You, who

Hello, Gurus and Members!!

1. The two sentences below, a is with a comma, and b is not.

a. He will give freedom to you, who are struggling to get out of the darkness.
b. He will give freedom to you who are struggling to get out of the darkness.

Both are unacceptable?
Or both acceptable?
Or only b. is acceptable?

Interestingly, Google doesn't show any result of "you, who".

2. Huddleston and Pullum say that the below is unacceptable, but they don’t give any specific reason. Is there any reason?

*John came into the room, who looked just like Uncle Oswald.

Below is from Huddleston and Pullum, just for the reference.

Postposing of relative clause
It is also possible, however, for the relative clause to occur in postposed position, at the
end of the clause containing its antecedent.

[22]
i A stranger came into the room who looked just like Uncle Oswald.
ii Kim lent a book to Ed which contained all the information he needed.
iii I met a man the other day who says he knows you.
iv There was a fighJ reported in Monday's paper that put three people in hospital.

This construction is most likely when the informational content of the relative clause is
greater than that of the material that would follow it in the matrix clause if it occupied the default position following the antecedent.'3 It will generally be avoided if it would result in possible confusion as to what was the intended antecedent. Compare [iJ, for example, with A man was talking to one of the check-out operators who looked just like Uncle Oswald, where one of the check-out operators provides a more salient antecedent than man. And She put a hat on her head that had corks hanging from it too strongly evokes the picture of the head having corks hanging from it to be used with hat as intended antecedent. Postposed relative clauses are predominantly of the integrated type. For example, [22i] becomes quite unacceptable if we replace a stranger by a proper name, which would require the relative to be supplementary: *John came into the room, who looked just like Uncle Oswald. Nevertheless, postposed supplementary relatives do sometimes
occur:
[23]
i Only the flower is used, which is not poisonous and is attached to the plant with a
very fine stem.
ii She could hear her father in the next room, who was angrily complaining about the
horrific telephone bill.