Authentication

Hi Iñaki

It is collation after all:

# php auth/ldap/auth_ldap_sync_users.php
Configuring temp table
Creating temp table mdl_extuser
Connecting to ldap...
	+ 835 users
Got 835 records from LDAP

Going to execute the following SQL sentence:
 SELECT e.username, e.username
                FROM mdl_extuser e LEFT JOIN mdl_user u ON e.username = u.username
                WHERE u.id IS NULL 
No users to be added

mysql> use moodle_test;
Database changed

mysql> SELECT e.username, e.username FROM mdl_extuser e LEFT JOIN mdl_user u ON e.username = u.username WHERE u.id IS NULL;
ERROR 1267 (HY000): Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '='

mysql> select COUNT(*) FROM mdl_extuser;
+----------+
| COUNT(*) |
+----------+
|      835 |
+----------+
1 row in set (0.00 sec)

My default collate is utf8_unicode_ci. Looks like the newly created mdl_extuser is "utf8_general_ci,IMPLICIT".

I went on and ran:

mysql> alter table `mdl_extuser` convert to character set utf8 collate utf8_unicode_ci;
mysql> SELECT e.username, e.username FROM mdl_extuser e LEFT JOIN mdl_user u ON e.username = u.username WHERE u.id IS NULL;
ERROR 1267 (HY000): Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '='

mysql> alter table `mdl_user` convert to character set utf8 collate utf8_unicode_ci;
mysql> SELECT e.username, e.username FROM mdl_extuser e LEFT JOIN mdl_user u ON e.username = u.username WHERE u.id IS NULL;
+---------------------------+---------------------------+
| username                  | username                  |
+---------------------------+---------------------------+
| firstname.lastname              | firstname.lastname               |
|...
+---------------------------+---------------------------+
835 rows in set (0.01 sec)

P.S. I'll gladly send you shell access and db password, if the process is easier for you that way.