Notice on Create user page with admin if no providers enabled

Hi guys,

After installing the CSNA module, latest version at 8866f85, without enabling any other API providers or CSNA sub-modules, with the admin user, I browsed to create a new user at admin/people/create (by clicking the Add user link on the People admin page) and got the following error message:

Notice: Undefined variable: items in theme_csna_providers() (line 256 of /sites/default/modules/csna/csna.module). Backtrace:
theme_csna_providers(Array) theme.inc:1142
theme('csna_providers', Array) csna.module:162
csna_form_alter(Array, Array, 'user_register_form') module.inc:1056
drupal_alter(Array, Array, Array, 'user_register_form') form.inc:1085
drupal_prepare_form('user_register_form', Array, Array) form.inc:340
drupal_build_form('user_register_form', Array) form.inc:131
drupal_get_form('user_register_form') user.admin.inc:14
user_admin('create') 
call_user_func_array('user_admin', Array) menu.inc:517
menu_execute_active_handler() index.php:21

 
After taking a closer look at the code, as indicated in the error log message, it seems there is no proper handling in theme_csna_providers in case no providers are declared:
See csna.admin.inc, line 253:

<?php
function theme_csna_providers($providers) {
  foreach ($providers as $provider_id => $provider) {
    $items[] = l($provider['display_title'], 'csna/' . $provider_id, array('html' => TRUE));
  }
  return theme('item_list', array('items' => $items));
}
?>

If $providers is empty, then $items is undefined.

This would be fairly simple to solve for the time being by adding an initialization for $items:
$items = array();;
would pretty much do the trick to avoid the log error message.

However, this would maybe bring another feature request that should maybe be discussed in another ticket.

Would we really want to display the CSNA links on the Registration form (user_register_form), if it's the Create user form used by the administrator?
In short, would we need to display the CSNA links on the admin add user page as well? (It is also a user_register_form page).

I guess there would be several solutions for that, such as adding configuration settings to CSNA admin page to include or exclude certain form_ids, or simply choose to only display the links if user is anonymous, etc...
I would assume this could be further discussed in a different ticket, for the time being, we could try fixing the error log message with a simple and clean solution in code.

Please let me know if you would have any objections, questions, comments, recommendations, suggestions or issues on this bug report or on the feature request/idea, I would surely be glad to explain in more details.

Thanks very much for your feedback in advance.
Cheers!