1	latin1_swedish_ci
 # show materialization and condition pushdown into having
 explain format=json select * from v4 where e3 < 10;
 EXPLAIN
@@ -3169,9 +3203,9 @@ EXPLAIN
 }
 # pushdown through GROUP BY
 create function f1(a int) returns int DETERMINISTIC return (a+1);
-create view v6 as select * from
+create view v9 as select * from
 (select c1, f1(c2), sum(c3) from t1 group by c1, f1(c2)) as f (c1, c2, c3);
-explain format=json select * from v6 where (c3+1) > 10 and c1 > 1 and c2 > 123;
+explain format=json select * from v9 where (c3+1) > 10 and c1 > 1 and c2 > 123;
 EXPLAIN
 {
   "query_block": {
@@ -5124,7 +5158,7 @@ where c1=d2 limit 1)
 alter table t1 rename column c1 to cc1;
 select * from v1;
 ERROR HY000: View 'test.v1' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them
-drop view v1, v2, v3, v4, v5, v6;
+drop view v1, v2, v3, v4, v5, v6, v7, v8, v9;
 drop table t1, t2, t3;
 create table t10 (a int);
 create table t20 (b int);
@@ -5148,14 +5182,14 @@ select * from v20;
 c	x	u1	y1	b2
 1	X	U	Y	1
 3	NULL	NULL	NULL	NULL
-select * from v20 limit 9;
+select * from v20  order by c limit 9;
 c	x	u1	y1	b2
 1	X	U	Y	1
 3	NULL	NULL	NULL	NULL
-select * from v21;
+select * from v21 order by c;
 c	x	u1	b1
-3	NULL	NULL	NULL
 1	X	U	1
+3	NULL	NULL	NULL
 drop view v10, v20, v11, v21;
 drop table t10, t20, t30;
 #

mysql-test/main/derived.test

@@ -1640,6 +1640,15 @@ create view v5 as select * from
     select c1, c2, sum(c3) as s from t2 group by c1, c2 having s > 3
   )
   as d2 (f1, f2, f3);
+create view v6 as select a1 from
+  (
+    select * from t1 union select * from t2 order by c1
+  ) as d3 (a1, a2, a3);
+create view v7 (b1) as select a1 from (select c1 from t1) dt (a1);
+create view v8 (b1, b2, b3) as select a1, a2, a3 from
+  (
+    select * from t1 union select * from t2 order by c1
+  ) as d3 (a1, a2, a3);
 
 --echo # test parent query mergability
 --source include/explain-no-costs.inc
@@ -1655,6 +1664,12 @@ select a1, a2 from v1 union select b1, b2 from v2;
 select * from v1 union select * from v2;
 select * from v3 intersect select * from v2 union select * from v1;
 select * from v4 where e3 < 10;
+select * from v6;
+show create view v6;
+select * from v7;
+show create view v7;
+select * from v8;
+show create view v8;
 --echo # show materialization and condition pushdown into having
 --source include/explain-no-costs.inc
 explain format=json select * from v4 where e3 < 10;
@@ -1814,9 +1829,9 @@ explain format=json select * from v1 where if( a1 regexp 'def', 'foo', a2 )
 
 --echo # pushdown through GROUP BY
 create function f1(a int) returns int DETERMINISTIC return (a+1);
-create view v6 as select * from
+create view v9 as select * from
   (select c1, f1(c2), sum(c3) from t1 group by c1, f1(c2)) as f (c1, c2, c3);
-explain format=json select * from v6 where (c3+1) > 10 and c1 > 1 and c2 > 123;
+explain format=json select * from v9 where (c3+1) > 10 and c1 > 1 and c2 > 123;
 drop function f1;
 
 --echo # name resolution for multi select units
@@ -2057,7 +2072,7 @@ alter table t1 rename column c1 to cc1;
 --error ER_VIEW_INVALID
 select * from v1;
 
-drop view v1, v2, v3, v4, v5, v6;
+drop view v1, v2, v3, v4, v5, v6, v7, v8, v9;
 drop table t1, t2, t3;
 
 # test derived embedded in views
@@ -2080,8 +2095,8 @@ create view v21 as select * from t30
   left join (select 'X' as x, v11.u, v11.b1 from v11) dt2 (x, u1, b1)
   on t30.c=dt2.b1 order by x;
 select * from v20;
-select * from v20 limit 9;
-select * from v21;
+select * from v20  order by c limit 9;
+select * from v21 order by c;
 drop view v10, v20, v11, v21;
 drop table t10, t20, t30;
 

sql/sql_derived.cc

@@ -1354,7 +1354,7 @@ bool mysql_derived_reinit(THD *thd, LEX *lex, TABLE_LIST *derived)
                        derived->get_unit()));
   st_select_lex_unit *unit= derived->get_unit();
 
-  if (derived->original_names_are_saved)
+  if (derived->original_names_source)
     unit->first_select()->set_item_list_names(derived->original_names);
 
   // reset item names to that saved after wildcard expansion in JOIN::prepare

sql/sql_view.cc

@@ -662,6 +662,19 @@ bool mysql_create_view(THD *thd, TABLE_LIST *views,
   }
 #endif
 
+  /*
+    Reset item list names within derived tables so that when reparsed in the
+    view, references elsewhere within this select_lex can be correctly resolved
+  */
+  for (SELECT_LEX *sl= lex->all_selects_list; sl; sl= sl->next_select_in_list())
+  {
+    for (TABLE_LIST *tl= sl->get_table_list(); tl && !res; tl= tl->next_local)
+    {
+      if (tl->original_names_source)
+        tl->original_names_source->set_item_list_names(tl->original_names);
+    }
+  }
+
   res= mysql_register_view(thd, &ddl_log_state, view, mode, backup_file_name);
 
   /*

sql/table.cc

@@ -10336,7 +10336,7 @@ bool TABLE_LIST::save_original_names(st_select_lex *derived)
 {
   if (unlikely(derived->with_wild))
     return false;
-  if (original_names_are_saved)
+  if (original_names_source)
     return false;
 
   // these elements allocated in LEX::parsed_derived_table
@@ -10356,7 +10356,7 @@ bool TABLE_LIST::save_original_names(st_select_lex *derived)
          (original_name= overwrite_iterator++))
     lex_string_set( original_name, item_list_element->name.str);
 
-  original_names_are_saved= true;
+  original_names_source= derived;
   return false;
 }
 

sql/table.h

@@ -2640,7 +2640,7 @@ struct TABLE_LIST
   With_element *with;          /* With element defining this table (if any) */
   List<Lex_ident_sys>   *column_names;  /* list of correlation column names */
   List<Lex_ident_sys>   *original_names;/* list of original column names    */
-  bool original_names_are_saved:1;
+  st_select_lex         *original_names_source;
   bool save_original_names(st_select_lex *derived);
 
   /* Bitmap of the defining with element */