Subscriptions and sieve filters lost after upgrade to Cyrus 3.0

[Martin Svec]

Hello,

after upgrade from Cyrus 2.5.7 to 3.0.6, we noticed that some users lost their IMAP subscriptions
and all sieve filters. After some investigation, we've found that this happens if the user's name
contains dot(s). For sieve directories and .sub files, version 2.5.x uses names with dots replaced
with "^". But 3.0.x series expects the names with dots.

Note that we've altnamespace and unixhierarchysep turned _on_ in both versions, so no namespace
transformations should be needed.

Names in 2.5.x:
/var/imap/sieve/domain/s/somedomain.com/n/name^with^dots/defaultbc
/var/imap/domain/s/somedomain.com/user/n/name^with^dots.sub

Names in 3.0.x:
/var/imap/sieve/domain/s/somedomain.com/n/name.with.dots/defaultbc
/var/imap/domain/s/somedomain.com/user/n/name.with.dots.sub

Surprisingly, other metadata files like .lock files and quota files still use the format with "^"
characters.

I've found no information regarding this incompatible change in 3.0 upgrade documentation. Is this
an expected behavior or a bug?

Best regards

Martin Svec