added test for BUG#3759

mysql-test/r/select.result

@@ -2327,3 +2327,24 @@ select * from t2,t3 where t2.s = t3.s;
 s	s
 two		two	
 drop table t1, t2, t3;
+create table t1 (a integer,  b integer, index(a), index(b));
+create table t2 (c integer,  d integer, index(c), index(d));
+insert into t1 values (1,2), (2,2), (3,2), (4,2);
+insert into t2 values (1,3), (2,3), (3,4), (4,4);
+explain select * from t1 left join t2 on a=c where d in (4);
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t2	ref	c,d	d	5	const	2	Using where
+t1	ALL	a	NULL	NULL	NULL	3	Using where
+select * from t1 left join t2 on a=c where d in (4);
+a	b	c	d
+3	2	3	4
+4	2	4	4
+explain select * from t1 left join t2 on a=c where d = 4;
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t2	ref	c,d	d	5	const	2	Using where
+t1	ALL	a	NULL	NULL	NULL	3	Using where
+select * from t1 left join t2 on a=c where d = 4;
+a	b	c	d
+3	2	3	4
+4	2	4	4
+drop table t1, t2;

mysql-test/t/select.test

@@ -1874,3 +1874,17 @@ select * from t3 where s = 'one';
 select * from t1,t2 where t1.s = t2.s;
 select * from t2,t3 where t2.s = t3.s;
 drop table t1, t2, t3;
+
+#
+# Bug #3759
+# Both queries should produce identical plans and results.
+#
+create table t1 (a integer,  b integer, index(a), index(b));
+create table t2 (c integer,  d integer, index(c), index(d));
+insert into t1 values (1,2), (2,2), (3,2), (4,2);
+insert into t2 values (1,3), (2,3), (3,4), (4,4);
+explain select * from t1 left join t2 on a=c where d in (4);
+select * from t1 left join t2 on a=c where d in (4);
+explain select * from t1 left join t2 on a=c where d = 4;
+select * from t1 left join t2 on a=c where d = 4;
+drop table t1, t2;
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