Greetings,

I'm building a new 1.1.x-series Dovecot installation, and I have a problem setting up compatibility namespaces intended to handle old client-side settings.

(See also: http://wiki.dovecot.org/Namespaces#head-0f3ab5ecab632eb517866c3508021e0605d5...)

I have produced a slightly cut-down example configuration which demonstrates the problem:

# dovecot -n # 1.1.3: /etc/dovecot/dovecot.conf protocols: imap imaps pop3 pop3s ssl_cert_file(default): /etc/ssl/certs/imap.pem ssl_cert_file(imap): /etc/ssl/certs/imap.pem ssl_cert_file(pop3): /etc/ssl/certs/pop.pem ssl_key_file(default): /etc/ssl/private/imap.key ssl_key_file(imap): /etc/ssl/private/imap.key ssl_key_file(pop3): /etc/ssl/private/pop.key disable_plaintext_auth(default): yes disable_plaintext_auth(imap): yes disable_plaintext_auth(pop3): no login_dir: /var/run/dovecot/login login_executable(default): /usr/lib/dovecot/imap-login login_executable(imap): /usr/lib/dovecot/imap-login login_executable(pop3): /usr/lib/dovecot/pop3-login login_max_processes_count: 1024 max_mail_processes: 32768 verbose_proctitle: yes first_valid_uid: 100 mail_privileged_group: mail mail_location: mbox:~/IMAP:INBOX=~/.email:INDEX=/data/dovecot-indexes/%1u/%u mmap_disable: yes mail_nfs_storage: yes mail_nfs_index: yes mail_executable(default): /usr/lib/dovecot/imap mail_executable(imap): /usr/lib/dovecot/imap mail_executable(pop3): /usr/lib/dovecot/pop3 mail_plugins(default): zlib quota imap_quota mail_plugins(imap): zlib quota imap_quota mail_plugins(pop3): mail_plugin_dir(default): /usr/lib/dovecot/modules/imap mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3 imap_client_workarounds(default): delay-newmail outlook-idle tb-extra-mailbox-sep imap_client_workarounds(imap): delay-newmail outlook-idle tb-extra-mailbox-sep imap_client_workarounds(pop3): pop3_uidl_format(default): %08Xu%08Xv pop3_uidl_format(imap): %08Xu%08Xv pop3_uidl_format(pop3): %08Xv%08Xu namespace: type: private separator: / inbox: yes list: yes subscriptions: yes namespace: type: private separator: / prefix: Mail/ location: mbox:~/Mail:INDEX=/data/dovecot-indexes/%1u/%u hidden: yes subscriptions: yes namespace: type: private separator: / prefix: ~/Mail/ location: mbox:~/Mail:INDEX=/data/dovecot-indexes/%1u/%u hidden: yes subscriptions: yes auth default: mechanisms: gssapi gss-spnego plain passdb: driver: pam userdb: driver: passwd plugin: quota: fs:Disk Quota

Given this configuration, a Thunderbird client using a folder prefix of Mail/ is successfully able to enumerate (and access) non-INBOX folders:

5 list "" "Mail/%"

• LIST (\Noselect \HasChildren) "/" "Mail/archive"^M
• LIST (\NoInferiors \UnMarked) "/" "Mail/Trash"^M 5 OK List completed.^M 6 list "" "Mail/%/%"
• LIST (\Noselect \HasChildren) "/" "Mail/archive/"^M
• LIST (\NoInferiors \UnMarked) "/" "Mail/archive/INBOX-2008-10"^M
• LIST (\NoInferiors \UnMarked) "/" "Mail/archive/INBOX-2008-09"^M [...] 6 OK List completed.^M 7 list "" "INBOX"
• LIST (\NoInferiors \UnMarked) "/" "INBOX"^M 7 OK List completed.^M 8 list "" "Mail/archive"
• LIST (\Noselect \HasChildren) "/" "Mail/archive"^M 8 OK List completed.^M

... Whereas a client using a folder prefix of ~/Mail/ is only able to see its INBOX:

5 list "" "~/Mail/%" 5 OK List completed.^M 6 list "" "~/Mail/%/%" 6 OK List completed.^M 7 list "" "INBOX"

• LIST (\NoInferiors \UnMarked) "/" "INBOX"^M 7 OK List completed.^M 8 create "~/Mail/Trash" 8 NO Mailbox exists.^M

Note that even though it was unable to execute a listing of the hidden namespace, it was clearly aware of it, and able to discover that the 'Trash' mailbox that Thunderbird automatically tries to create already existed in the underlying filesystem.

Through experimentation, it appears that Dovecot 1.1.x doesn't correctly handle namespaces that *begin* with the character '~'; using ~ in the middle of a prefix, e.g. "flibble~/Mail", worked as documented, leading me to suspect a bug in the ~-expansion handling of Dovecot.

(Dovecot 1.0.x worked as expected in this configuration.)

Unfortunately, an hg bisect run on recent Dovecot-1.1 versions didn't expose the offending commit that introduced this problem, so this bug (assuming it is a bug) was probably inadvertently introduced during the 1.1-development series.

Can anyone suggest where in the source tree I should start looking to correct this behaviour?

Cheers, David

David McBride <dwm@tastycake.net>