Dovecot 2.1.9 shared folder deletion causes fault

[JT]

Hey all,

I'm getting a fault in dovecot (see below) using shared folders. I have
a mailbox that receives new mail (Account X/INBOX). Another account
(Account A) has access to the other account (Account X/INBOX) with ACL
below.

The ACL directory (.DEFAULT) contains:
user=AccountA lrwst

I removed a test email from Account A/INBOX, which is supposed to remove
the email from Account X/INBOX. A fault occurs whenever my client
(Thunderbird) attempts to connect and complete the deletion. Other
actions complete successfully. It only appears to happen when using
Thunderbird. Mac Mail does not cause the fault.

I'm not getting a core dump so all I have is what the log outputs. I can
reproduce this regularly so let me know if you need any additional
information.

Thanks,

JT

===

Version: 2.1.9 (Ubuntu Trustydeb package)
OS: Ubuntu trusty 14.04

2015-06-18T19:17:50.518505+00:00 mail-103 dovecot: imap(XXX): Error: Raw
backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x5e271) [0x7eff3f6d1271]
-> /usr/lib/dovecot/libdovecot.so.0(+0x5e34e) [0x7eff3f6d134e] ->
/usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7eff3f68ca9e] ->
/usr/lib/dovecot/libdovecot-storage.so.0(+0xa7cbc) [0x7eff3f9e2cbc] ->
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_copy+0x6c)
[0x7eff3f9ac8ec] ->
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_move+0x15)
[0x7eff3f9ac985] -> dovecot/imap(+0xded5) [0x7eff3fe78ed5] ->
dovecot/imap(command_exec+0x3c) [0x7eff3fe836dc] ->
dovecot/imap(+0x176cf) [0x7eff3fe826cf] -> dovecot/imap(+0x17785)
[0x7eff3fe82785] -> dovecot/imap(client_handle_input+0x125)
[0x7eff3fe82aa5] -> dovecot/imap(client_input+0x75) [0x7eff3fe82e35] ->
/usr/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x27) [0x7eff3f6e1247]
-> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0xd7)
[0x7eff3f6e1fd7] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x38)
[0x7eff3f6e0de8] ->
/usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13)
[0x7eff3f691c93] -> dovecot/imap(main+0x2c4) [0x7eff3fe772f4] ->
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5) [0x7eff3f2cfec5]
-> dovecot/imap(+0xc460) [0x7eff3fe77460]
2015-06-18T19:17:50.736901+00:00 mail-103 dovecot: imap(XXX): Fatal:
master: service(imap): child 4461 killed with signal 6 (core dumped)
2015-06-18T19:17:51.662157+00:00 mail-103 dovecot: imap(XXX): Panic:
file mail-index.c: line 380 (mail_index_keywords_unref): assertion
failed: (keywords->refcount > 0)
2015-06-18T19:17:51.662969+00:00 mail-103 dovecot: imap(XXX): Error: Raw
backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x5e271) [0x7f3fa05bb271]
-> /usr/lib/dovecot/libdovecot.so.0(+0x5e34e) [0x7f3fa05bb34e] ->
/usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7f3fa0576a9e] ->
/usr/lib/dovecot/libdovecot-storage.so.0(+0xa7cbc) [0x7f3fa08cccbc] ->
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_copy+0x6c)
[0x7f3fa08968ec] ->
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_move+0x15)
[0x7f3fa0896985] -> dovecot/imap(+0xded5) [0x7f3fa0d62ed5] ->
dovecot/imap(command_exec+0x3c) [0x7f3fa0d6d6dc] ->
dovecot/imap(+0x176cf) [0x7f3fa0d6c6cf] -> dovecot/imap(+0x17785)
[0x7f3fa0d6c785] -> dovecot/imap(client_handle_input+0x125)
[0x7f3fa0d6caa5] -> dovecot/imap(client_input+0x75) [0x7f3fa0d6ce35] ->
/usr/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x27) [0x7f3fa05cb247]
-> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0xd7)
[0x7f3fa05cbfd7] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x38)
[0x7f3fa05cade8] ->
/usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13)
[0x7f3fa057bc93] -> dovecot/imap(main+0x2c4) [0x7f3fa0d612f4] ->
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5) [0x7f3fa01b9ec5]
-> dovecot/imap(+0xc460) [0x7f3fa0d61460]
2015-06-18T19:17:51.857451+00:00 mail-103 dovecot: imap(XXX): Fatal:
master: service(imap): child 4464 killed with signal 6 (core dumped)

protocol imap {
  imap_client_workarounds = tb-extra-mailbox-sep
  imap_idle_notify_interval = 1 mins
  mail_max_userip_connections = 10
  mail_plugins = acl quota acl imap_acl quota imap_quota
}

plugin {
  acl = vfile:/etc/dovecot/acl
  acl_defaults_from_inbox = yes
  acl_shared_dict = proxy::acl
...
}

namespace {
  hidden = no
  inbox = yes
  list = yes
  location =
  prefix =
  separator = /
  subscriptions = yes
  type = private
}
namespace {
  hidden = no
  list = children
  location =
maildir:/var/mail/public/Maildir:INDEX=/var/mail/%d/%n/Maildir/public
  prefix = public/
  separator = /
  subscriptions = yes
  type = public
}
namespace {
  list = yes
  location =
maildir:%%h/Maildir:CONTROL=~/Maildir/control/%%u:INDEX=~/Maildir/shared/%%u.indx:INDEXPVT=~/Maildir/shared/%%u.pvt
  prefix = shared/%%u/
  separator = /
  subscriptions = no
  type = shared
}