Need advice: mailbox-based \Seen flag

[Boris Lytochkin]

Hello!

I need an advice in implementing per-mailbox \Seen flag (or 'shared'
\Seen flag in per-user basis).

For now I want to implement it this way:
1) add a new mailbox attribute, say 'sharedseen'
2) switch path for .seen file in imap/seen_*.c:seen_getpath() if
   'sharedseen' flag is set on mailbox.
3) changes in replication module?

So, setting 'sharedseen' attribute to mailbox will cause using
per-mailbox seen-file.

What are weak points of this implementation?
Is there more correct way to make per-mailbox \Seen flag?


-- 
Boris Lytochkin,
JCS e-port, Moscow