[Mediawiki-l] Intercepting Usersname in $_POST for Special:Userlogin

[Michael B Allen]

Hello,

I have an AuthPlugin with which users may enter a username with a
domain component like:

  EXAMPLE\alice
or
  alice at example.com

I am trying to find a way for our plugin to canonicalize these names.
Is there a hook or somewhere that I can canonicalize usernames?

Setting the nickname in AuthPlugin::updateUser has no effect. Setting
$user->mName directly does not work because of logic at the top of
SpecialUserLogin::authenticateUserData that runs before
AuthPlugin::authenticate.

How does one do this?

Mike