dovecot - Jan 2017 - Fatal error with IMAP MOVE from a shared mailbox to Trash folder

Hello everyone.
I have a problem using Dovecot 2.2.26 with ACL plugin and deleting e-mails
from a shared mailbox.

My user doesn't have the "expunge" permission on the shared
mailbox, but it
has the "write-deleted" permission. So, when I delete a message from
the
shared mailbox using a client that implements the IMAP MOVE command, it
tries to move the message to my Trash folder. Then the server closes the
connection to the client (process aborted) and I get three lines in the log
file with a backtrace and "Fatal" error. In this case the message
doesn't
get copied or moved from the shared folder and the client complaints. I
found the same thing happens whenever I try to move anything between
folders of the shared mailbox itself, while logged in with my user. I can
move messages inside my own mailbox just fine.

If I try the same operation from a client that uses the IMAP COPY + DELETE
commands, no errors are logged and the outcome is as expected: the message
gets copied from the shared folder to my Trash and gets the flag
"\Deleted"
set on the shared folder.

My setup is as follows:

  Dovecot: 2.2.26.0
  OS: Ubuntu 16.04.1 LTS
  CPU architecture: x86_64
  Filesystem: ext4


The relevant lines from mail.err log:

Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Panic: file
mail-storage.c: line 2143 (mailbox_save_context_reset): assertion failed:
(ctx->copying_via_save)
Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Error: Raw
backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x9438e) [0x7fbcd478538e] ->
/usr/lib/dovecot/libdovecot.so.0(+0x9447c) [0x7fbcd478547c] ->
/usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7fbcd471ea4e] ->
/usr/lib/dovecot/libdovecot-storage.so.0(+0x41b78) [0x7fbcd4a50b78] ->
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_save_cancel+0x73)
[0x7fbcd4a53d73] -> /usr/lib/dovecot/modules/lib01_acl_plugin.so(+0xe142)
[0x7fbcd3f1d142] -> /usr/lib/dovecot/libdovecot-storage.so.0(+0x4516d)
[0x7fbcd4a5416d] ->
/usr/lib/dovecot/libdovecot-storage.so.0(mailbox_move+0x23)
[0x7fbcd4a54333] -> dovecot/imap(+0xf9c5) [0x557cf98629c5] ->
dovecot/imap(command_exec+0xa6) [0x557cf986f196] -> dovecot/imap(+0x1a4c2)
[0x557cf986d4c2] -> dovecot/imap(+0x1a550) [0x557cf986d550] ->
dovecot/imap(client_handle_input+0x195) [0x557cf986d915] ->
dovecot/imap(client_input+0x85) [0x557cf986de25] ->
/usr/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x4c) [0x7fbcd4799bdc] ->
/usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0x10a)
[0x7fbcd479b09a] ->
/usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x25) [0x7fbcd4799c65]
-> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7fbcd4799e08] ->
/usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7fbcd4724f53]
-> dovecot/imap(main+0x322) [0x557cf9860ca2] ->
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) [0x7fbcd4348830] ->
dovecot/imap(+0xde1f) [0x557cf9860e1f]
Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Fatal: master:
service(imap): child 6907 killed with signal 6 (core dumped)


Dovecot configuration (doveadm -n):

# 2.2.26.0 (23d1de6): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.4.16 (fed8554)
# OS: Linux 4.4.0-57-generic x86_64 Ubuntu 16.04.1 LTS
auth_cache_negative_ttl = 10 mins
auth_cache_size = 2 M
auth_master_user_separator = *
auth_mechanisms = plain login
first_valid_uid = 12
last_valid_uid = 12
mail_location = maildir:~/Maildir
mail_plugins = acl quota notify mail_log stats lazy_expunge
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope encoded-character
vacation subaddress comparator-i;ascii-numeric relational regex imap4flags
copy include variables body enotify environment mailbox date index ihave
duplicate mime foreverypart extracttext
namespace casellecondivise {
  list = children
  location = maildir:%%h/Maildir:INDEXPVT=~/Maildir/shared/%%u
  prefix = Caselle condivise/%%u/
  separator = /
  subscriptions = no
  type = shared
}
namespace expunged {
  hidden = yes
  list = no
  location = maildir:/var/expunged/%n/Expunged
  prefix = EXPUNGED/
  separator = /
}
namespace inbox {
  inbox = yes
  location   mailbox Archive {
    auto = subscribe
    special_use = \Archive
  }
  mailbox Drafts {
    auto = subscribe
    special_use = \Drafts
  }
  mailbox Junk {
    auto = subscribe
    special_use = \Junk
  }
  mailbox Sent {
    auto = subscribe
    special_use = \Sent
  }
  mailbox Trash {
    auto = subscribe
    special_use = \Trash
  }
  prefix   separator = /
  type = private
}
passdb {
  args = /etc/dovecot/dovecot-ldap.conf.ext
  driver = ldap
}
plugin {
  acl = vfile:/etc/dovecot/global-acls:cache_secs=300
  acl_shared_dict = file:/etc/dovecot/shared/shared-mailboxes
  lazy_expunge = EXPUNGED/
  lazy_expunge_only_last_instance = yes
  mail_log_events = delete copy flag_change save undelete expunge
  mail_log_fields = uid box msgid size
  quota = maildir:user quota
  quota_exceeded_message = (Quota exceeded) La casella di posta elettronica
del destinatario ? piena.
  quota_rule = *:storage=1G
  quota_rule2 = Trash:storage=+100M
  quota_warning = storage=95%% quota-warning 95 %u
  quota_warning2 = storage=100%% quota-warning 100 %u
  sieve = file:~/sieve;active=~/.dovecot.sieve
  stats_command_min_time = 1 mins
  stats_domain_min_time = 12 hours
  stats_ip_min_time = 12 hours
  stats_memory_limit = 32 M
  stats_refresh = 30 secs
  stats_session_min_time = 15 mins
  stats_track_cmds = yes
  stats_user_min_time = 1 hours
}
protocols = " imap sieve"
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = mail
    mode = 0666
    user = postfix
  }
  unix_listener auth-userdb {
    group = mail
    user = mail
  }
}
service dict {
  unix_listener dict {
    group = mail
    mode = 0600
    user = mail
  }
}
service imap-login {
  process_limit = 300
  process_min_avail = 2
}
service managesieve-login {
  inet_listener sieve {
    port = 4190
  }
}
service quota-warning {
  executable = script /etc/dovecot/scripts/quota-warning.sh
  unix_listener quota-warning {
    group = mail
    user = mail
  }
}
service stats {
  fifo_listener stats-mail {
    mode = 0600
    user = mail
  }
}
ssl = required
ssl_cert = </etc/ssl/certs/pac.apg23.org.pem
ssl_key =  # hidden, use -P to show it
userdb {
  args = /etc/dovecot/dovecot-sql.conf.ext
  default_fields = uid=mail gid=mail home=/var/mail/%u master_user=%u
  driver = sql
}
userdb {
  args = /etc/dovecot/dovecot-ldap.conf.ext
  default_fields = uid=mail gid=mail home=/var/mail/%u master_user=%u
  driver = ldap
}
protocol lda {
  mail_plugins = acl quota notify mail_log stats lazy_expunge sieve
}
protocol imap {
  mail_max_userip_connections = 25
  mail_plugins = acl quota notify mail_log stats lazy_expunge imap_quota
imap_stats
}

I tested this with different users with the same result.
I tested and reproduced the error with Thunderbird and Roundcube.
The Apple Mail client uses IMAP COPY + DELETE, instead of IMAP MOVE, and no
errors are reported. So I think it's related to the IMAP MOVE
implementation on Dovecot server.


Has anyone seen the same error?
Any suggestions? Is this a Dovecot bug?

---
Daniele Barresi

On Tue, Dec 27, 2016, at 11:35 AM, Daniele Barresi
wrote:
> Hello everyone.
> I have a problem using Dovecot 2.2.26 with ACL plugin and deleting e-mails
> from a shared mailbox.
> 
> My user doesn't have the "expunge" permission on the shared
mailbox, but it
> has the "write-deleted" permission. So, when I delete a message
from the
> shared mailbox using a client that implements the IMAP MOVE command, it
> tries to move the message to my Trash folder. Then the server closes the
> connection to the client (process aborted) and I get three lines in the log
> file with a backtrace and "Fatal" error. In this case the message
doesn't
> get copied or moved from the shared folder and the client complaints. I
> found the same thing happens whenever I try to move anything between
> folders of the shared mailbox itself, while logged in with my user. I can
> move messages inside my own mailbox just fine.
I don't know about the specific errors emitted, but I've encountered the
same behavior.  As it turns out, the required behavior per RFC 6851 Section 4.2
is that the message cannot be MOVE'd without the expunge permission:

4.2.  RFC 4314, Access Control List (ACL)

   The ACL rights [RFC4314] required for MOVE and UID MOVE are the union
   of the ACL rights required for UID STORE, UID COPY, and UID EXPUNGE.

You should be able to get the old behavior back by overriding the CAPABILITY
response in the dovecot configuration to exclude "MOVE".

Hope that helps.

V/r,
James Cassell

On 12/27/2016 06:35 PM, Daniele Barresi wrote:
> Hello everyone.
> I have a problem using Dovecot 2.2.26 with ACL plugin and deleting e-mails
> from a shared mailbox.
>
> My user doesn't have the "expunge" permission on the shared
mailbox, but it
> has the "write-deleted" permission. So, when I delete a message
from the
> shared mailbox using a client that implements the IMAP MOVE command, it
> tries to move the message to my Trash folder. Then the server closes the
> connection to the client (process aborted) and I get three lines in the log
> file with a backtrace and "Fatal" error. In this case the message
doesn't
> get copied or moved from the shared folder and the client complaints. I
> found the same thing happens whenever I try to move anything between
> folders of the shared mailbox itself, while logged in with my user. I can
> move messages inside my own mailbox just fine.
>
> If I try the same operation from a client that uses the IMAP COPY + DELETE
> commands, no errors are logged and the outcome is as expected: the message
> gets copied from the shared folder to my Trash and gets the flag
"\Deleted"
> set on the shared folder.
>
> My setup is as follows:
>
>    Dovecot: 2.2.26.0
>    OS: Ubuntu 16.04.1 LTS
>    CPU architecture: x86_64
>    Filesystem: ext4
>
>
> The relevant lines from mail.err log:
>
> Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Panic: file
> mail-storage.c: line 2143 (mailbox_save_context_reset): assertion failed:
> (ctx->copying_via_save)
> Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Error: Raw
> backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x9438e) [0x7fbcd478538e]
->
> /usr/lib/dovecot/libdovecot.so.0(+0x9447c) [0x7fbcd478547c] ->
> /usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7fbcd471ea4e] ->
> /usr/lib/dovecot/libdovecot-storage.so.0(+0x41b78) [0x7fbcd4a50b78] ->
> /usr/lib/dovecot/libdovecot-storage.so.0(mailbox_save_cancel+0x73)
> [0x7fbcd4a53d73] ->
/usr/lib/dovecot/modules/lib01_acl_plugin.so(+0xe142)
> [0x7fbcd3f1d142] -> /usr/lib/dovecot/libdovecot-storage.so.0(+0x4516d)
> [0x7fbcd4a5416d] ->
> /usr/lib/dovecot/libdovecot-storage.so.0(mailbox_move+0x23)
> [0x7fbcd4a54333] -> dovecot/imap(+0xf9c5) [0x557cf98629c5] ->
> dovecot/imap(command_exec+0xa6) [0x557cf986f196] ->
dovecot/imap(+0x1a4c2)
> [0x557cf986d4c2] -> dovecot/imap(+0x1a550) [0x557cf986d550] ->
> dovecot/imap(client_handle_input+0x195) [0x557cf986d915] ->
> dovecot/imap(client_input+0x85) [0x557cf986de25] ->
> /usr/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x4c) [0x7fbcd4799bdc]
->
> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0x10a)
> [0x7fbcd479b09a] ->
> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x25) [0x7fbcd4799c65]
> -> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7fbcd4799e08]
->
> /usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7fbcd4724f53]
> -> dovecot/imap(main+0x322) [0x557cf9860ca2] ->
> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) [0x7fbcd4348830]
->
> dovecot/imap(+0xde1f) [0x557cf9860e1f]
> Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Fatal: master:
> service(imap): child 6907 killed with signal 6 (core dumped)
>
>
> Dovecot configuration (doveadm -n):
>
> # 2.2.26.0 (23d1de6): /etc/dovecot/dovecot.conf
> # Pigeonhole version 0.4.16 (fed8554)
> # OS: Linux 4.4.0-57-generic x86_64 Ubuntu 16.04.1 LTS
> auth_cache_negative_ttl = 10 mins
> auth_cache_size = 2 M
> auth_master_user_separator = *
> auth_mechanisms = plain login
> first_valid_uid = 12
> last_valid_uid = 12
> mail_location = maildir:~/Maildir
> mail_plugins = acl quota notify mail_log stats lazy_expunge
> managesieve_notify_capability = mailto
> managesieve_sieve_capability = fileinto reject envelope encoded-character
> vacation subaddress comparator-i;ascii-numeric relational regex imap4flags
> copy include variables body enotify environment mailbox date index ihave
> duplicate mime foreverypart extracttext
> namespace casellecondivise {
>    list = children
>    location = maildir:%%h/Maildir:INDEXPVT=~/Maildir/shared/%%u
>    prefix = Caselle condivise/%%u/
>    separator = /
>    subscriptions = no
>    type = shared
> }
> namespace expunged {
>    hidden = yes
>    list = no
>    location = maildir:/var/expunged/%n/Expunged
>    prefix = EXPUNGED/
>    separator = /
> }
> namespace inbox {
>    inbox = yes
>    location >    mailbox Archive {
>      auto = subscribe
>      special_use = \Archive
>    }
>    mailbox Drafts {
>      auto = subscribe
>      special_use = \Drafts
>    }
>    mailbox Junk {
>      auto = subscribe
>      special_use = \Junk
>    }
>    mailbox Sent {
>      auto = subscribe
>      special_use = \Sent
>    }
>    mailbox Trash {
>      auto = subscribe
>      special_use = \Trash
>    }
>    prefix >    separator = /
>    type = private
> }
> passdb {
>    args = /etc/dovecot/dovecot-ldap.conf.ext
>    driver = ldap
> }
> plugin {
>    acl = vfile:/etc/dovecot/global-acls:cache_secs=300
>    acl_shared_dict = file:/etc/dovecot/shared/shared-mailboxes
>    lazy_expunge = EXPUNGED/
>    lazy_expunge_only_last_instance = yes
>    mail_log_events = delete copy flag_change save undelete expunge
>    mail_log_fields = uid box msgid size
>    quota = maildir:user quota
>    quota_exceeded_message = (Quota exceeded) La casella di posta
elettronica
> del destinatario ? piena.
>    quota_rule = *:storage=1G
>    quota_rule2 = Trash:storage=+100M
>    quota_warning = storage=95%% quota-warning 95 %u
>    quota_warning2 = storage=100%% quota-warning 100 %u
>    sieve = file:~/sieve;active=~/.dovecot.sieve
>    stats_command_min_time = 1 mins
>    stats_domain_min_time = 12 hours
>    stats_ip_min_time = 12 hours
>    stats_memory_limit = 32 M
>    stats_refresh = 30 secs
>    stats_session_min_time = 15 mins
>    stats_track_cmds = yes
>    stats_user_min_time = 1 hours
> }
> protocols = " imap sieve"
> service auth {
>    unix_listener /var/spool/postfix/private/auth {
>      group = mail
>      mode = 0666
>      user = postfix
>    }
>    unix_listener auth-userdb {
>      group = mail
>      user = mail
>    }
> }
> service dict {
>    unix_listener dict {
>      group = mail
>      mode = 0600
>      user = mail
>    }
> }
> service imap-login {
>    process_limit = 300
>    process_min_avail = 2
> }
> service managesieve-login {
>    inet_listener sieve {
>      port = 4190
>    }
> }
> service quota-warning {
>    executable = script /etc/dovecot/scripts/quota-warning.sh
>    unix_listener quota-warning {
>      group = mail
>      user = mail
>    }
> }
> service stats {
>    fifo_listener stats-mail {
>      mode = 0600
>      user = mail
>    }
> }
> ssl = required
> ssl_cert = </etc/ssl/certs/pac.apg23.org.pem
> ssl_key =  # hidden, use -P to show it
> userdb {
>    args = /etc/dovecot/dovecot-sql.conf.ext
>    default_fields = uid=mail gid=mail home=/var/mail/%u master_user=%u
>    driver = sql
> }
> userdb {
>    args = /etc/dovecot/dovecot-ldap.conf.ext
>    default_fields = uid=mail gid=mail home=/var/mail/%u master_user=%u
>    driver = ldap
> }
> protocol lda {
>    mail_plugins = acl quota notify mail_log stats lazy_expunge sieve
> }
> protocol imap {
>    mail_max_userip_connections = 25
>    mail_plugins = acl quota notify mail_log stats lazy_expunge imap_quota
> imap_stats
> }
>
> I tested this with different users with the same result.
> I tested and reproduced the error with Thunderbird and Roundcube.
> The Apple Mail client uses IMAP COPY + DELETE, instead of IMAP MOVE, and no
> errors are reported. So I think it's related to the IMAP MOVE
> implementation on Dovecot server.
>
>
> Has anyone seen the same error?
> Any suggestions? Is this a Dovecot bug?
>
> ---
> Daniele Barresi
Hi!

We'll open a bug on this. Thanks for reporting it.

Aki

On Tue, Jan 3, 2017, at 06:14 PM, Aki Tuomi wrote:
> 
> 
> On 12/27/2016 06:35 PM, Daniele Barresi wrote:
> > Hello everyone.
> > I have a problem using Dovecot 2.2.26 with ACL plugin and deleting
e-mails
> > from a shared mailbox.
> >
> > My user doesn't have the "expunge" permission on the
shared mailbox, but it
> > has the "write-deleted" permission. So, when I delete a
message from the
> > shared mailbox using a client that implements the IMAP MOVE command,
it
> > tries to move the message to my Trash folder. Then the server closes
the
> > connection to the client (process aborted) and I get three lines in
the log
> > file with a backtrace and "Fatal" error. In this case the
message doesn't
> > get copied or moved from the shared folder and the client complaints.
I
> > found the same thing happens whenever I try to move anything between
> > folders of the shared mailbox itself, while logged in with my user. I
can
> > move messages inside my own mailbox just fine.
> >
> > If I try the same operation from a client that uses the IMAP COPY +
DELETE
> > commands, no errors are logged and the outcome is as expected: the
message
> > gets copied from the shared folder to my Trash and gets the flag
"\Deleted"
> > set on the shared folder.
> >
> > My setup is as follows:
> >
> >    Dovecot: 2.2.26.0
> >    OS: Ubuntu 16.04.1 LTS
> >    CPU architecture: x86_64
> >    Filesystem: ext4
> >
> >
> > The relevant lines from mail.err log:
> >
> > Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Panic: file
> > mail-storage.c: line 2143 (mailbox_save_context_reset): assertion
failed:
> > (ctx->copying_via_save)
> > Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Error: Raw
> > backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x9438e) [0x7fbcd478538e]
->
> > /usr/lib/dovecot/libdovecot.so.0(+0x9447c) [0x7fbcd478547c] ->
> > /usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7fbcd471ea4e] ->
> > /usr/lib/dovecot/libdovecot-storage.so.0(+0x41b78) [0x7fbcd4a50b78]
->
> > /usr/lib/dovecot/libdovecot-storage.so.0(mailbox_save_cancel+0x73)
> > [0x7fbcd4a53d73] ->
/usr/lib/dovecot/modules/lib01_acl_plugin.so(+0xe142)
> > [0x7fbcd3f1d142] ->
/usr/lib/dovecot/libdovecot-storage.so.0(+0x4516d)
> > [0x7fbcd4a5416d] ->
> > /usr/lib/dovecot/libdovecot-storage.so.0(mailbox_move+0x23)
> > [0x7fbcd4a54333] -> dovecot/imap(+0xf9c5) [0x557cf98629c5] ->
> > dovecot/imap(command_exec+0xa6) [0x557cf986f196] ->
dovecot/imap(+0x1a4c2)
> > [0x557cf986d4c2] -> dovecot/imap(+0x1a550) [0x557cf986d550] ->
> > dovecot/imap(client_handle_input+0x195) [0x557cf986d915] ->
> > dovecot/imap(client_input+0x85) [0x557cf986de25] ->
> > /usr/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x4c)
[0x7fbcd4799bdc] ->
> > /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0x10a)
> > [0x7fbcd479b09a] ->
> > /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x25)
[0x7fbcd4799c65]
> > -> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x38)
[0x7fbcd4799e08] ->
> > /usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13)
[0x7fbcd4724f53]
> > -> dovecot/imap(main+0x322) [0x557cf9860ca2] ->
> > /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)
[0x7fbcd4348830] ->
> > dovecot/imap(+0xde1f) [0x557cf9860e1f]
> > Dec 27 15:21:18 dovecot dovecot: imap(danielebarresi): Fatal: master:
> > service(imap): child 6907 killed with signal 6 (core dumped)
> >
> >
> > Dovecot configuration (doveadm -n):
> >
> > # 2.2.26.0 (23d1de6): /etc/dovecot/dovecot.conf
> > # Pigeonhole version 0.4.16 (fed8554)
> > # OS: Linux 4.4.0-57-generic x86_64 Ubuntu 16.04.1 LTS
> > auth_cache_negative_ttl = 10 mins
> > auth_cache_size = 2 M
> > auth_master_user_separator = *
> > auth_mechanisms = plain login
> > first_valid_uid = 12
> > last_valid_uid = 12
> > mail_location = maildir:~/Maildir
> > mail_plugins = acl quota notify mail_log stats lazy_expunge
> > managesieve_notify_capability = mailto
> > managesieve_sieve_capability = fileinto reject envelope
encoded-character
> > vacation subaddress comparator-i;ascii-numeric relational regex
imap4flags
> > copy include variables body enotify environment mailbox date index
ihave
> > duplicate mime foreverypart extracttext
> > namespace casellecondivise {
> >    list = children
> >    location = maildir:%%h/Maildir:INDEXPVT=~/Maildir/shared/%%u
> >    prefix = Caselle condivise/%%u/
> >    separator = /
> >    subscriptions = no
> >    type = shared
> > }
> > namespace expunged {
> >    hidden = yes
> >    list = no
> >    location = maildir:/var/expunged/%n/Expunged
> >    prefix = EXPUNGED/
> >    separator = /
> > }
> > namespace inbox {
> >    inbox = yes
> >    location > >    mailbox Archive {
> >      auto = subscribe
> >      special_use = \Archive
> >    }
> >    mailbox Drafts {
> >      auto = subscribe
> >      special_use = \Drafts
> >    }
> >    mailbox Junk {
> >      auto = subscribe
> >      special_use = \Junk
> >    }
> >    mailbox Sent {
> >      auto = subscribe
> >      special_use = \Sent
> >    }
> >    mailbox Trash {
> >      auto = subscribe
> >      special_use = \Trash
> >    }
> >    prefix > >    separator = /
> >    type = private
> > }
> > passdb {
> >    args = /etc/dovecot/dovecot-ldap.conf.ext
> >    driver = ldap
> > }
> > plugin {
> >    acl = vfile:/etc/dovecot/global-acls:cache_secs=300
> >    acl_shared_dict = file:/etc/dovecot/shared/shared-mailboxes
> >    lazy_expunge = EXPUNGED/
> >    lazy_expunge_only_last_instance = yes
> >    mail_log_events = delete copy flag_change save undelete expunge
> >    mail_log_fields = uid box msgid size
> >    quota = maildir:user quota
> >    quota_exceeded_message = (Quota exceeded) La casella di posta
elettronica
> > del destinatario ? piena.
> >    quota_rule = *:storage=1G
> >    quota_rule2 = Trash:storage=+100M
> >    quota_warning = storage=95%% quota-warning 95 %u
> >    quota_warning2 = storage=100%% quota-warning 100 %u
> >    sieve = file:~/sieve;active=~/.dovecot.sieve
> >    stats_command_min_time = 1 mins
> >    stats_domain_min_time = 12 hours
> >    stats_ip_min_time = 12 hours
> >    stats_memory_limit = 32 M
> >    stats_refresh = 30 secs
> >    stats_session_min_time = 15 mins
> >    stats_track_cmds = yes
> >    stats_user_min_time = 1 hours
> > }
> > protocols = " imap sieve"
> > service auth {
> >    unix_listener /var/spool/postfix/private/auth {
> >      group = mail
> >      mode = 0666
> >      user = postfix
> >    }
> >    unix_listener auth-userdb {
> >      group = mail
> >      user = mail
> >    }
> > }
> > service dict {
> >    unix_listener dict {
> >      group = mail
> >      mode = 0600
> >      user = mail
> >    }
> > }
> > service imap-login {
> >    process_limit = 300
> >    process_min_avail = 2
> > }
> > service managesieve-login {
> >    inet_listener sieve {
> >      port = 4190
> >    }
> > }
> > service quota-warning {
> >    executable = script /etc/dovecot/scripts/quota-warning.sh
> >    unix_listener quota-warning {
> >      group = mail
> >      user = mail
> >    }
> > }
> > service stats {
> >    fifo_listener stats-mail {
> >      mode = 0600
> >      user = mail
> >    }
> > }
> > ssl = required
> > ssl_cert = </etc/ssl/certs/pac.apg23.org.pem
> > ssl_key =  # hidden, use -P to show it
> > userdb {
> >    args = /etc/dovecot/dovecot-sql.conf.ext
> >    default_fields = uid=mail gid=mail home=/var/mail/%u master_user=%u
> >    driver = sql
> > }
> > userdb {
> >    args = /etc/dovecot/dovecot-ldap.conf.ext
> >    default_fields = uid=mail gid=mail home=/var/mail/%u master_user=%u
> >    driver = ldap
> > }
> > protocol lda {
> >    mail_plugins = acl quota notify mail_log stats lazy_expunge sieve
> > }
> > protocol imap {
> >    mail_max_userip_connections = 25
> >    mail_plugins = acl quota notify mail_log stats lazy_expunge
imap_quota
> > imap_stats
> > }
> >
> > I tested this with different users with the same result.
> > I tested and reproduced the error with Thunderbird and Roundcube.
> > The Apple Mail client uses IMAP COPY + DELETE, instead of IMAP MOVE,
and no
> > errors are reported. So I think it's related to the IMAP MOVE
> > implementation on Dovecot server.
> >
> >
> > Has anyone seen the same error?
> > Any suggestions? Is this a Dovecot bug?
> >
> > ---
> > Daniele Barresi
> Hi!
> 
> We'll open a bug on this. Thanks for reporting it.
> 
> Aki
Hello,

I'm also seeing this error on Dovecot 2.2.27 from Debian jessie-backports. 
The error seems to come up when trying to move FROM a folder for which the user
doesn't have the EXPUNGE ACL.  It doesn't have to be a shared folder
(and in my case, it is not a shared folder.)  My workaround is to not advertise
the MOVE capability, but long-term, it's better to fix the crash.


V/r,
James Cassell