recover expression index cause data inconsistency

[xiongjiwei]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t(a int, index idx((a+1)));
insert into t values (1);
insert into t values (2);
admin recover index t idx;
admin check table t;

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

3. What did you see instead (Required)

mysql> create table t(a int, index idx((a+1)));
Query OK, 0 rows affected (0.04 sec)

mysql> insert into t values (1);
Query OK, 1 row affected (0.00 sec)

mysql> insert into t values (2);
Query OK, 1 row affected (0.00 sec)

mysql> admin recover index t idx;
+-------------+------------+
| ADDED_COUNT | SCAN_COUNT |
+-------------+------------+
|           2 |          2 |
+-------------+------------+
1 row in set (0.01 sec)

mysql> admin check table t;
ERROR 8134 (HY000): data inconsistency in table: t, index: idx, col: _V$_idx_0, handle: "1", index-values:"KindNull <nil>" != record-values:"KindInt64 2", compare err:<nil>

4. What is your TiDB version? (Required)

mysql> select tidb_version();
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()
                                                                                                         |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v6.5.0-2-gf700b565bc
Edition: Community
Git Commit Hash: f700b565bcf1115f27fab076f7183cf9d78a0f16
Git Branch: release-6.5
UTC Build Time: 2023-01-09 09:47:14
GoVersion: go1.19.1
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: unistore |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.02 sec)

I believe it happens since expression index is supported