Bug #33133: Views are not transparent

When resolving references we need to take into consideration
the view "fields" and allow qualified access to them.
Fixed by extending the reference resolution to process view
fields correctly.

mysql-test/r/func_group.result

@@ -1407,4 +1407,16 @@ SELECT COUNT(*), a FROM t1;
 COUNT(*)	a
 4	1
 DROP TABLE t1;
+set SQL_MODE=ONLY_FULL_GROUP_BY;
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3),(4);
+CREATE VIEW v1 AS SELECT a,(a + 1) AS y FROM t1;
+EXPLAIN EXTENDED SELECT y FROM v1 GROUP BY v1.y;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	Using temporary; Using filesort
+Warnings:
+Note	1003	select (`test`.`t1`.`a` + 1) AS `y` from `test`.`t1` group by (`test`.`t1`.`a` + 1)
+DROP VIEW v1;
+DROP TABLE t1;
+SET SQL_MODE=DEFAULT;
 End of 5.0 tests

mysql-test/t/func_group.test

@@ -901,5 +901,20 @@ SELECT COUNT(*), a FROM t1;
 
 DROP TABLE t1;
 
+#
+# Bug #33133: Views are not transparent
+#
+
+set SQL_MODE=ONLY_FULL_GROUP_BY;
+
+CREATE TABLE t1 (a INT);
+INSERT INTO t1 VALUES (1),(2),(3),(4);
+CREATE VIEW v1 AS SELECT a,(a + 1) AS y FROM t1;
+EXPLAIN EXTENDED SELECT y FROM v1 GROUP BY v1.y;
+
+DROP VIEW v1;
+DROP TABLE t1;
+SET SQL_MODE=DEFAULT;
+
 ###
 --echo End of 5.0 tests

sql/sql_base.cc

@@ -4256,6 +4256,35 @@ find_item_in_list(Item *find, List<Item> &items, uint *counter,
         break;
       }
     }
+    else if (table_name && item->type() == Item::REF_ITEM &&
+             ((Item_ref *)item)->ref_type() == Item_ref::VIEW_REF)
+    {
+      /*
+        TODO:Here we process prefixed view references only. What we should 
+        really do is process all types of Item_refs. But this will currently 
+        lead to a clash with the way references to outer SELECTs (from the 
+        HAVING clause) are handled in e.g. :
+        SELECT 1 FROM t1 AS t1_o GROUP BY a
+          HAVING (SELECT t1_o.a FROM t1 AS t1_i GROUP BY t1_i.a LIMIT 1).
+        Processing all Item_refs here will cause t1_o.a to resolve to itself.
+        We still need to process the special case of Item_direct_view_ref 
+        because in the context of views they have the same meaning as 
+        Item_field for tables.
+      */
+      Item_ident *item_ref= (Item_ident *) item;
+      if (item_ref->name && item_ref->table_name &&
+          !my_strcasecmp(system_charset_info, item_ref->name, field_name) &&
+          !my_strcasecmp(table_alias_charset, item_ref->table_name,
+                         table_name) &&
+          (!db_name || (item_ref->db_name && 
+                        !strcmp (item_ref->db_name, db_name))))
+      {
+        found= li.ref();
+        *counter= i;
+        *resolution= RESOLVED_IGNORING_ALIAS;
+        break;
+      }
+    }
   }
   if (!found)
   {