dovecot - Jul 2014 - Dovecot 2.2.13+ Assertion failed in sync_expunge_range

Hi!

I got this error when build dovecot from source (rev 17627), configure it as
imapc proxy (http://wiki2.dovecot.org/HowTo/ImapcProxy) and run imaptest with
clients=2 or more, on latest stable version (2.2.13) and with clients=1 this
error does not occurred.

Jul 16 17:22:26 imap(user771): Panic: file mail-index-sync-update.c: line 250
(sync_expunge_range): assertion failed: (count > 0)
Jul 16 17:22:26 imap(user771): Error: Raw backtrace:
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(+0x872a6) [0x7f8a956682a6]
-> /home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(+0x88683)
[0x7f8a95669683] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7f8a956685f9]
-> /home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0x106f13)
[0x7f8a959f5f13] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0x107e5a)
[0x7f8a959f6e5a] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(mail_index_sync_record+0x33)
[0x7f8a959f76a3] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(mail_index_sync_map+0x4e8)
[0x7f8a959f7d97] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(mail_index_map+0x126)
[0x7f8a959e1817] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0xeb410)
[0x7f8a959da410] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0xeb707)
[0x7f8a959da707] -> /home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.
so.0(mail_index_open+0x17e) [0x7f8a959daa33] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(index_storage_mailbox_open+0xe7)
[0x7f8a959c6742] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0x81fd4)
[0x7f8a95970fd4] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0x9a5d4)
[0x7f8a959895d4] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(mailbox_open+0x1d)
[0x7f8a9598975d] -> dovecot/imap() [0x414a3f] ->
dovecot/imap(cmd_select_full+0x204) [0x414fac] ->
dovecot/imap(cmd_select+0x1d) [0x414ff1] -> dovecot/imap(command_exec+0x5f)
[0x41bdf4] -> dovecot/imap() [0x41ad47] -> dovecot/imap() [0x41b049] ->
dovecot/imap() [0x41b169] -> dovecot/imap(client_handle_input+0x7e)
[0x41b1e9] -> dovecot/imap(client_input+0xe6) [0x41b37c] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(io_loop_call_io+0xb6)
[0x7f8a95681c32] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0x1e5)
[0x7f8a95683ce4] -> /home/lion/dovecot-2.2/lib/
dovecot/libdovecot.so.0(io_loop_handler_run+0x18) [0x7f8a95681dcd] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(io_loop_run+0xaf)
[0x7f8a95681d26]
Jul 16 17:22:26 imap(user771): Panic: file mail-index-sync-update.c: line 250
(sync_expunge_range): assertion failed: (count > 0)
Jul 16 17:22:26 imap(user771): Error: Raw backtrace:
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(+0x872a6) [0x7fc4005942a6]
-> /home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(+0x88683)
[0x7fc400595683] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7fc4005945f9]
-> /home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0x106f13)
[0x7fc400921f13] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0x107e5a)
[0x7fc400922e5a] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(mail_index_sync_record+0x33)
[0x7fc4009236a3] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(mail_index_sync_map+0x4e8)
[0x7fc400923d97] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(mail_index_map+0x126)
[0x7fc40090d817] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0xeb410)
[0x7fc400906410] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0xeb707)
[0x7fc400906707] -> /home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.
so.0(mail_index_open+0x17e) [0x7fc400906a33] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(index_storage_mailbox_open+0xe7)
[0x7fc4008f2742] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0x81fd4)
[0x7fc40089cfd4] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(+0x9a5d4)
[0x7fc4008b55d4] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot-storage.so.0(mailbox_open+0x1d)
[0x7fc4008b575d] -> dovecot/imap() [0x414a3f] ->
dovecot/imap(cmd_select_full+0x204) [0x414fac] ->
dovecot/imap(cmd_select+0x1d) [0x414ff1] -> dovecot/imap(command_exec+0x5f)
[0x41bdf4] -> dovecot/imap() [0x41ad47] -> dovecot/imap() [0x41b049] ->
dovecot/imap() [0x41b169] -> dovecot/imap(client_handle_input+0x7e)
[0x41b1e9] -> dovecot/imap(client_input+0xe6) [0x41b37c] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(io_loop_call_io+0xb6)
[0x7fc4005adc32] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0x1e5)
[0x7fc4005afce4] -> /home/lion/dovecot-2.2/lib/
dovecot/libdovecot.so.0(io_loop_handler_run+0x18) [0x7fc4005addcd] ->
/home/lion/dovecot-2.2/lib/dovecot/libdovecot.so.0(io_loop_run+0xaf)
[0x7fc4005add26]


# 2.2.13 (fd0616d553b0): /home/lion/dovecot-2.2/etc/dovecot/dovecot.conf
# OS: Linux 3.11.0-24-generic x86_64 Ubuntu 12.04.4 LTS
auth_mechanisms = plain login
default_internal_user = lion
default_login_user = lion
disable_plaintext_auth = no
imapc_host = localhost
log_path = /home/lion/dovecot-2.2/var/log/dovecot.log
mail_home = /home/lion/dovecot-2.2/home/vmail/%u
mail_location = imapc:~/imapc
namespace inbox {
  inbox = yes
  location   mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    special_use = \Trash
  }
  prefix }
passdb {
  args = host=localhost port=143
  default_fields = userdb_imapc_user=%u userdb_imapc_password=%w
  driver = imap
}
plugin {
  fts = solr
  fts_solr = url=http://localhost:8080/solr/ break-imap-search
  mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename
  mail_log_fields = uid box msgid size
}
service anvil {
  chroot }
service auth-worker {
  user = $default_internal_user
}
service imap-login {
  chroot   inet_listener imap {
    port = 10143
  }
  inet_listener imaps {
    port = 10993
  }
}
service lmtp {
  chroot }
service pop3-login {
  chroot   inet_listener pop3 {
    port = 10110
  }
  inet_listener pop3s {
    port = 10995
  }
}
ssl = no
userdb {
  driver = prefetch
}