show create user doesn't give right response

[cyliu0]

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.

Create user with requirement, then show create user. On TiDB, no matter which method you required, show create user will not show it.

2. What did you expect to see?
   On MySQL

mysql> create user a;
Query OK, 0 rows affected (0.04 sec)

mysql> show create user a\G
*************************** 1. row ***************************
CREATE USER for a@%: CREATE USER 'a'@'%' IDENTIFIED WITH 'caching_sha2_password' REQUIRE NONE PASSWORD EXPIRE DEFAULT ACCOUNT UNLOCK PASSWORD HISTORY DEFAULT PASSWORD REUSE INTERVAL DEFAULT PASSWORD REQUIRE CURRENT DEFAULT
1 row in set (0.01 sec)

mysql> create user b require x509;
Query OK, 0 rows affected (0.01 sec)

mysql> show create user b\G
*************************** 1. row ***************************
CREATE USER for b@%: CREATE USER 'b'@'%' IDENTIFIED WITH 'caching_sha2_password' REQUIRE X509 PASSWORD EXPIRE DEFAULT ACCOUNT UNLOCK PASSWORD HISTORY DEFAULT PASSWORD REUSE INTERVAL DEFAULT PASSWORD REQUIRE CURRENT DEFAULT
1 row in set (0.00 sec)

3. What did you see instead?
   On TiDB

mysql> create user a;
Query OK, 0 rows affected (0.00 sec)

mysql> show create user a;
+-----------------------------------------------------------------------------------------------------------------------+
| CREATE USER for a@%                                                                                                   |
+-----------------------------------------------------------------------------------------------------------------------+
| CREATE USER 'a'@'%' IDENTIFIED WITH 'mysql_native_password' AS '' REQUIRE NONE PASSWORD EXPIRE DEFAULT ACCOUNT UNLOCK |
+-----------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> create user b require x509;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> show create user b;
+-----------------------------------------------------------------------------------------------------------------------+
| CREATE USER for b@%                                                                                                   |
+-----------------------------------------------------------------------------------------------------------------------+
| CREATE USER 'b'@'%' IDENTIFIED WITH 'mysql_native_password' AS '' REQUIRE NONE PASSWORD EXPIRE DEFAULT ACCOUNT UNLOCK |
+-----------------------------------------------------------------------------------------------------------------------+
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)?

mysql> select tidb_version()\G
*************************** 1. row ***************************
tidb_version(): Release Version: v4.0.0-alpha-360-gdab72fbd1-dirty
Git Commit Hash: dab72fbd16a5c5329d32cbafcb6f9aace3bdf10d
Git Branch: master
UTC Build Time: 2019-09-26 03:16:57
GoVersion: go version go1.12.9 darwin/amd64
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false
1 row in set (0.00 sec)

[kolbe]

Fixed by #13955