Undefined index map in field_ui_admin_menu_map() when clearing cache

This may be related to a few other bugs I saw in the queue about clearing the cache. This one in particular is a result of the map element not being present on the $menu_item. Dumping a quick dump of the menu item object, I saw four or five that were related to the media module (1.x). A quick isset seemed to supress the error without any different in behavior (I think):

        $menu_item = menu_get_item($bundle_info['admin']['real path']);
        if (isset($menu_item['map'])) {
          $access_arguments = menu_unserialize(serialize($access_arguments), $menu_item['map']);
        }

That of course leaves $access_arguments undefined for the next bit of code, but it seems like that would make it just continue anyway.

Here's a dump of those menu items:

Array
(
    [path] => admin/config/media/file-types/manage/%
    [load_functions] => Array
        (
            [5] => 
        )

    [to_arg_functions] => 
    [access_callback] => 0
    [access_arguments] => a:0:{}
    [page_callback] => file_entity_list_types_page
    [page_arguments] => a:0:{}
    [delivery_callback] => 
    [fit] => 62
    [number_parts] => 6
    [context] => 0
    [tab_parent] => 
    [tab_root] => admin/config/media/file-types/manage/%
    [title] => Manage file types
    [title_callback] => t
    [title_arguments] => 
    [theme_callback] => 
    [theme_arguments] => a:0:{}
    [type] => 6
    [description] => Manage files used on your site.
    [position] => 
    [weight] => 0
    [include_file] => sites/all/modules/media/file_entity/file_entity.admin.inc
    [href] => admin/config/media/file-types/manage/audio
    [tab_root_href] => admin/config/media/file-types/manage/audio
    [tab_parent_href] => 
    [options] => Array
        (
        )

    [access] => 
    [original_map] => Array
        (
            [0] => admin
            [1] => config
            [2] => media
            [3] => file-types
            [4] => manage
            [5] => audio
        )

)
Array
(
    [path] => admin/config/media/file-types/manage/%
    [load_functions] => Array
        (
            [5] => 
        )

    [to_arg_functions] => 
    [access_callback] => 0
    [access_arguments] => a:0:{}
    [page_callback] => file_entity_list_types_page
    [page_arguments] => a:0:{}
    [delivery_callback] => 
    [fit] => 62
    [number_parts] => 6
    [context] => 0
    [tab_parent] => 
    [tab_root] => admin/config/media/file-types/manage/%
    [title] => Manage file types
    [title_callback] => t
    [title_arguments] => 
    [theme_callback] => 
    [theme_arguments] => a:0:{}
    [type] => 6
    [description] => Manage files used on your site.
    [position] => 
    [weight] => 0
    [include_file] => sites/all/modules/media/file_entity/file_entity.admin.inc
    [href] => admin/config/media/file-types/manage/image
    [tab_root_href] => admin/config/media/file-types/manage/image
    [tab_parent_href] => 
    [options] => Array
        (
        )

    [access] => 
    [original_map] => Array
        (
            [0] => admin
            [1] => config
            [2] => media
            [3] => file-types
            [4] => manage
            [5] => image
        )

)
Array
(
    [path] => admin/config/media/file-types/manage/%
    [load_functions] => Array
        (
            [5] => 
        )

    [to_arg_functions] => 
    [access_callback] => 0
    [access_arguments] => a:0:{}
    [page_callback] => file_entity_list_types_page
    [page_arguments] => a:0:{}
    [delivery_callback] => 
    [fit] => 62
    [number_parts] => 6
    [context] => 0
    [tab_parent] => 
    [tab_root] => admin/config/media/file-types/manage/%
    [title] => Manage file types
    [title_callback] => t
    [title_arguments] => 
    [theme_callback] => 
    [theme_arguments] => a:0:{}
    [type] => 6
    [description] => Manage files used on your site.
    [position] => 
    [weight] => 0
    [include_file] => sites/all/modules/media/file_entity/file_entity.admin.inc
    [href] => admin/config/media/file-types/manage/video
    [tab_root_href] => admin/config/media/file-types/manage/video
    [tab_parent_href] => 
    [options] => Array
        (
        )

    [access] => 
    [original_map] => Array
        (
            [0] => admin
            [1] => config
            [2] => media
            [3] => file-types
            [4] => manage
            [5] => video
        )

)
Array
(
    [path] => admin/config/media/file-types/manage/%
    [load_functions] => Array
        (
            [5] => 
        )

    [to_arg_functions] => 
    [access_callback] => 0
    [access_arguments] => a:0:{}
    [page_callback] => file_entity_list_types_page
    [page_arguments] => a:0:{}
    [delivery_callback] => 
    [fit] => 62
    [number_parts] => 6
    [context] => 0
    [tab_parent] => 
    [tab_root] => admin/config/media/file-types/manage/%
    [title] => Manage file types
    [title_callback] => t
    [title_arguments] => 
    [theme_callback] => 
    [theme_arguments] => a:0:{}
    [type] => 6
    [description] => Manage files used on your site.
    [position] => 
    [weight] => 0
    [include_file] => sites/all/modules/media/file_entity/file_entity.admin.inc
    [href] => admin/config/media/file-types/manage/default
    [tab_root_href] => admin/config/media/file-types/manage/default
    [tab_parent_href] => 
    [options] => Array
        (
        )

    [access] => 
    [original_map] => Array
        (
            [0] => admin
            [1] => config
            [2] => media
            [3] => file-types
            [4] => manage
            [5] => default
        )

)