wrong result when optimize order by for index

[wjhuang2016]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t(a char(10), b char(10), c char(10), index (a, b, c)) collate utf8mb4_bin;
insert into t values ("b", "a", "1"), ("b", "A", "2"), ("c", "a", "3");
set names utf8mb4 collate utf8mb4_general_ci;
select * from t where (a>"a" and b="a") or (b = "A" and a < "d") order by a,c;

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

+------+------+------+
| a    | b    | c    |
+------+------+------+
| b    | a    | 1    |
| b    | A    | 2    |
| c    | a    | 3    |
+------+------+------+

3. What did you see instead (Required)

mysql> select * from t where (a>"a" and b="a") or (b = "A" and a < "d") order by a,c;
+------+------+------+
| a    | b    | c    |
+------+------+------+
| b    | A    | 2    |
| b    | a    | 1    |
| c    | a    | 3    |
+------+------+------+
3 rows in set (0.00 sec)

4. What is your TiDB version? (Required)

master

[xuyifangreeneyes]

/label affects-5.2

[xuyifangreeneyes]

/label affects-5.3

[github-actions]

Please check whether the issue should be labeled with 'affects-x.y' or 'fixes-x.y.z', and then remove 'needs-more-info' label.