Menu links are not being restored if their parent menu links are not stored in Features

I have a main menu which (inter alia) has has these menu links:

Root (node/467)
  - First child (node/468)
    - First granchild (node/469)
    - Second granchild (node/470)

I need to export menu link "First child" and its' children menu links, therefore I have a following export code in my MODULE.features.menu_links.inc:

/**
 * @file
 * menu_links.features.menu_links.inc
 */

/**
 * Implements hook_menu_default_menu_links().
 */
function MODULE_menu_default_menu_links() {
  $menu_links = array();
  
  // Exported menu link: main-menu_first-child:node/468
  $menu_links['main-menu_first-child:node/468'] = array(
    'menu_name' => 'main-menu',
    'link_path' => 'node/468',
    'link_title' => 'First child',
    'options' => array(
      // ... skip irrelevant menu link meta data here and after for readability sake
      'identifier' => 'main-menu_first-child:node/468',
    ),
    'parent_identifier' => 'main-menu_root:node/467',
  );
  // Exported menu link: main-menu_first-grandchild:node/469
  $menu_links['main-menu_first-grandchild:node/469'] = array(
    'menu_name' => 'main-menu',
    'link_path' => 'node/469',
    'link_title' => 'First grandchild',
    'options' => array(
      'identifier' => 'main-menu_first-grandchild:node/469',
    ),
    'parent_identifier' => 'main-menu_first-child:node/468',
  );
  // Exported menu link: main-menu_second-grandchild:node/470
  $menu_links['main-menu_second-grandchild:node/470'] = array(
    'menu_name' => 'main-menu',
    'link_path' => 'node/470',
    'link_title' => 'Second grandchild',
    'options' => array(
      'identifier' => 'main-menu_second-grandchild:node/470',
    ),
    'parent_identifier' => 'main-menu_first-child:node/468',
  );
  return $menu_links;
}

1. Expected behaviour: Upon feature revert menu links are created or updated with data from feature settings.

2. Current behaviour: Upon feature revert menu links are neither created nor updated.

3. Problem: In MODULE.features.menu_links.inc file I don't have the root menu link exported which is the parent menu link for exported $menu_links['main-menu_first-child:node/468'] menu link.

During menu link restoration process menu_links_features_revert() calls menu_links_features_rebuild() which eventually calls menu_links_features_rebuild_ordered().

menu_links_features_rebuild_ordered() function in features.menu.inc tries to order exported menu links depending on whether they have parent menu links defined.

// Line 288
$ordered = array();
// ...
foreach ($unordered as $key => $link) {
  $identifier = menu_links_features_identifier($link);
  $parent = isset($link['parent_identifier']) ? $link['parent_identifier'] : '';
  if (empty($parent)) {
    $ordered[$identifier] = 0;
    $all_links[$identifier] = $link;
    unset($unordered[$key]);
  }
  elseif (isset($ordered[$parent])) {
    $ordered[$identifier] = $ordered[$parent] + 1;
    $all_links[$identifier] = $link;
    unset($unordered[$key]);
  }
}
// .. $ordered contains links that are restored

In this case $menu_links['main-menu_first-child:node/468'] menu does not pass neither if (empty($parent)) nor elseif (isset($ordered[$parent])) test because it has parent identified defined and parent identifier is not defined in $ordered.

4. Solution: Set the weight (to make the order) of the menu links that don't have their parents menu links exported the same as if menu link didn't have parent menu link at all:

foreach ($unordered as $key => $link) {
  $identifier = menu_links_features_identifier($link);
  $parent = isset($link['parent_identifier']) ? $link['parent_identifier'] : '';
  $weight = 0;
  if (isset($ordered[$parent])) {
    $weight = $ordered[$parent] + 1;
  }
  $ordered[$identifier] = $weight;
  $all_links[$identifier] = $link;
  unset($unordered[$key]);
}

A patch against HEAD is attached.