txn: the update could not read the latest data if read committed is used.

[cfzjywxk]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

init
set global tidb_txn_mode = 'pessimistic';
set global tx_isolation = 'READ-COMMITTED';
create table t(a int key, b int);

session 1
begin pessimistic;

session 2
insert into t values(5, 5);

session 1
update t set b = 22 where a = 5;

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

mysql> update t set b = 22 where a = 5;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

3. What did you see instead (Required)

mysql> update t set b = 22 where a = 5;
Query OK, 0 rows affected (0.00 sec)
Rows matched: 0  Changed: 0  Warnings: 0

The update could not read the latest data, this is possibly a bug introduced during the refactoring of the transaction module in tidb, after #34702 the bug is fixed, but v6.1.x and v6.0.0 are affected.

4. What is your TiDB version? (Required)

tidb v6.0.0 v6.1.x

[jackysp]

I think 07b0c7c introduces this bug.

[cfzjywxk]

close by #41590