inconsistent case insensitive behaviour with GRANT and SET ROLE hostnames.

[ramanich1]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

drop user if exists u1@localhost;
drop role if exists r1@vilhelmina;
CREATE USER u1@localhost;
CREATE ROLE r1@vilhelmina;
GRANT r1@Vilhelmina TO u1@localhost;

--connect as u1/foo

SET ROLE r1@Vilhelmina;

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

mysql> SET ROLE r1@Vilhelmina;
Query OK, 0 rows affected (0.00 sec)

3. What did you see instead (Required)

mysql> SET ROLE r1@Vilhelmina;
ERROR 3530 (HY000): `r1`@`Vilhelmina` is not granted to u1@localhost

4. What is your TiDB version? (Required)

| Release Version: v6.0.0-alpha-62-g15ddcd085
Edition: Community
Git Commit Hash: 15ddcd085a8be0f97c1b5ce1e5397369c3061372
Git Branch: master
UTC Build Time: 2022-03-14 10:28:33
GoVersion: go1.17.2
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |

[xiongjiwei]

hi, @morgo can you please take a look?