Contrary to what the documentation [1] says, AUTH_LOGIN_CHECK handlers do not get the do action passed. The action field of the passed data hash is always empty. This behavior has to reasons:
1. The $ACT global is not brought into the current scope via “global $ACT;” before creating the event data [2].
2. The event is fired (through including inc/auth.php [3]) before the $ACT global has been set at all [4].
I suggest to remove the parameter from the event data anyway, since this value should be accessed through $ACT if needed. To allow this, we should set this param (and probably others) before starting to fire events, i. e. before including inc/auth.php. See attached patch.
[1]
http://www.dokuwiki.org/devel:event:auth_login_check
[2]
http://dev.splitbrain.org/darcsweb/darcsweb.cgi?r=dokuwiki;a=headblob;f=/inc/auth.php#l84
[3]
http://dev.splitbrain.org/darcsweb/darcsweb.cgi?r=dokuwiki;a=headblob;f=/doku.php#l17
[4]
http://dev.splitbrain.org/darcsweb/darcsweb.cgi?r=dokuwiki;a=headblob;f=/doku.php#l25