IndexMerge cached wrong plan

[ChenPeng2013]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

drop table IDT_MULTI15840STROBJSTROBJ;
CREATE TABLE `IDT_MULTI15840STROBJSTROBJ` (
  `COL1` enum('aa', 'zzz') DEFAULT NULL,
  `COL2` smallint(6) DEFAULT NULL,
  `COL3` date DEFAULT NULL,
  KEY `U_M_COL4` (`COL1`,`COL2`),
  KEY `U_M_COL5` (`COL3`,`COL2`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;
INSERT INTO `IDT_MULTI15840STROBJSTROBJ` VALUES ('zzz',1047,'6115-06-05'),('zzz',-23221,'4250-09-03'),('zzz',27138,'1568-07-30'),('zzz',-30903,'6753-08-21'),('zzz',-26875,'6117-10-10');


prepare stmt from 'select * from IDT_MULTI15840STROBJSTROBJ where col3 <=> ? or col1 in (?, ?, ?) and col2 not between ? and ?;';
set @a="0051-12-23", @b="none", @c="none", @d="none", @e=-32757, @f=-32757;
execute stmt using @a,@b,@c,@d,@e,@f;
set @a="9795-01-10", @b="aa", @c="aa", @d="aa", @e=31928, @f=31928;
execute stmt using @a,@b,@c,@d,@e,@f;

2. What did you expect to see? (Required)

MySQL [test]> set @a="9795-01-10", @b="aa", @c="aa", @d="aa", @e=31928, @f=31928;
Query OK, 0 rows affected (0.00 sec)

MySQL [test]> execute stmt using @a,@b,@c,@d,@e,@f;
Empty set (0.00 sec)

3. What did you see instead (Required)

mysql> execute stmt using @a,@b,@c,@d,@e,@f;
+------+--------+------------+
| COL1 | COL2   | COL3       |
+------+--------+------------+
| zzz  |   1047 | 6115-06-05 |
| zzz  | -23221 | 4250-09-03 |
| zzz  |  27138 | 1568-07-30 |
| zzz  | -30903 | 6753-08-21 |
| zzz  | -26875 | 6117-10-10 |
+------+--------+------------+
5 rows in set (0.05 sec)

4. What is your TiDB version? (Required)

Release Version: v6.7.0-alpha-146-g96e345d1b
Edition: Community
Git Commit Hash: 96e345d1b3b88e0fb46d93d5117f666e353c9cf3
Git Branch: master
UTC Build Time: 2023-03-01 01:06:43
GoVersion: go1.19.1
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: unistore

[qw4990]

It is introduced by #41723, I'll fix it soon.