let $engine_type= myisam;

--source include/partition_mrr.inc

--echo #
--echo # MDEV-21628: Index condition pushdown for a simple condition over 
--echo # index fields is not used for ref access of partitioned tables when employing BKA
--echo #

create table t0 (
tp int, a int, b int, c varchar(12), index idx (a,b)
);

insert into t0 values
(1,3,30,'yyzy'), (1,3,30,'yxxyy'), (1,3,30,'yyxy'), (1,3,30,'xxyy'),
(1,3,30,'yyxz'), (1,3,30,'yyzz'), (1,3,30,'xxyzy'), (1,3,30,'yyyy'),
(1,3,30,'yzzy'), (1,93,30,'zzzy'),
(2,3,40,'yxx'), (2,4,40,'xx'), (2,3,10,'zxz'),
(2,3,40,'yyx'), (2,4,40,'xxx'), (2,3,10,'zyyz'),
(2,3,40,'xzzzz'), (2,4,40,'yyyxx'), (2,3,10,'zyz'),
(2,3,40,'xxx'), (2,4,40,'xx'), (2,3,10,'zzz'),
(2,3,40,'yyxzx'), (2,4,40,'xyx'), (2,3,10,'xzz'),
(2,3,40,'xxxzz'), (2,4,40,'xxz'), (2,3,10,'zzzy'),
(2,3,40,'zzxxx'), (2,4,40,'zxx'), (2,3,10,'yzzz'),
(2,3,40,'xyyxx'), (2,4,40,'xzzzx'), (2,3,10,'zzxxz'),
(2,3,40,'yzxxx'), (2,4,40,'xxzy'), (2,3,10,'zzzyx'),
(2,93,40,'xzx'), (2,94,40,'xz'), (2,93,10,'zyyyz'),
(3,4,30,'yx'), (3,4,30,'yyxxx'), (3,4,30,'zzyy'), (3,4,30,'zxyy'),
(3,4,30,'xxyy'), (3,4,30,'yyzx'),  (3,4,30,'zyyy'), (3,4,30,'yzy'),
(3,4,30,'zzzyy'), (3,94,30,'yyz');
 
create table t1 (
tp int, a int, b int, c varchar(12), index idx (a,b)
) engine=myisam
partition by list (tp)
( partition p1 values in (1),
  partition p2 values in (2),
  partition p3 values in (3));
insert into t1 select * from t0;
 
create table t2 (a int, index idx(a)) engine=myisam;
insert into t2 values (1), (2), (3), (4), (5);
insert into t2 select a+10 from t2;
insert into t2 select a+20 from t2;

analyze table t0,t1,t2;

set @tmp1=@@join_cache_level, @tmp2=@@optimizer_switch;
set join_cache_level=6, optimizer_switch='mrr=on';

explain
select * from t0,t2 where t2.a in (3,4) and t0.a=t2.a and (t0.b / 10) = 4;

--echo # This will use "Using index condition(BKA)"
explain
select * from t1,t2 where t2.a in (3,4) and t1.a=t2.a and (t1.b / 10) = 4;

set join_cache_level=@tmp1, optimizer_switch=@tmp2;

drop table t0,t1,t2;