Wrong enum calculation result in where condition.

[wshwsh12]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

drop table t;
create table t(e enum('a','','b'));
insert into t values(1),(2),(3);
select * from t where e;

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

MySQL [test]> select * from t where e;
+------+
| e    |
+------+
| a    |
|      |
| b    |
+------+
3 rows in set (0.000 sec)

3. What did you see instead (Required)

[tidb]> select * from t where e;
+------+
| e    |
+------+
| a    |
| b    |
+------+
2 rows in set (0.001 sec)

4. What is your TiDB version? (Required)

17a65ab

[wshwsh12]

https://github.com/pingcap/tidb/blob/master/expression/expression.go#L462 We should check Enum valuse, not Enum name.len. @ichn-hu PTAL

[ichn-hu]

https://github.com/pingcap/tidb/blob/master/expression/expression.go#L462 We should check Enum valuse, not Enum name.len. @ichn-hu PTAL

Yeah... But I am currently on calling, I might only be available responding after the new year vacation

[ti-srebot]

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5. Affected versions

[v4.0.0:v4.0.10],[v5.0.0-rc]

6. Fixed versions

master