MDEV-37653: IS TRUE incorrectly converts outer join to inner

Include original submission test case

Author: DaveGosselin-MariaDB

mysql-test/main/join_outer.result

@@ -2924,6 +2924,9 @@ c0	c0
 select t1.c0, t0.c0 from t1 left join t0 on 0 where not (t0.c0 is false);
 c0	c0
 1	NULL
+select t1.c0, t0.c0 from t1 left join t0 on false where (false or ((t0.c0 is true) in (false)));
+c0	c0
+1	NULL
 drop table t0, t1;
 # end of 10.11 tests
 SET optimizer_switch=@org_optimizer_switch;

mysql-test/main/join_outer.test

@@ -2443,6 +2443,7 @@ insert into t1 values (1);
 insert into t0 values (1);
 select t1.c0, t0.c0 from t1 left join t0 on 0 where not (t0.c0 is true);
 select t1.c0, t0.c0 from t1 left join t0 on 0 where not (t0.c0 is false);
+select t1.c0, t0.c0 from t1 left join t0 on false where (false or ((t0.c0 is true) in (false)));
 drop table t0, t1;
 
 --echo # end of 10.11 tests

mysql-test/main/join_outer_jcl6.result

@@ -2931,6 +2931,9 @@ c0	c0
 select t1.c0, t0.c0 from t1 left join t0 on 0 where not (t0.c0 is false);
 c0	c0
 1	NULL
+select t1.c0, t0.c0 from t1 left join t0 on false where (false or ((t0.c0 is true) in (false)));
+c0	c0
+1	NULL
 drop table t0, t1;
 # end of 10.11 tests
 SET optimizer_switch=@org_optimizer_switch;