This question already has an answer here:
Consider the following two sentences:
(A) The man or woman has not been born yet whom I would trust to write error-free English.
(B) The man or woman has not been born yet who would trust me to write error-free English.
In sentence (A), a nonexistent person is the subject of "has" and the object of "trust" in the relative clause, which begins with "whom". In sentence (B), our ghost is the subject of both the initial clause and the relative clause, which begins with "who". In (A), I am the subject of trust, whereas I am the object of it in (B)—hence the use of "me".
Since "trust" has the force to change "I" to "me" in (B), I believe it should also have the force to change "who" to "whom" in (A). Am I right or wrong, and why? Should a contact clause be used in (B) instead, and if so, why?
EDIT: Having accepted the correct answer, I was right about "whom" being used in (A), but "who" could also be used in (A), in everyday speech and writing (informal contexts). The answer to my second question about the contact clause is probably no for (B) but yes for (A)! With a contact clause sentence (A) would read: "The man or woman has not been born yet I would trust to write error-free English." The relative pronoun can be removed in (A) because it's not the subject.
As a side note, I consider both relative clauses (A) and (B) to be defining relative clauses, because even though the relative clause deals with a non-existent subject, the relative clause still restricts the meaning of the first clause, thusly defining it via negativity (as similarly happens in a sentence like, "The Stack Exchange website has not been created yet within which every answer is not a million times better than any answer given to any question on Yahoo Answers.").