Bug #118322 Result of `show master status` is not correct !!!

• Submitted: 1 Jun 4:47
• Reporter: Eric Sun
• Status: Open
• Category: MySQL Server: Replication
• Severity: S2 (Serious)
• Version: 8.0.20
• OS: Any
• Assigned to: MySQL Verification Team
• CPU Architecture: x86
• Tags: binlog, replication

[1 Jun 4:47] Eric Sun

Description:
When I test large transaction by sysbench.
--------------------------------------------------------------
| binlog.000031 | 961964090 | xxx        |                  | 360b55f2-01c4-11f0-8c7c-6e4f425f1652:1-420941769,
f1433e82-ce72-11ef-b3be-f19619bc62b8:1-27 |

Terminal 1
--------------------------------------------------------------
set autocommit=0;
update sbtest1 set c=reverse(c),pad=reverse(pad);
....
update sbtest8 set c=reverse(c),pad=reverse(pad);
....
---->  commit;

Terminal 2
--------------------------------------------------------------
show master status;
.... BLOCKED

# When COMMIT done, the result display like below:

| binlog.000031 | 8987608155 | xxx        |                  | 360b55f2-01c4-11f0-8c7c-6e4f425f1652:1-420941769,
f1433e82-ce72-11ef-b3be-f19619bc62b8:1-27 |

show master status;
# The result is correct, and I repeat query it again, the result display like below:

| binlog.000032 |      196 | xxx        |                  | 360b55f2-01c4-11f0-8c7c-6e4f425f1652:1-420941770,
f1433e82-ce72-11ef-b3be-f19619bc62b8:1-27 |

How to repeat:
Firstly, record the result `show master status`
Secondly, mock large transaction like Description
Finally, execute `show master status` more one times and check the result

Suggested fix:
This bug will affect Replication.