zlib plugin producing errors on 2.3.0

[Adam Weinberger]

Hello,

I use the zlib and imap_zlib plugins on FreeBSD. As of 2.3.0, my logs
are producing these errors every so often, but AFAICT the messages
themselves aren't getting corrupted.

Panic: file ostream-zlib.c: line 36 (o_stream_zlib_close): assertion failed: (zstream->ostream.finished || zstream->ostream.ostream.stream_errno != 0)
Fatal: master: service(imap): child 80128 killed with signal 6 (core not dumped - set service imap { drop_priv_before_exec=yes })
Panic: file ostream-zlib.c: line 36 (o_stream_zlib_close): assertion failed: (zstream->ostream.finished || zstream->ostream.ostream.stream_errno != 0)
Fatal: master: service(imap): child 80266 killed with signal 6 (core not dumped - set service imap { drop_priv_before_exec=yes })

They always come in pairs like that. Following is my doveconf. Let
me know what else I can provide here. Thanks!

# Adam


# 2.3.0 (c8b89eb): /usr/local/etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.0 (d68c23a1)
# OS: FreeBSD 11.1-RELEASE-p6 amd64  nullfs
auth_mechanisms = plain login
first_valid_gid = 1021
first_valid_uid = 1021
last_valid_gid = 1022
last_valid_uid = 1022
listen = imap.jail.apnoea.adamw.org
mail_location = mdbox:/mail/%u/mail
mail_plugins = " zlib virtual fts fts_lucene"
mail_prefetch_count = 5
namespace inbox {
  inbox = yes
  location = 
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox FreeBSD {
    autoexpunge = 17 weeks
  }
  mailbox FreeBSD/TodaysCommits {
    autoexpunge = 2 days
  }
  mailbox FreeBSD/automation {
    autoexpunge = 1 days
  }
  mailbox FreeBSD/portmgr {
    autoexpunge = 26 weeks
  }
  mailbox FreeBSD/ports {
    autoexpunge = 12 weeks
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    autoexpunge = 30 days
    special_use = \Trash
  }
  mailbox spam/probably {
    autoexpunge = 30 days
  }
  mailbox spam/totally {
    autoexpunge = 5 days
  }
  prefix = 
  separator = /
}
passdb {
  args = scheme=BLF-CRYPT username_format=%u /path/to/userdb.passwd
  driver = passwd-file
}
plugin {
  fts = lucene
  fts_autoindex = yes
  fts_autoindex_max_recent_msgs = 25
  fts_lucene = whitespace_chars=@
  sieve = file:/scripts/sieve/%u.sieve;bindir=/mail/%u/sieve/
  sieve_extensions = +vnd.dovecot.pipe +vnd.dovecot.filter +editheader
  sieve_filter_bin_dir = /scripts/sieve/filter
  sieve_pipe_bin_dir = /scripts/sieve/pipe
  sieve_plugins = sieve_extprograms
}
postmaster_address = postmaster at ...
protocols = imap lmtp
service imap-login {
  inet_listener imaps {
    port = 0
  }
}
service lmtp {
  inet_listener lmtp {
    port = 24
  }
}
ssl = required
ssl_cert = </path/to/fullchain.pem
ssl_cipher_list = TLSv1.2+AEAD:!aNULL
ssl_dh =  # hidden, use -P to show it
ssl_key =  # hidden, use -P to show it
ssl_min_protocol = TLSv1.2
ssl_prefer_server_ciphers = yes
userdb {
  args = username_format=%u /path/to/userdb.passwd
  driver = passwd-file
}
protocol lmtp {
  mail_plugins = " zlib virtual fts fts_lucene sieve"
}
protocol imap {
  mail_max_userip_connections = 20
  mail_plugins = " zlib virtual fts fts_lucene imap_zlib"
}
protocol lda {
  mail_plugins = " zlib virtual fts fts_lucene sieve"
}


--
Adam Weinberger
adamw at adamw.org
http://www.adamw.org