[Dovecot] rename() non-atomic on HFS? (was: Dovecot-1.1.15 panics)

[...] mv foo.tmp foo [...]

[...]

So, apparently HFS+'s rename() isn't really atomic after all..

Are you sure OS X's mv(1) simply calls rename(2)? Maybe some magic in mv(1) for ._xxx resource forks or directory hardlinks?