Use better breadcrumbs

In the example I made, there is a match on the parent menu after tracing back three levels; maybe that is too far to be known as parent menu.

I am not sure of what I said about the parent key; I thought I read something, maybe in the source code, but I am not able to find any reference to that anymore.

Taking as example a real case, Drupal core has a admin/settings/actions menu with "Home › Administer › Site configuration" like breadcrumb, and a admin/settings/actions/configure/b1500c08f3b29d92a795c5e60736b613 menu with "Home › Administer › Site configuration › Actions" like breadcrumb.
Looking at the definition of the menus given by system.module, the first menu matches the admin/settings/actions item in the array returned by system_menu(), while the second one matches the admin/settings/actions/manage item.

In the example I made when I opened this issue, maybe it's enough to change the menu to admin/rules/rules/rules_default_rule_1/edit/1/condition to avoid that the breadcrumb becomes "Home".

I finally found out where I read of the parent key used in the array declaring the menu items.
The search.module uses the following code:

  foreach (module_implements('search') as $name) {
    $items['search/'. $name .'/%menu_tail'] = array(
      'title callback' => 'module_invoke',
      'title arguments' => array($name, 'search', 'name', TRUE),
      'page callback' => 'search_view',
      'page arguments' => array($name),
      'access callback' => '_search_menu',
      'access arguments' => array($name),
      'type' => MENU_LOCAL_TASK,
      'parent' => 'search',
      'file' => 'search.pages.inc',
    );
  }

I don't have any reason to think this is a specific case valid for search.module, so I would think that is the way to have a coherent breadcrumb.