P2-[4.0 Bug Hunting]-[SQL parser]-wrong error returned when missing alias

[sre-bot]

Bug Hunter issue tidb-challenge-program/bug-hunting-issue#98

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Bug Report

1. What did you do?

mysql> create table t4 (id int); 
Query OK, 0 rows affected (0.00 sec)   

mysql> select * from (select * from t4);
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your TiDB version for the right syntax to use line 1 column 32 near ""

2. What did you expect to see?

mysql>  select * from (select * from t4);
ERROR 1248 (42000): Every derived table must have its own alias

3. What did you see instead?

Error in syntax;

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

Master branch:

commit 8369ffd500f3fb235d8b584ac4298b2e59d8db55 (HEAD -> master, origin/master, origin/HEAD)
Author: Soup <[email protected]>
Date:   Tue May 26 15:38:29 2020 +0800

mysql> select tidb_version();
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                           |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: None
Edition: None
Git Commit Hash: None
Git Branch: None
UTC Build Time: None
GoVersion: go1.13.4
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

[zimulala]

PTAL @kennytm

[wjhuang2016]

Fixed by #19102

[ti-srebot]

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