This incorporates much better duplicate detection in the local database, using both RFC-822 Message-ID as well as IMAP metadata (internaldate, RFC822 size) to determine if a message is already stored in the database. Very useful when a message is stored in multiple folders, or an already-downloaded message is returned to a folder it originated in (i.e. INBOX).
Also some minor fixes to listing email by EmailIdentifier which save a roundtrip to the server for certain edge cases.
Conversations now fully monitor the Folder for both additions and removals of messages.
This exposed a couple of bugs in the database code, which are fixed here as well. I also
used this opportunity to clean up some of the internal Conversations code, simplifying Node
management. #4333 will be a big boost here when implemented.
addressing.
Positional addressing is a nightmare for a lot of reasons, especially keeping positions
up-to-date as the Folder mutates. Now, positions are returned with the email but for
advisory reasons only, and do not keep up-to-date. It is expected that a client will use
positional addressing to "bootstrap" the application's data store, then use EmailIdentifier
addressing to traverse the Folder's contents.
Prior commit did not completely fix the problem in the case where a remote folder open took
a long time. This bulletproofs the solution, but does mean that there will be some
situations where FAST messages return with EmailLocations that radically change in the near
future. As the contract allows for any changes whatsoever, this is acceptable.
