Problem with active class in multi language Navigation

For menu items defined in the config.toml, we do matching on URLs for IsMenuCurrent etc., so for multilingual sites I guess you will have to define the full URL path, so:

[[languages.en.menu.main]]
    name = "About"
    weight = 2
    identifier = "about"
    url = "/en/about/"

And then just:

 <option value="{{ .URL  }}"

This will be simpler in the next Hugo version, where you can add front matter to the home and section pages etc.