On 5-Jun-2010, at 05:35, Guus der Kinderen wrote:
> Again, the gateway will initiate a session on Romeo's behalf to the legacy
> domain. The legacy roster representation is obtained, which now includes
> Juliet only. A typical gateway representation will send out a roster-add
> suggestion for [email protected] to the XMPP client of Romeo.
> As this item already exists on the XMPP roster, it is silently ignored.
> Benvolio's representation however, is also still there. Unless the gateway
> has either direct access to Romeo's XMPP roster, or obtains somehow the delta
> of roster changes on the legacy domain since the last login that the gateway
> did (both are unlikely), there's no way that the gateway can determine that
> it should send out a Roster Item Deletion suggestion. Romeo's XMPP roster
> will continue to include both:
>
> [email protected]
> [email protected]
>
> Benvolio is still there, even though it was removed from the roster on the
> legacy domain.
This is a general issue with roster item exchange, but soluble. We have
our roster item exchange component cache it's latest suggestions in a database
so it can detect deletions from the legacy service. IOW, our server remembers
that it once sent out adds for both legacyjuliet and legacybenvolio. When romeo
logs in again, it sees that only legacyjuliet is in the current legacy roster,
but that it previously suggested an add for legacybenvolio, so now it should
suggest a removal.
-bjc
