No e-mail verification required autologin

The way that Drupal works means that while the module is correctly using the user hooks, you loss the ability to log in when the user name is changed as the auto login step uses the $form_state name value, and not the generated value.

This is a catch 22 situation, as you need to change this early to generate the emails, et al, but this blocks the login process.

My workaround was to add another user_register submit handler to do the authentication step after the hook_user register that is called by user_register_submit. It would be easy to include this feature in the module, but using this code you get full control of the message and redirect. (A string override is fairly easy to do via settings.php for the message itself, but the redirect would be a great feature if you add this to your module.)

<?php

function HOOK_form_alter(&$form, $form_state, $form_id) {
  switch ($form_id) {
    case 'user_register':
      $form['#submit'][] = 'custom_email_registration_name_submit';
      break;
  }
}

function custom_email_registration_name_submit($form, &$form_state) {
  if (!isset($form_state['user'])) {
    return;
  }

  $admin = user_access('administer users');
  $account = $form_state['user'];

  if (!variable_get('user_email_verification', TRUE) && $account->status && !$admin) {
    // No e-mail verification is required, create new user account, and login
    // user immediately.
    $auth = array(
      'pass' => $form_state['values']['pass'],
      'name' => $account->name,
    );
    if (user_authenticate($auth)) {
      // Authenticated, add a message and go to the users account
      // Since the standard workflow doesn't work, no other messages should appear.
      drupal_set_message(t('Registration successful. You are now logged in.'));
      $form_state['redirect'] = 'user/'. $account->uid;
    }
  }
}

?>