Default state check overrides label wrongly

In registration_form() in registration.forms.inc:

  // Ensure default state is in options or it won't be set.
  if (!in_array($default_state->label, $states)) {
    $states[$default_state->name] = $default_state->label;
  }

First, that's a very strange way to see if an #option is set, because you're checking the labels, not the keys. Second, $default_state->label is not the right way to create the missing option's label, because it's different from registration_get_states_options().

It should do this:

  // Ensure default state is in options or it won't be set.
  if (!isset($states[$default_state->name])) {
    $states[$default_state->name] = t('@state', array('@state' => entity_label('registration_state', $default_state)));
  }

The t('@state') is very weird IMO, but the entity_label() is very important, because that's a custom translation moment for other modules.

Patch later.