get_language_from_request should not fallback to settings.LANGUAGE_CODE

[sergioisidoro]

I'm writing a middleware to fallback to a different language depending on the TLD of the domain of the HTTP_HOST

However, I noticed that get_language_from_request falls back to the settings default language, which will almost always take precedence in this case.

This is quite confusing, since settings.LANGUAGE_CODE is not "from the request", but from the application configuration, and it feels that the responsibility of falling back to the default language should lie in the Middleware, not in this function.

Solution / Summary: get_language_from_request should return None, to communicate to the middleware that there was no language from request, and that the middleware should fallback to the default. Otherwise if the get_language_from_request returns "EN" we don't know if "EN" is actually a request preference, or because it came from the default settings.LANGUAGE_CODE