Granting `create temporary tables` to *.* should not take effect

[djshow832]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

mysql -h127.1 -uroot -P4000

mysql> create database tmpdb;
Query OK, 0 rows affected (0.01 sec)

mysql> drop user test_user;
Query OK, 0 rows affected (0.00 sec)

mysql> create user test_user;
Query OK, 0 rows affected (0.01 sec)

mysql> grant create temporary tables on *.* to test_user;
Query OK, 0 rows affected (0.01 sec)

mysql -h127.1 -utest_user -P4000

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| INFORMATION_SCHEMA |
+--------------------+
1 row in set (0.00 sec)

mysql> create temporary table tmpdb.tmp(id int);
Query OK, 0 rows affected (0.00 sec)

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

mysql -h127.1 -utest_user -Ac

mysql> create temporary table tmpdb.tmp(id int);
ERROR 1044 (42000): Access denied for user 'test_user'@'localhost' to database 'tmpdb'

3. What did you see instead (Required)

mysql -h127.1 -utest_user -P4000

mysql> create temporary table tmpdb.tmp(id int);
Query OK, 0 rows affected (0.00 sec)

4. What is your TiDB version? (Required)

master

[JayLZhou]

/assign

[JayLZhou]

/unassign

[tiancaiamao]

The description of this issue is not accurate.
The real bug is show databases, when root grant temporary table privilege to a user, that user should be able to see the databases by command 'show databases'

The create temporary table tmpdb.tmp(id int) behavior is correct, at least correct in the currect master 914e4ce