BUG#923246: Loosescan reports different result than other semijoin methods

- If LooseScan is used with quick select, require that quick select produces 
  data in key order (this disables use of MRR, which can return data in arbitrary order).

1 files changed, 40 insertions, 0 deletions

diff --git a/mysql-test/r/subselect_sj_jcl6.result b/mysql-test/r/subselect_sj_jcl6.result
index a27b6b7b55d..dd358ced14a 100644
--- a/mysql-test/r/subselect_sj_jcl6.result
+++ b/mysql-test/r/subselect_sj_jcl6.result
@@ -2602,6 +2602,46 @@ k	8	v
 g	0	j
 g	8	v
 DROP TABLE t1, t2;
+#
+# BUG#923246: Loosescan reports different result than other semijoin methods
+#
+set @tmp_923246= @@optimizer_switch;
+set optimizer_switch='mrr=on,materialization=off';
+create table t0 (a int);
+insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t1 (kp1 int, kp2 int, c int, filler char(100), key(kp1, kp2));
+insert into t1 select A.a+10*(B.a+10*C.a), 0, 0, 'filler' from t0 A, t0 B, t0 C;
+insert into t1 select * from t1 where kp1 < 20;
+create table t3 (a int);
+insert into t3 select A.a + 10*B.a from t0 A, t0 B;
+select * from t3 where a in (select kp1 from t1 where kp1<20);
+a
+0
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+11
+12
+13
+14
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+19
+explain select * from t3 where a in (select kp1 from t1 where kp1<20);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	range	kp1	kp1	5	NULL	48	Using where; Using index; LooseScan
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	100	Using where; Using join buffer (flat, BNL join)
+drop table t0,t1,t3;
+set optimizer_switch= @tmp_923246;
 set optimizer_switch=@subselect_sj_tmp;
 #
 # BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off