query reports "strconv.Atoi: parsing "M": invalid syntax"

[wjhuang2016]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

DROP TABLE IF EXISTS t1, t2;
CREATE TABLE t1 (c1 tinytext);
CREATE TABLE t2 (c2 datetime);
INSERT INTO t1 VALUES ('2_2(M');
select c2 from t1 left join t2 on c1 = c2;

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

No error

3. What did you see instead (Required)

strconv.Atoi: parsing "M": invalid syntax

4. What is your TiDB version? (Required)

master

[tangenta]

I think it is not common to join an invalid string with a datetime. Changed the severity into "moderate".