Review follow-ups:
- The old key of a copied remote-only entry, and the old directory of a
rename that copied one, are now deleted once the rename has committed.
A rename that fails after the copy leaves the source entry and its
object in place, plus an extra object at the new key.
- Every part of a multipart copy is conditioned on the ETag the copy
started from, so an object overwritten mid-copy fails the copy
instead of mixing versions.
- Both copy paths keep the source's server-side encryption settings.
- filer.remote.sync no longer deletes a key that a remote-only entry
holds by the time the delete event is processed: a file deleted and
then replaced by a remote-only rename has its content only there.
Alex Russell
937d9af4a5