869319 - [email/IMAP] properly support and add test coverage for UIDVALIDITY rolls

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: Gaia::E-Mail, defect)

Description

[Andrew Sutherland [:asuth] (he/him)]

The IMAP sync implementation currently does not care about UIDVALIDITY.  This is not a great idea but does not have the lethal impact it would have on a client like Thunderbird which is UID-centric.  Our mails are characterized first by their INTERNALDATE and secondly by their UID, so synchronization will recover from a roll.

The major correctness risk of the current implementation is that our mutation operations only care about UID, so in the event a UIDVALIDITY roll leaves us with any overlap between the pre-roll UIDs and the post-roll UIDs, mutations will be incorrect and potentially data-lossy depending on what the mutation is.  Such operations could exist because the operation was enqueued prior to the roll or because the user is operating in an offline mode and scrolls to messages that have not yet been synchronized out of existence.

This was not dealt with sooner because a fake server is required to meaningfully test this and UIDVALIDITY rolls are less common on recent-ish IMAP servers, but mainly for time/prioritization reasons.

Comment 1

[BMO Automation]

Firefox OS is not being worked on