Reference to field in outer subelect fixed

Fixed context in error mesages


mysql-test/r/subselect.result:
  tests of references and error message
mysql-test/t/subselect.test:
  tests of references and error message
sql/item.cc:
  Fixed layout
  Resolving field names of outer select
sql/item_subselect.cc:
  saving/restoring context for error messages
sql/mysql_priv.h:
  changed function interface to allow resolving field names inside Item_ref::fix_fields
sql/sql_base.cc:
  changed function interface to allow resolving field names inside Item_ref::fix_fields
sql/sql_lex.h:
  allow access to thd field

mysql-test/r/subselect.result

@@ -17,6 +17,16 @@ SELECT (SELECT 1),MAX(1) FROM (SELECT 1);
 1	1
 SELECT (SELECT a) as a;
 Reference 'a' not supported (forward reference in item list)
+EXPLAIN SELECT 1 FROM (SELECT 1 as a) HAVING (SELECT a)=1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	1	
+3	DEPENDENT SUBSELECT								No tables used
+2	DERIVED								No tables used
+SELECT 1 FROM (SELECT 1 as a) HAVING (SELECT a)=1;
+1
+1
+SELECT (SELECT 1), a;
+Unknown column 'a' in 'field list'
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8;
 create table t1 (a int);
 create table t2 (a int, b int);

mysql-test/t/subselect.test

@@ -8,6 +8,10 @@ SELECT (SELECT 1 FROM (SELECT 1) HAVING b=1) as a,(SELECT 1 FROM (SELECT 1) HAVI
 SELECT (SELECT 1),MAX(1) FROM (SELECT 1);
 -- error 1245
 SELECT (SELECT a) as a;
+EXPLAIN SELECT 1 FROM (SELECT 1 as a) HAVING (SELECT a)=1;
+SELECT 1 FROM (SELECT 1 as a) HAVING (SELECT a)=1;
+-- error 1054
+SELECT (SELECT 1), a;
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8;
 create table t1 (a int);
 create table t2 (a int, b int);

sql/item.cc

@@ -468,7 +468,7 @@ bool Item_field::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
 					 (last= sl)->get_table_list(),
 					 0)) != not_found_field)
 	    break;
-	  if((refer= find_item_in_list(this, (last= sl)->item_list,
+	  if ((refer= find_item_in_list(this, sl->item_list,
 				       REPORT_EXCEPT_NOT_FOUND)) !=
 	     (Item **)not_found_item)
 	    break;
@@ -867,6 +867,7 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference)
 				  REPORT_ALL_ERRORS))) ==
 	(Item **)not_found_item)
     {
+      Field *tmp= (Field*) not_found_field;
       /*
 	We can't find table field in table list of current select,
 	consequently we have to find it in outer subselect(s).
@@ -878,16 +879,21 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference)
       */
       SELECT_LEX *last=0;
       for ( ; sl ; sl= sl->outer_select())
-	if((ref= find_item_in_list(this, (last= sl)->item_list,
+      {
+	if ((ref= find_item_in_list(this, (last= sl)->item_list,
 				   REPORT_EXCEPT_NOT_FOUND)) !=
 	   (Item **)not_found_item)
 	  break;
+	if ((tmp= find_field_in_tables(thd, this,
+				       sl->get_table_list(),
+				       0)) != not_found_field);
+      }
 
       if (!ref)
-      {
 	return 1;
-      }
-      else if (ref == (Item **)not_found_item)
+      else if (!tmp)
+	return -1;
+      else if (ref == (Item **)not_found_item && tmp == not_found_field)
       {
 	// Call to report error
 	find_item_in_list(this,
@@ -896,6 +902,16 @@ bool Item_ref::fix_fields(THD *thd,TABLE_LIST *tables, Item **reference)
         ref= 0;
 	return 1;
       }
+      else if (tmp != not_found_field)
+      {
+	ref= 0; // To prevent "delete *ref;" on ~Item_erf() of this item
+	Item_field* f;
+	if (!((*reference)= f= new Item_field(tmp)))
+	  return 1;
+	f->depended_from= last;
+	thd->lex.current_select->mark_as_dependent(last);
+	return 0;
+      }
       else
       {
 	depended_from= last;

sql/item_subselect.cc

@@ -81,6 +81,7 @@ void Item_subselect::make_field (Send_field *tmp_field)
 
 bool Item_subselect::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
 {
+  char const *save_where= thd->where;
   int res= engine->prepare();
   if (!res)
   {
@@ -93,6 +94,7 @@ bool Item_subselect::fix_fields(THD *thd, TABLE_LIST *tables, Item **ref)
     fix_length_and_dec();
   }
   fixed= 1;
+  thd->where= save_where;
   return res;
 }
 
@@ -312,11 +314,13 @@ void subselect_union_engine::fix_length_and_dec()
 int subselect_single_select_engine::exec()
 {
   DBUG_ENTER("subselect_single_select_engine::exec");
+  char const *save_where= join->thd->where;
   if (!optimized)
   {
     optimized=1;
     if (join->optimize())
     {
+      join->thd->where= save_where;
       executed= 1;
       DBUG_RETURN(join->error?join->error:1);
     }
@@ -324,7 +328,10 @@ int subselect_single_select_engine::exec()
   if (select_lex->dependent && executed)
   {
     if (join->reinit())
+    {
+      join->thd->where= save_where;
       DBUG_RETURN(1);
+    }
     item->assign_null();
     item->assigned((executed= 0));
   }
@@ -335,14 +342,19 @@ int subselect_single_select_engine::exec()
     join->exec();
     join->thd->lex.current_select= save_select;
     executed= 1;
+    join->thd->where= save_where;
     DBUG_RETURN(join->error||thd->fatal_error);
   }
+  join->thd->where= save_where;
   DBUG_RETURN(0);
 }
 
 int subselect_union_engine::exec()
 {
-  return unit->exec();
+  char const *save_where= unit->thd->where;
+  int res= unit->exec();
+  unit->thd->where= save_where;
+  return res;
 }
 
 uint subselect_single_select_engine::cols()

sql/mysql_priv.h

@@ -463,7 +463,7 @@ bool table_is_used(TABLE *table, bool wait_for_name_lock);
 bool drop_locked_tables(THD *thd,const char *db, const char *table_name);
 void abort_locked_tables(THD *thd,const char *db, const char *table_name);
 extern const Field *not_found_field;
-Field *find_field_in_tables(THD *thd, Item_field *item, TABLE_LIST *tables,
+Field *find_field_in_tables(THD *thd, Item_ident *item, TABLE_LIST *tables,
 			    bool report_error);
 Field *find_field_in_table(THD *thd,TABLE *table,const char *name,uint length,
 			   bool check_grant,bool allow_rowid);

sql/sql_base.cc

@@ -1861,7 +1861,7 @@ const Field *not_found_field= (Field*) 0x1;
 */
 
 Field *
-find_field_in_tables(THD *thd, Item_field *item, TABLE_LIST *tables,
+find_field_in_tables(THD *thd, Item_ident *item, TABLE_LIST *tables,
 		     bool report_error)
 {
   Field *found=0;

sql/sql_lex.h

@@ -294,6 +294,7 @@ public:
   int cleanup();
   
   friend void mysql_init_query(THD *thd);
+  friend int subselect_union_engine::exec();
 private:
   bool create_total_list_n_last_return(THD *thd, st_lex *lex,
 				       TABLE_LIST ***result);