Flags, expunge, move, copy and folder deletion each existed twice: once for IMAP
(FlagRepository, ExpungeRepository, CopyRepository) and once for the webmail
(WebmailRepository). They kept the cached numbers true on their own and drifted:
- reading a message over IMAP never moved the folder's unread counter
- deleting in the webmail, or deleting a folder, never gave the quota back
- an IMAP expunge could push a counter below zero
MailStore now holds each state change once, in one transaction, with the same
rules everywhere: counters never go negative, a change that alters what a client
can observe raises the folder's modseq (one that alters nothing does not), the
quota follows the bytes, and a message is located by folder. The four repositories
are thin adapters that only translate how each path names a message.
The contract test added before this change (which failed on 8 of its cases)
now passes, as does the full suite.
Lucas Rayan
caf52c0225