do not try to use equal field from outer query as field of local join (BUG#6384)

mysql-test/r/subselect.result:
  changes in plans
  test for bug#6384
mysql-test/t/subselect.test:
  test for bug#6384
sql/sql_select.cc:
  do not set equal field from outer query

mysql-test/r/subselect.result

@@ -333,7 +333,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	DEPENDENT SUBQUERY	t7	eq_ref	PRIMARY	PRIMARY	4	test.t6.clinic_uq	1	Using index
 Warnings:
 Note	1276	Field or reference 'clinic_uq' of SELECT #2 was resolved in SELECT #1
-Note	1003	select `test`.`t6`.`patient_uq` AS `patient_uq`,`test`.`t6`.`clinic_uq` AS `clinic_uq` from `test`.`t6` where exists(select 1 AS `Not_used` from `test`.`t7` where (`test`.`t6`.`clinic_uq` = `test`.`t7`.`uq`))
+Note	1003	select `test`.`t6`.`patient_uq` AS `patient_uq`,`test`.`t6`.`clinic_uq` AS `clinic_uq` from `test`.`t6` where exists(select 1 AS `Not_used` from `test`.`t7` where (`test`.`t7`.`uq` = `test`.`t6`.`clinic_uq`))
 select * from t1 where a= (select a from t2,t4 where t2.b=t4.b);
 ERROR 23000: Column 'a' in field list is ambiguous
 drop table t1,t2,t3;
@@ -1744,7 +1744,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	DEPENDENT SUBQUERY	t1	eq_ref	PRIMARY	PRIMARY	4	test.tt.id	1	Using where; Using index
 Warnings:
 Note	1276	Field or reference 'tt.id' of SELECT #2 was resolved in SELECT #1
-Note	1003	select `test`.`tt`.`id` AS `id`,`test`.`tt`.`text` AS `text` from `test`.`t1` `tt` where not(exists(select `test`.`t1`.`id` AS `id` from `test`.`t1` where ((`test`.`t1`.`id` < 8) and (`test`.`tt`.`id` = `test`.`t1`.`id`)) having (`test`.`t1`.`id` is not null)))
+Note	1003	select `test`.`tt`.`id` AS `id`,`test`.`tt`.`text` AS `text` from `test`.`t1` `tt` where not(exists(select `test`.`t1`.`id` AS `id` from `test`.`t1` where ((`test`.`t1`.`id` < 8) and (`test`.`t1`.`id` = `test`.`tt`.`id`)) having (`test`.`t1`.`id` is not null)))
 insert into t1 (id, text) values (1000, 'text1000'), (1001, 'text1001');
 create table t2 (id int not null, text varchar(20) not null default '', primary key (id));
 insert into t2 (id, text) values (1, 'text1'), (2, 'text2'), (3, 'text3'), (4, 'text4'), (5, 'text5'), (6, 'text6'), (7, 'text7'), (8, 'text8'), (9, 'text9'), (10, 'text10'), (11, 'text1'), (12, 'text2'), (13, 'text3'), (14, 'text4'), (15, 'text5'), (16, 'text6'), (17, 'text7'), (18, 'text8'), (19, 'text9'), (20, 'text10'),(21, 'text1'), (22, 'text2'), (23, 'text3'), (24, 'text4'), (25, 'text5'), (26, 'text6'), (27, 'text7'), (28, 'text8'), (29, 'text9'), (30, 'text10'), (31, 'text1'), (32, 'text2'), (33, 'text3'), (34, 'text4'), (35, 'text5'), (36, 'text6'), (37, 'text7'), (38, 'text8'), (39, 'text9'), (40, 'text10'), (41, 'text1'), (42, 'text2'), (43, 'text3'), (44, 'text4'), (45, 'text5'), (46, 'text6'), (47, 'text7'), (48, 'text8'), (49, 'text9'), (50, 'text10');
@@ -2272,7 +2272,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	DEPENDENT SUBQUERY	t1	ALL	NULL	NULL	NULL	NULL	2	Using where
 Warnings:
 Note	1276	Field or reference 'up.a' of SELECT #2 was resolved in SELECT #1
-Note	1003	select `test`.`up`.`a` AS `a`,`test`.`up`.`b` AS `b` from `test`.`t1` `up` where exists(select 1 AS `Not_used` from `test`.`t1` where (`test`.`up`.`a` = `test`.`t1`.`a`))
+Note	1003	select `test`.`up`.`a` AS `a`,`test`.`up`.`b` AS `b` from `test`.`t1` `up` where exists(select 1 AS `Not_used` from `test`.`t1` where (`test`.`t1`.`a` = `test`.`up`.`a`))
 drop table t1;
 CREATE TABLE t1 (t1_a int);
 INSERT INTO t1 VALUES (1);

mysql-test/t/subselect.test

@@ -1777,7 +1777,6 @@ DROP TABLE t1,t2;
 #
 # Test for bug #9516: wrong evaluation of not_null_tables attribute in SQ 
 #
-
 CREATE TABLE t1 ( c1 integer );
 INSERT INTO t1 VALUES ( 1 );
 INSERT INTO t1 VALUES ( 2 );
@@ -1822,3 +1821,18 @@ CREATE TABLE `t2` (
 INSERT INTO `t2` VALUES (1, 1, 1, '10.10.10.1');
 SELECT s.ip, count( e.itemid ) FROM `t1` e JOIN t2 s ON s.sessionid = e.sessionid WHERE e.sessionid = ( SELECT sessionid FROM t2 ORDER BY sessionid DESC LIMIT 1 ) GROUP BY s.ip HAVING count( e.itemid ) >0 LIMIT 0 , 30;
 drop tables t1,t2;
+
+#
+# Correct building of equal fields list (do not include outer
+# fields) (BUG#6384)
+#
+CREATE TABLE t1 (EMPNUM   CHAR(3));
+CREATE TABLE t2 (EMPNUM   CHAR(3) );
+INSERT INTO t1 VALUES ('E1');
+INSERT INTO t2 VALUES ('E1');
+DELETE FROM t1
+WHERE t1.EMPNUM NOT IN
+      (SELECT t2.EMPNUM
+       FROM t2
+       WHERE t1.EMPNUM = t2.EMPNUM);
+DROP TABLE t1,t2;

sql/sql_select.cc

@@ -6381,7 +6381,9 @@ static bool check_equality(Item *item, COND_EQUAL *cond_equal)
     Item *left_item= ((Item_func*) item)->arguments()[0];
     Item *right_item= ((Item_func*) item)->arguments()[1];
     if (left_item->type() == Item::FIELD_ITEM &&
-        right_item->type() == Item::FIELD_ITEM)
+        right_item->type() == Item::FIELD_ITEM &&
+        !((Item_field*)left_item)->depended_from &&
+        !((Item_field*)right_item)->depended_from)
     {
       /* The predicate the form field1=field2 is processed */
 
@@ -6460,13 +6462,15 @@ static bool check_equality(Item *item, COND_EQUAL *cond_equal)
       /* The predicate of the form field=const/const=field is processed */
       Item *const_item= 0;
       Item_field *field_item= 0;
-      if (left_item->type() == Item::FIELD_ITEM && 
+      if (left_item->type() == Item::FIELD_ITEM &&
+          !((Item_field*)left_item)->depended_from &&
           right_item->const_item())
       {
         field_item= (Item_field*) left_item;
         const_item= right_item;
       }
-      else if (right_item->type() == Item::FIELD_ITEM && 
+      else if (right_item->type() == Item::FIELD_ITEM &&
+               !((Item_field*)right_item)->depended_from &&
                left_item->const_item())
       {
         field_item= (Item_field*) right_item;