Notices after deleting term

When I delete a term from a taxonomy that is attached to a taxonomy menu I get 2 different notices:

Notice: Undefined offset: -1 in _taxonomy_menu_create_item() (line 850 of .../taxonomy_menu/taxonomy_menu.module).

Notice: Trying to get property of non-object in _taxonomy_menu_create_item() (line 850 of .../taxonomy_menu/taxonomy_menu.module).

// Find the weight of the root taxonomy term; we'll need it in case we want
    // a flat taxonomy menu.
    if (is_object($term)) {
      $term_parents = taxonomy_get_parents_all($term->tid);
      $root_term_weight = $term_parents[count($term_parents) - 1]->weight;
    }
    else {
      $root_term_weight = 0;
    }

This is all because $term_parents inside the if is an empty array (because it was deleted?).