Incorrect double validation for language tag in ApplyOptionsToTag

[gsathya]

In ApplyOptionsToTag,

4. If language is not undefined, then
       a. If language does not match the language production, throw a RangeError exception.
       b. If language matches the grandfathered production, throw a RangeError exception.

which means that language can not match a grandfathered production after this point.

Later in ApplyOptionsToTag,

 10. If language is not undefined,
        a. If tag matches the privateuse or grandfathered production,
            i. Set tag to language.
           ii. If tag matches the grandfathered production,
                1. Set tag to CanonicalizeLanguageTag(tag).

We've already checked to see if the language tag matches a grandfathered production in step 4. I don't see why we require another validation and canonicalization in steps 10. a. ii and 10. a. ii. 1

[jackhorton]

Also, step 3 says to match the language option against the RFC5646 language production, which does not include grandfathered tags. So 4.b can't be hit anyways?

EDIT 1:
Ah I see the issue here. the commit fixes the comment I just made, but the GitHub.io rendered version doesn't reflect the update.

Could we get a new rendering?

EDIT 2:
The commit is still in PR. I obviously need to go take a nap. Anyways, I await the resolution of this soon :)

[littledan]

The PR at #57 could help some, but I'm not landing it yet because of the concerns @anba raised; anyway, this might all be a lot simpler once we resolve #63

[littledan]

Fixed by #66 .