[Dovecot] assertion after upgrading to 1.1rc7 from 1.1rc3

[Nuno Lopes]

Hi,
    I'm getting this assertion after making an upgrade from 1.1rc3 to
1.1rc7. Deleting the index files solves the problem. This seems to
happen only to some accounts but I haven't managed to find which ones.
I'm using dovecot's deliver to deliver the messages.

Panic: IMAP(user at example.com): file index-sort-string.c: line 575
(index_sort_add_ids_range): assertion failed: (strcmp(left_str, str) < 0)

Here goes the output of dovecot -n

# 1.1.rc7: /opt/dovecot-1.1.rc7/etc/dovecot.conf
base_dir: /var/run/dovecot/
protocols: imap
listen: *:10143
ssl_disable: yes
disable_plaintext_auth: no
shutdown_clients: no
login_dir: /var/run/dovecot/login
login_executable: /opt/dovecot/libexec/dovecot/imap-login
login_process_per_connection: no
login_max_connections: 400
max_mail_processes: 750
verbose_proctitle: yes
mail_uid: 501
mail_gid: 100
mmap_disable: yes
mail_nfs_storage: yes
mail_nfs_index: yes
mail_plugins: quota imap_quota zlib
mail_plugin_dir: /opt/dovecot/lib/dovecot/imap
auth default:
  executable: /opt/dovecot/libexec/dovecot/dovecot-auth
  user: nobody
  passdb:
    driver: ldap
    args: /opt/dovecot/etc/dovecot-ldap.conf
  userdb:
    driver: ldap
    args: /opt/dovecot/etc/dovecot-ldap.conf
  socket:
    type: listen
    master:
      path: /var/run/dovecot/auth-master
      mode: 384
      user: vmail
      group: nogroup
plugin:
  quota: maildir
  quota_rule: *:storage=2G
  quota_rule2: Trash:storage=102400
  quota_rule3: INBOX.Trash:storage=102400