The warning message of incorrect datetime is corrupt.

[SunRunAway]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do?
   If possible, provide a recipe for reproducing the error.

SELECT ADDDATE('2008-01-34', -1);

2. What did you expect to see?

mysql> SELECT ADDDATE('2008-01-34', -1);
+---------------------------+
| ADDDATE('2008-01-34', -1) |
+---------------------------+
| NULL                      |
+---------------------------+
1 row in set, 1 warning (0.00 sec)

mysql> show warnings;
+---------+------+----------------------------------------+
| Level   | Code | Message                                |
+---------+------+----------------------------------------+
| Warning | 1292 | Incorrect datetime value: '2008-01-34' |
+---------+------+----------------------------------------+
1 row in set (0.00 sec)

3. What did you see instead?

mysql> SELECT ADDDATE('2008-01-34', -1);
+---------------------------+
| ADDDATE('2008-01-34', -1) |
+---------------------------+
| NULL                      |
+---------------------------+
1 row in set, 1 warning (0.00 sec)

mysql> show warnings;
+---------+------+-----------------------------------------+
| Level   | Code | Message                                 |
+---------+------+-----------------------------------------+
| Warning | 1292 | Incorrect datetime value: '%!s(int=34)' |
+---------+------+-----------------------------------------+
1 row in set (0.00 sec)

4. What version of TiDB are you using (tidb-server -V or run select tidb_version(); on TiDB)?
   651632e in master branch

[ono-yoko]

@SunRunAway I am interesting in this issue. I am filling a PR to fix it.