[Dovecot] Seen flag in maildir filename not being respected

[Eduardo M KALINOWSKI]

Hi,

    I'm using dovecot 1.1.2 (but I've noticed this since 1.1.1 which I
was using until yesterday). It seems dovecot is ignoring the "S" flag in
Maildir filenames, and is relying only in its Index Files to determine
if a message has been read or not.

    I say that because if I delete the dovecot.index.* files for a mail
folder, all the mails in there appear as unread. Also, I've tried
accessing the maildir directly (using heirloom-mailx, but mutt should
have done, too) and reading a new message. The file name was changed to
add a "S" to the end, but this message was still marked as "unread" when
the mail folder was accessed via IMAP.

    The flags R, F and T are correctly read from the filename if no
index is present. I haven't tested the other flags.

    I'm using dovecot's deliver, and it creates filenames such as
"1217450416.M77457P5201.mail.kalinowski.com.br,S=1377,W=1411:2,S", that
is, perfectly fine.

dovecot -n:
# 1.1.2: /etc/dovecot/dovecot.conf
log_path: /var/log/dovecot/main.log
info_log_path: /var/log/dovecot/info.log
log_timestamp: %Y-%m-%d %H:%M:%S
ssl_cert_file: /etc/ssl/certs/server.pem
ssl_key_file: /etc/ssl/private/server.pem
login_dir: /var/run/dovecot/login
login_executable: /usr/lib/dovecot/imap-login
login_processes_count: 1
first_valid_uid: 100
mail_privileged_group: mail
mail_location:
maildir:/home/vmail/%d/%n/INBOX:INDEX=/home/vmail/%d/%n/dovecotidx
mail_plugins: quota imap_quota zlib
auth default:
  mechanisms: plain login cram-md5
  passdb:
    driver: passwd-file
    args: username_format=%n /home/vmail/%d/db/passwd
  passdb:
    driver: pam
  userdb:
    driver: static
    args: uid=104 gid=8 home=/home/vmail/%d/%n
  userdb:
    driver: passwd
  socket:
    type: listen
    client:
      path: /var/run/dovecot/auth-client
      mode: 438
    master:
      path: /var/run/dovecot/auth-master
      mode: 384
      user: vmail
      group: mail
plugin:
  quota: maildir
  quota_rule: ?:storage=0
  quota_rule2: Trash:ignore
  quota_rule3: Spam:ignore
  quota_rule4: Spam.Errado:ignore
  sieve: /home/vmail/%d/db/sieves/%n.sieve