Merge mysql.com:/home/psergey/mysql-4.1-bug8711

into mysql.com:/home/psergey/mysql-5.0-bug8711

mysql-test/r/join_outer.result

@@ -677,6 +677,26 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	2	
 drop table t1, t2, t3;
 create table t1 (
+a int(11),
+b char(10),
+key (a)
+);
+insert into t1 (a) values (1),(2),(3),(4);
+create table t2 (a int);
+select * from t1 left join t2 on t1.a=t2.a where not (t2.a <=> t1.a);
+a	b	a
+1	NULL	NULL
+2	NULL	NULL
+3	NULL	NULL
+4	NULL	NULL
+select * from t1 left join t2 on t1.a=t2.a having not (t2.a <=> t1.a);
+a	b	a
+1	NULL	NULL
+2	NULL	NULL
+3	NULL	NULL
+4	NULL	NULL
+drop table t1,t2;
+create table t1 (
 match_id tinyint(3) unsigned not null auto_increment,
 home tinyint(3) unsigned default '0',
 unique key match_id (match_id),

mysql-test/t/join_outer.test

@@ -457,6 +457,19 @@ explain select * from t1 left join t2  on  b1 = a1 left join t3  on  c1 = a1  an
 
 drop table t1, t2, t3;
 
+# Test for BUG#8711 '<=>' was considered to be a NULL-rejecting predicate.
+create table t1 (
+  a int(11),
+  b char(10),
+  key (a)
+);
+insert into t1 (a) values (1),(2),(3),(4);
+create table t2 (a int);
+
+select * from t1 left join t2 on t1.a=t2.a where not (t2.a <=> t1.a);
+select * from t1 left join t2 on t1.a=t2.a having not (t2.a <=> t1.a);
+drop table t1,t2;
+
 # Test for BUG#5088
 
 create table t1 (

sql/item_cmpfunc.h

@@ -323,6 +323,7 @@ public:
   Item_func_equal(Item *a,Item *b) :Item_bool_rowready_func2(a,b) {};
   longlong val_int();
   void fix_length_and_dec();
+  table_map not_null_tables() const { return 0; }
   enum Functype functype() const { return EQUAL_FUNC; }
   enum Functype rev_functype() const { return EQUAL_FUNC; }
   cond_result eq_cmp_result() const { return COND_TRUE; }