MySQL Bugs: #69658: can not drop user that created by mysql_install

Bug #69658	can not drop user that created by mysql_install_db if hostname contains upper
Submitted:	3 Jul 2013 9:39	Modified:	3 Jul 2013 11:42
Reporter:	xiaobin lin (OCA)	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	MySQL Server: Security: Privileges	Severity:	S3 (Non-critical)
Version:	5.1+	OS:	Any
Assigned to:		CPU Architecture:	Any
Tags:	drop user, upper case

Description:
Using the normal step mysql_install_db --defaults-file=my.cnf

After MySQL started, there are two some default users. If the hostname contains upper case character, there will be two users named ''@'myHost', 'root'@'myHost'.

Both of them can not be drop by "drop user" command.

The reason is that when mysql_install_db, the records are insert into mysql.user by "insert" statement.

So the raw named are filled.

But when run "drop user 'root'@myHost'" command, the hostname are changed lower case in the server-side. So an error is raised. There is no way to drop this user. Though "delete from mysql.user " can manage it, but it is not a standard operation.

How to repeat:
As above

Suggested fix:

./share/mysql_system_tables_data.sql
change 
set @current_hostname= @@hostname;
to
set @current_hostname= lower(@@hostname);

Thank you for the bug report, duplicate of Bug #62255

Also, see Bug #62254