[Dovecot] lazy_expunge and shared folders

[Florian]

Hi,

since migration to Dovecot 2.2 I have troubles with lazy_expunge as soon as 
a user shares a folder. The user the folder is shared to cannot login 
anymore, dovecot logs Fatal: lazy_expunge: Unknown namespace: '.EXPUNGED/'

- When no folder is shared lazy_expunge is working fine, deleted mails are 
moved to the expunged namespace and can be recovered without any problems.
- Sharing folders works as long as I disable lazy_expunge.

I have used the config (with minor changes) with dovecot 2.0 for years 
without any problem. Switching to dovecot 2.2.10 (atrps repository) or 
2.2.12 (dovecot enterprise repo) lazy_expunge and acl do not work together 
anymore.

Is it a bug, a known limitation or is something wrong with my config?
Any hints are welcome.

Thanks in advance,
Florian

dovecot -n

# 2.2.12.12 (03196f188677): /etc/dovecot/dovecot.conf
# OS: Linux 2.6.32-042stab085.20 x86_64 CentOS release 6.5 (Final) 
auth_cache_negative_ttl = 10 mins
auth_cache_size = 10 M
auth_cache_ttl = 2 hours
auth_failure_delay = 10 secs
auth_mechanisms = plain login
auth_socket_path = /var/run/dovecot/auth-userdb
base_dir = /var/run/dovecot/
disable_plaintext_auth = no
first_valid_gid = 105
first_valid_uid = 105
hostname = ...
imap_client_workarounds = delay-newmail tb-extra-mailbox-sep tb-lsub-flags
imap_idle_notify_interval = 10 mins
last_valid_uid = 105
listen = ...
lmtp_save_to_detail_mailbox = yes
login_log_format_elements = user=<%u> method=%m rip=%r lip=%l mpid=%e %c
mail_gid = vimap
mail_home = /var/imap/spool/%1n/%n
mail_location = mdbox:~/mdbox
mail_plugins = " fts fts_lucene acl"
mail_temp_dir = /var/imap/tmp
mail_uid = vimap
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope encoded-character 
vacation subaddress comparator-i;ascii-numeric relational regex imap4flags 
copy include variables body enotify environment mailbox date ihave
mbox_write_locks = fcntl
mdbox_rotate_interval = 1 days
namespace {
  list = children
  location = 
mdbox:/var/imap/spool/%%1n/%%n/mdbox:INDEXPVT=/var/imap/spool/%1n/%n/mdbox/shared/%%u
  prefix = User/%%u/
  separator = /
  subscriptions = no
  type = shared
}
namespace expunged {
  hidden = yes
  list = no
  location = mdbox:/var/imap/spool/%1n/%n/mdbox:MAILBOXDIR=expunged
  prefix = .EXPUNGED/
  separator = /
  subscriptions = no
  type = private
}
namespace inbox {
  inbox = yes
  location = mdbox:/var/imap/spool/%1n/%n/mdbox
  mailbox Drafts {
    auto = subscribe
    special_use = \Drafts
  }
  mailbox Learn {
    auto = subscribe
  }
  mailbox Learn/Ham {
    auto = subscribe
  }
  mailbox Learn/Spam {
    auto = subscribe
  }
  mailbox Sent {
    auto = subscribe
    special_use = \Sent
  }
  mailbox Spam {
    auto = subscribe
    special_use = \Junk
  }
  mailbox Trash {
    auto = subscribe
    special_use = \Trash
  }
  mailbox virtual/All {
    special_use = \All
  }
  mailbox virtual/Flagged {
    special_use = \Flagged
  }
  prefix = 
  separator = /
  type = private
}
passdb {
  args = /etc/dovecot/master-users
  driver = passwd-file
  master = yes
}
passdb {
  args = /etc/dovecot/dovecot-ldap.conf.ext
  driver = ldap
}
passdb {
  args = /etc/dovecot/extra-users
  driver = passwd-file
}
plugin {
  acl = vfile:/var/imap/global-acls:cache_secs=300
  acl_shared_dict = file:/var/imap/shared-mailboxes/shared-mailboxes
  fts = lucene
  fts_autoindex = yes
  fts_lucene = whitespace_chars=@.
  lazy_expunge = .EXPUNGED/
  lazy_expunge_only_last_instance = yes
  recipient_delimiter = +
  sieve = ~/.dovecot.sieve
  sieve_dir = ~/sieve
  sieve_max_actions = 32
  sieve_max_redirects = 4
  sieve_max_script_size = 1M
}
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
postmaster_address = postmaster at ...
protocols = imap pop3 lmtp sieve
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
  unix_listener auth-userdb {
    group = vimap
    mode = 0600
    user = vimap
  }
  user = $default_internal_user
}
service imap-login {
  process_min_avail = 4
  service_count = 0
}
service imap {
  process_limit = 1024
  vsz_limit = 256 M
}
service lmtp {
  inet_listener lmtp {
    address = ...
    port = 24
  }
}
service managesieve-login {
  inet_listener sieve {
    port = 4190
  }
  inet_listener sieve_deprecated {
    port = 2000
  }
  service_count = 1
  vsz_limit = 64 M
}
service pop3-login {
  inet_listener pop3s {
    port = 995
    ssl = yes
  }
  process_min_avail = 4
  service_count = 0
}
service pop3 {
  process_limit = 512
}
ssl_cert = </etc/dovecot/ssl/...
ssl_key = </etc/dovecot/ssl/...
userdb {
  args = /etc/dovecot/dovecot-ldap.conf.ext
  driver = ldap
}
userdb {
  args = uid=vimap gid=vimap home=/var/imap/spool/%1n/%n
  driver = static
}
protocol lda {
  mail_plugins = " fts fts_lucene acl sieve"
}
protocol imap {
  mail_max_userip_connections = 20
  mail_plugins = " fts fts_lucene acl imap_acl"
}
protocol lmtp {
  mail_plugins = " fts fts_lucene acl sieve"
}
protocol sieve {
  mail_max_userip_connections = 10
  managesieve_implementation_string = Dovecot Pigeonhole
  managesieve_logout_format = bytes=%i/%o
  managesieve_max_line_length = 65536
}
protocol pop3 {
  mail_max_userip_connections = 20
}