Surely Quirrelmort wouldn't give Harry that diary, right?

I thought it was fairly obviously that diary, and thus an effort by Quirrelmort to take over/destroy Harry the way Ginny was (almost) in canon. Harry has apparently avoided the trap entirely because he is under the logically reasonable impression that he needs to learn Latin to read Roger Bacon's diary. I'm pretty sure other people have reached the same conclusion in previous threads.

We then see a second effort to approximately the same end with the Dementor brought on school grounds (at Quirrelmort's instigation) with Harry's wand "accidentally" being left near the cage.