dovecot - Apr 2014 - Shared mailboxes not working with . dot namespace separator - values truncated in SQL

Hello,

I have Dovecot configured for multiple domains (usernames are user at
domain.tld) and I wanted to enable shared mailboxes.

But there is some problem - if I share a folder, other user can't see it.

In the log I foud:
>  Apr 22 19:21:02 veverka dovecot: imap(user at veverka.tld): Error:
Couldn't create namespace 'shared.' for user petr: userdb didn't
return a home directory, but location used it (%h):
maildir:%h/Maildir:INDEX=~/Maildir/shared/%%u
>  Apr 22 19:21:02 veverka dovecot: imap(user at veverka.tld): Error:
Couldn't create namespace 'shared.' for user emclient at veverka:
userdb didn't return a home directory, but location used it (%h):
maildir:%h/Maildir:INDEX=~/Maildir/shared/%%u
Which is weird because the user name is "petr.surname" not only
"petr" and the domain is "veverka.tld" not only
"veverka".

So I turned on SQL logging on my PostgreSQL and saw that Dovecot executes these
queries:
>  2014-04-22 19:21:02 CEST LOG:  statement: SELECT * FROM dovecot_uzivatel
WHERE login = 'petr' AND domena = ''
>  2014-04-22 19:21:02 CEST LOG:  statement: SELECT * FROM dovecot_uzivatel
WHERE login = 'emclient' AND domena = 'veverka'
The first username was "petr.surname at veverka.tld" and the second
one was "emclient at veverka.tld" so it seems that it was truncated
right after first "." dot and I afraid that this is a bug.
Then it is obvious that Dovecot can't find the home directory and complains
in log (as mentioned above).

I found workaround ? I had "." configured as namespace separator so I
reconfigured it to "/" slash and now mailbox sharing works!
But I think that it should work also with "." dot separator and the
values should not be truncated in SQL queries.
I tried also using '%u' in my SQL and its value was also truncated.

Values in "dovecot-acl" a "shared-mailboxes" files seem to
be ok.

BTW: I have also another server with only one domain and simple user names (no
dots) and there the mailbox sharing works ?  but now it seems that it works only
accidentally. This might lead to hardly debuggable problems if someone has
usernames with and without dots ? mailbox sharing will work for some users but
for some not.

My old configuration:
> password_query = SELECT * FROM dovecot_heslo WHERE login = '%n' AND
domena = '%d'
> user_query = SELECT * FROM dovecot_uzivatel WHERE login = '%n' AND
domena = '%d'
> iterate_query = SELECT login AS username, domena AS domain FROM
dovecot_uzivatel
>  namespace {
>    type = shared
>    separator = .
>    prefix = shared.%%u.
>    location = maildir:%h/Maildir:INDEX=~/Maildir/shared/%%u
>    subscriptions = yes
>    list = children
>  }
Had to be reconfigured to:
>    separator = /
>    prefix = shared/%%u/
Used version:
> # dovecot --version
> 2.1.7
> # uname -a
> Linux veverka 3.11.0-19-generic #33-Ubuntu SMP Tue Mar 11 18:48:34 UTC 2014
x86_64 x86_64 x86_64 GNU/Linux
Regards,
Franta

P.S. If you have similar problem and have to switch from "." to
"/" separators, don't forget to update your Sieve scripts (with
fileinto). And sometimes also reconfiguration of the client is needed (e.g.
NGImap4ConnectionStringSeparator in SOGo; and Kontact/KMail stopped working and
I had to recreate the account in this client).

P.P.S. Iwas thinking about this again and it is probably not possible to support
this combination: dot separator + shared mailboxes + usernames with dots
(including the domain part).

So I suggest update in the wiki:
> n.b. If you have dots "." in your usernames (like `name.surname`
or `name at example.com`) it is not possible to use dot as a
[[Namespaces|namespace separator]]. Don't forget to use `separator = /` in
such cases.
on http://master.wiki2.dovecot.org/SharedMailboxes/Shared