Change characters allowed in JOOMLA usernames

By default, Joomla does not allow certain characters to be used in usernames (e.g. hypens, brackets, square brackets etc.). This is done for good reasons, especially security. However, sometimes for different reasons, you will need to allow certain usernames. To change the characters allowed by Joomla you need to change the core code as described below.
We are simply removing the hyphen \- from the regular expression which searches for invalid characters.


File: includes/joomla.php

From:

if (eregi( "[\<|\>|\"|\'|\%|\;|\(|\)|\&|\+|\-]", $this->username) || strlen( $this->username ) < 3) {
$this->_error = sprintf( addslashes( _VALID_AZ09 ), addslashes( _PROMPT_UNAME ), 2 );
return false;
}

To:
if (eregi( "[\<|\>|\"|\'|\%|\;|\(|\)|\&|\+]", $this->username) || strlen( $this->username ) < 3) {
$this->_error = sprintf( addslashes( _VALID_AZ09 ), addslashes( _PROMPT_UNAME ), 2 );
return false;
}


File: components/com_user/user.html.php

From:
var r = new RegExp("[\<|\>|\"|\'|\%|\;|\(|\)|\&|\+|\-]", "i");

To
var r = new RegExp("[\<|\>|\"|\'|\%|\;|\(|\)|\&|\+]", "i");


File: administrator/components/com_user/admin.users.html.php

From:
var r = new RegExp("[\<|\>|\"|\'|\%|\;|\(|\)|\&|\+|\-]", "i");

To:
var r = new RegExp("[\<|\>|\"|\'|\%|\;|\(|\)|\&|\+]", "i");

That's it. You should now be able to register a new user with a hyphen.