Only show selected menu on menu_edit_item form.

When adding or editing a menu link starting form the menu_overview_form we go to the menu_edit_item form.
It's confusing and sometimes hard to explain why the Parent link dropdown shows all available menus when starting from a selected menu.
Wouldn't it be better to only show the selected menu?
There's an original_item array containing the selected menu name this could be used to alter the options array.

What's the reason to show all menus, because it could easily be done altering the $form['parent']['#options'] array.

/**
 * 
 * Implements hook_form_BASE_FORM_ID_alter().
 */
function duo_menu_form_menu_edit_item_alter(&$form, $form_state) {

  // Alter parent menu options in order to only show the selected menu
  // Menu has to be in an array because we want to use menu_parent_options function
  // The form array always has a original_item variable from which we can get the selected form name
  $duo_menus = array($form['original_item']['#value']['menu_name'] => $form['original_item']['#value']['menu_name']);
  // Generate a list of possible parents (not including this link or descendants).
  $duo_menu_options = menu_parent_options($duo_menus, 0);
  $form['parent']['#options'] = $duo_menu_options;	

}

Jurgen.