MySQLでユーザーに設定したパスワードが効かなくて嵌った件

Amazon Linuxでyumを使ってMySQL56をインストールし起動し、データベースとユーザーを作成して
ログインしてみると設定したパスワードでログインできないではありませんか（；゜〇゜)

1. mysql> create database mydb character set utf8;  
2. mysql> grant all on mydb.* to user identified by 'xxxxx';  
3.   
4. $ mysql -u user -p  
5. Enter password:   
6. ERROR 1045 (28000): Access denied for user 'user '@'localhost' (using password: YES)  

mysql> create database mydb character set utf8;
mysql> grant all on mydb.* to user identified by 'xxxxx';

$ mysql -u user -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'user '@'localhost' (using password: YES)

ところが、パスワードなしでログインを試みるとは入れてしまいましたΣ(゜д゜;)

プロセスを確認してみると指定したユーザーでログインしています。

1. $ mysql -u user  
2. Welcome to the MySQL monitor.  Commands end with ; or \g.  
3. Your MySQL connection id is 30  
4. Server version: 5.6.35 MySQL Community Server (GPL)  
5.   
6. Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.  
7.   
8. Oracle is a registered trademark of Oracle Corporation and/or its  
9. affiliates. Other names may be trademarks of their respective  
10. owners.  
11.   
12. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.  
13.   
14. mysql> show processlist;  
15. +----+-----------+-----------+------+---------+------+-------+------------------+  
16. | Id | User  | Host      | db   | Command | Time | State | Info  |  
17. +----+-----------+-----------+------+---------+------+-------+------------------+  
18. | 28 | user      | localhost | NULL | Query   |    0 | init  | show processlist |  
19. +----+-----------+-----------+------+---------+------+-------+------------------+  
20. 1 row in set (0.00 sec)  

$ mysql -u user
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 30
Server version: 5.6.35 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show processlist;
+----+-----------+-----------+------+---------+------+-------+------------------+
| Id | User  | Host      | db   | Command | Time | State | Info  |
+----+-----------+-----------+------+---------+------+-------+------------------+
| 28 | user      | localhost | NULL | Query   |    0 | init  | show processlist |
+----+-----------+-----------+------+---------+------+-------+------------------+
1 row in set (0.00 sec)

ユーザーテーブルどーなってるか確認してみるとユーザー名なし、パスワードなしの登録が入っていました

あやしいです(；一_一)

1. mysql> select user,host from user;  
2. +-----------+------------------+-------------------------------------------+  
3. | user     | host        | password       |  
4. +-----------+------------------+-------------------------------------------+  
5. | user      | %         | *XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |  
6. | root     | 127.0.0.1        |                                           |  
7. | root     | ::1        |                                           |  
8. |     | ip-xxx-xx-xx-xxx |                                           |  
9. | root     | ip-xxx-xx-xx-xxx |                                           |  
10. |     | localhost        |                                           |  
11. | root     | localhost        |                                           |  
12. +-----------+------------------+-------------------------------------------+  
13.   
14. mysql> select host from user where user="";  
15. +------------------+  
16. | host     |  
17. +------------------+  
18. | ip-xxx-xx-xx-xxx |  
19. | localhost    |  
20. +------------------+  
21. 2 rows in set (0.00 sec)  

mysql> select user,host from user;
+-----------+------------------+-------------------------------------------+
| user     | host        | password       |
+-----------+------------------+-------------------------------------------+
| user      | %         | *XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |
| root     | 127.0.0.1        |                                           |
| root     | ::1        |                                           |
|     | ip-xxx-xx-xx-xxx |                                           |
| root     | ip-xxx-xx-xx-xxx |                                           |
|     | localhost        |                                           |
| root     | localhost        |                                           |
+-----------+------------------+-------------------------------------------+

mysql> select host from user where user="";
+------------------+
| host     |
+------------------+
| ip-xxx-xx-xx-xxx |
| localhost    |
+------------------+
2 rows in set (0.00 sec)

怪しいので消してしまいましょうヽ(´ー｀)/

1. mysql> delete from user where user="";  
2. Query OK, 2 rows affected (0.00 sec)  
3.   
4. mysql> FLUSH PRIVILEGES;  
5. Query OK, 0 rows affected (0.00 sec)  

mysql> delete from user where user="";
Query OK, 2 rows affected (0.00 sec)

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

そしたら、次の通り入れました！ヾ(*･∀･)ノ"

1. $ mysql -u user -p  
2. Enter password:   
3. Welcome to the MySQL monitor.  Commands end with ; or \g.  
4. Your MySQL connection id is 30  
5. Server version: 5.6.35 MySQL Community Server (GPL)  
6.   
7. Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.  
8.   
9. Oracle is a registered trademark of Oracle Corporation and/or its  
10. affiliates. Other names may be trademarks of their respective  
11. owners.  
12.   
13. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.  
14.   
15. mysql>   

$ mysql -u user -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 30
Server version: 5.6.35 MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>