[Dovecot] Unable to subscribe to newly created subfolders under public mailboxes with acl plugin enabled

[Max Ivanov]

I've "group" namespace and b2b mailbox under it. I'm unable to
subscribe to it and deliver emails there.

Here is my problem: if I create subfolder (lets name it "subf") under
b2b mailbox I'm unable to subscribe to it until acl plugin is enabled.
Even if I put dovecot-acl file in .b2b.subf folder with anyone full
rights dovecot-acl-list doesn't get populated with new subfoler. If I
put it there manually I'm able to see subf folder in subscribe dialog
in TB, but dovecot-acl-list is regulary updated, isn't it? Updated
file is missing subf entry again.

If I disable acl plugin everything works fine, but I'd like to keep it
enabled. Is it a bug or misconfiguration?

My dovecot version is 1.2 rc3

here is dovecot -n authput

protocols: imap managesieve
ssl: yes
ssl_ca_file: /usr/share/ca-certificates/floristCA-cacert.pem
ssl_cert_file: /var/lib/ssl/certs/imap.florist.my-cert.pem
ssl_key_file: /var/lib/ssl/private/imap.florist.my-key.pem
ssl_cipher_list: ALL:!LOW:!SSLv2
disable_plaintext_auth: yes
verbose_ssl: yes
login_dir: /var/run/dovecot/login
login_executable(default): /usr/libexec/dovecot/imap-login
login_executable(imap): /usr/libexec/dovecot/imap-login
login_executable(managesieve): /usr/libexec/dovecot/managesieve-login
login_processes_count: 5
verbose_proctitle: yes
first_valid_uid: 1000
mail_privileged_group: mail
mail_location: maildir:/var/spool/mail/dovecot/%n:INBOX=/var/spool/mail/dovecot/%n/INBOX
mail_debug: yes
mail_executable(default): /usr/libexec/dovecot/imap
mail_executable(imap): /usr/libexec/dovecot/imap
mail_executable(managesieve): /usr/libexec/dovecot/managesieve
mail_plugins(default): acl fts fts_squat
mail_plugins(imap): acl fts fts_squat
mail_plugins(managesieve):
mail_plugin_dir(default): /usr/lib/dovecot/modules/imap
mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap
mail_plugin_dir(managesieve): /usr/lib/dovecot/modules/managesieve
namespace:
  type: private
  separator: /
  inbox: yes
  list: yes
  subscriptions: yes
namespace:
  type: public
  separator: /
  prefix: group/
  location: maildir:/var/spool/mail/groupmail
  list: yes
  subscriptions: yes
auth default:
  verbose: yes
  passdb:
    driver: pam
    args: session=yes
  userdb:
    driver: passwd
    args: blocking=yes
  socket:
    type: listen
    client:
      path: /var/run/dovecot/auth-client
      mode: 432
    master:
      path: /var/run/dovecot/auth-master
      mode: 438
plugin:
  acl: vfile
  lazy_expunge: .EXPUNGED/ .DELETED/ .DELETED/.EXPUNGED/
  sieve: ~/.dovecot.sieve
  sieve_storage: ~/sieve
  fts: squat
  fts_squat: partial=4 full=4