v2.3.18 2022-02-03  Aki Tuomi <aki.tuomi@open-xchange.com>

	* Removed mail_cache_lookup_finished event. This event wasn't especially
	  useful, but it increased CPU usage significantly.
	* fts: Don't index inline base64 encoded content in FTS indexes using
	  the generic tokenizer. This reduces the FTS index sizes by removing
	  input that is very unlikely to be searched for. See
	  https://doc.dovecot.org/configuration_manual/fts/tokenization for
	  details on how base64 is detected. Only applies when using libfts.
	* lmtp: Session IDs are now preserved through proxied connections, so
	  LMTP sessions can be tracked. This slightly changes the LMTP session
	  ID format by appending ":Tn" (transaction), ":Pn" (proxy connection)
	  and ":Rn" (recipient) counters after the session ID prefix.
	+ Events now have "reason_code" field, which can provide a list of
	  reasons why the event is happening. See
	  https://doc.dovecot.org/admin_manual/event_reasons/
	+ New events are added. See https://doc.dovecot.org/admin_manual/list_of_events/
	+ fts: Added fts_header_excludes and fts_header_includes settings to
	  specify which headers to index. See
	  https://doc.dovecot.org/settings/plugin/fts-plugin#plugin-fts-setting-fts-header-excludes
	  for configuration details.
	+ fts: Initialize the textcat language detection library only once per
	  process. This can reduce CPU usage if fts_languages setting has multiple
	  languages listed and service indexer-worker { service_count } isn't 1.
	  Only applies when using libfts.
	+ lib-storage: Reduced CPU usage significantly for some operations that
	  accessed lots of emails (e.g. fetching all flags in a folder, SORT, ...)
	+ lib: DOVECOT_PREREQ() - Add micro version which enables compiling
	  external plugins against different versions of Dovecot.
	+ lmtp: Added new lmtp_verbose_replies setting that makes errors sent to
	  the LMTP client much more verbose with details about why exactly
	  backend proxy connections or commands are failing.
	+ submission: Support implicit SASL EXTERNAL with
	  submission_client_workarounds=implicit-auth-external. This allows
	  automatically logging in when SSL client certificate is present.
	- *-login: Statistics were disabled if stats process connection was lost.
	- auth: Authentication master user login fails with SCRAM-* SASL mechanisms.
	- auth: With auth_cache_verify_password_with_worker=yes, passdb extra
	  fields in the auth cache got lost.
	- doveadm: Fixed crash if zlib_save_level setting was specified,
	  but zlib_save was unset. v2.3.15 regression.
	- doveadm: Proxying can panic when flushing print output. v2.3.17
	  regression. Fixes:
	  Panic: file ioloop.c: line 865 (io_loop_destroy): assertion failed:
	  (ioloop == current_ioloop)
	- doveadm: stats add --group-by parameter didn't work.
	- fts: Using email-address fts tokenizer could result in excessive memory
	  usage with garbage email input. This could cause the indexer-worker
	  processes to fail due to reaching the VSZ memory size limit.
	  Only applies when using libfts.
	- imap: A SEARCH command timing out while fts returns indexes may timeout
	  returning "NO [SERVERBUG]", while it should return "NO [INUSE]" instead.
	- imap: LIST-EXTENDED doesn't return STATUS for all folders. Sending
	  LIST .. RETURN (SUBSCRIBED STATUS (...)) did not return STATUS for
	  folders that are not subscribed when they have a child folder that is
	  subscribed as mandated by IMAP RFCs.
	- imapc: Mailbox vsize calculation crashed with
	  Panic: file index-mailbox-size.c: line 344 (index_mailbox_vsize_hdr_add_missing):
	  assertion failed: (mails_left > 0)
	- indexer: If indexer-worker crashes, the request it was processing gets
	  stuck in the indexer process. This stops indexing for the folder until
	  indexer process is restarted. v2.3.14 regression.
	- indexer: Process was slowly leaking memory for each indexing request.
	- lib-event: Unnamed events were wrongly filtered out for event/metric
	  filters like "event=abc OR something_independent_of_event_name".
	- lib-index: 64-bit big endian CPUs handle last_used field in
	  dovecot.index.cache wrong.
	- lib-ssl-iostream: Fix buggy OpenSSL error handling without assert-crashing.
	  If there is no error available, log it as an error instead of crashing.
	  The previous fix for this in v2.3.11 was incomplete. Fixes
	  Panic: file istream-openssl.c: line 51 (i_stream_ssl_read_real):
	  assertion failed: (errno != 0)
	- lmtp: Out-of-memory issues can happen when proxying large messages to
	  LMTP backend servers that accept the message data too slow.
	- master: HAProxy header parsing has read buffer overflow if provided
	  header size is invalid. This happens only if inet_listener
	  { haproxy=yes } is configured and only if the remote IP address is in
	  haproxy_trusted_networks.
	- old_stats: Plugin kept increasing memory usage, which became
	  noticeable with long-running imap sessions.
	- stats: Dynamically adding same metric multiple times causes multiple stats.
	- submission-login: Authentication does not accept OAUTH2 token (or
	  other very long credentials) because it considers the line to be too long.
	- submission-login: Process can crash if HELO is pipelined with an
	  invalid domain.
	- submission-proxy: Don't use SASL-IR if it would make the AUTH command
	  line longer than 512 bytes.
	- submission: Service would crash if relay server authentication failed.
	- virtual: FTS search in a virtual folder could crash if there are
	  duplicate mailbox GUIDs. This mainly happened when user had both INBOX
	  and INBOX/INBOX folders and the namespace prefix was INBOX/. Fixes
	  Panic: file hash.c: line 252 (hash_table_insert_node):
	  assertion failed: (opcode == HASH_TABLE_OP_UPDATE)
	- virtual: If mailbox opening fails, the backend mailbox is leaked and
	  process crashes when client disconnects. Fixes
	  Panic: file mail-user.c: line 232 (mail_user_deinit):
	  assertion failed: ((*user)->refcount == 1)
	- virtual: Searching headers in virtual folders didn't always use
	  full-text search indexes, if fts_enforced=no or body.

v2.3.17.1 2021-12-07  Aki Tuomi <aki.tuomi@open-xchange.com>

	- dsync: Add back accidentically removed parameters.
	- lib-ssl-iostream: Fix assert-crash when OpenSSL returned syscall error
	  without errno.
	- master: Dovecot failed to start if ssl_ca was too large.

v2.3.17 2021-10-28  Aki Tuomi <aki.tuomi@open-xchange.com>

	* Dovecot now logs a warning if time seems to jump forward at least
	  100 milliseconds.
	* dict: Lines logged by the dict process now contain the dict name as
	  the prefix.
	* lib-index: mail_cache_fields, mail_always_cache_fields and
	  mail_never_cache_fields now verifies that the listed header names are
	  valid. Especially the UTF8 "–" character has sometimes been wrongly
	  used instead of the ASCII "-".
	+ *-login: Added login_proxy_rawlog_dir setting to capture
	  rawlogs between proxy and backend.
	+ dict: The server process now keeps the last 10 idle dict backends
	  cached for maximum of 30 seconds. Practically this acts as a
	  connection pool for dict-redis and dict-ldap. Note that this doesn't
	  affect dict-sql, because it already had its own internal cache.
	+ doveadm: New stats add/remove commands added to support changing the
	  metrics configuration on runtime.
	+ lazy_expunge: Added lazy_expunge_exclude settings to disable
	  lazy_expunge for specific folders. \Special-use flags can be used as
	  folder names.
	+ lib-lua: Added a new helper function dovecot.restrict_global_variables()
	  to disable or enable defining new global variables.
	- LAYOUT=index List index rebuild was missing.
	- LAYOUT=index: Duplicate GUIDs were not detected.
	- acl: When using acl_ignore_namespace Dovecot attempted to access or
	  create dovecot-acl-list even when the namespace should have been
	  ignored. For virtual namespaces this could have yielded errors about
	  "Read-only file system" or "Permission denied".
	- auth: Setting the "master" passdb field to empty value would
	  cause proxying to fail with an authentication error.
	  Now an empty "master" field is ignored.
	- doveadm-server: Duplicate error lines were sent for failed commands.
	  This didn't normally cause visible problems, except when using
	  wildcards in usernames or -A parameter to go through multiple users.
	- doveadm-server: Logs written by doveadm-server were often missing log
	  prefixes, especially mail_log_prefix for mail commands. Logs sent to
	  doveadm TCP client were also missing log prefixes.
	- doveadm: v2.3 regression: batch command always crashes.
	- doveadm: v2.3.11 regression: Commands failed if ssl_cert or
	  ssl_key files weren't readable by the user running doveadm, even
	  though doveadm didn't actually use these settings
	- imap-hibernate: Process may crash at deinit:
	  Panic: file ioloop.c: line 928 (io_loop_destroy): assertion failed:
	  (ioloop->cur_ctx == NULL).
	- imap: Using imap_fetch_failure=no-after can cause assert-crash
	  with some IMAP commands if reading the mail fails (e.g. wrong cached
	  mail size). Fixes:
	  Panic: file index-mail-headers.c: line 198 (index_mail_parse_header_init):
	  assertion failed: (!mail->data.header_parser_initialized)
	- imap: v2.3.10 regression: When using INDEXPVT to enable private
	  \Seen flags (for shared or public namespaces) the STORE command did
	  not send untagged replies for the \Seen flag changes.
	- imap: v2.3.15 regression: If PREVIEW/SNIPPET is not the final FETCH
	  option in the command, the IMAP FETCH response is broken.
	- imap: v2.3.15 regression: MOVE command leaks mailbox if it can't be
	  opened and crashes at deinit:
	  Panic: file mail-user.c: line 229 (mail_user_deinit): assertion failed:
	  ((*user)->refcount == 1).
	- imapc: Copying nonexistent mail via imapc could have crashed. Fixes:
	  Panic: file mail-storage.c: line 2385 (mailbox_transaction_commit_get_changes):
	  assertion failed: (ret < 0 || seq_range_count(&changes_r->saved_uids) == save_count ||
	  array_count(&changes_r->saved_uids) == 0).
	- indexer: v2.3.15 regression: Process crashes if indexer-client
	  disconnects while it's waiting for command reply. This happened for
	  example if IMAP SEARCH triggered long fts indexing and the IMAP
	  client disconnected while waiting for the reply.
	- indexer: v2.3.15 regression: Process may have crashed in some situations.
	- indexer: v2.3.15 regression: indexer-worker processes may not have
	  reached the process_limit in some situations, possibly even using just
	  one indexer-worker process even though there were many indexing
	  requests queued.
	- lib-compression: Reading lz4 compressed mdbox mails may crash. Fixes:
	  Panic: file istream.c: line 345 (i_stream_read_memarea):
	  assertion failed: (!stream->blocking).
	- lib-compression: bench-compress crashes due to xz being read-only.
	- lib-lua: Fix linking libdict_lua for non-GNU linkers when Lua support
	  is disabled.
	- lib-mail: There was no limit on how large an email header name could be.
	  Processable header names are now limited to 1000 bytes.
	- lib-oauth2: Dovecot disallowed JWT tokens if their validity time was
	  older than token creation time (nbf < iat).
	- lib-storage: Reduce memory footprint of certain storage operations.
	- lib-storage: When listing mailboxes with storage name escape
	  characters (^ or .) as part of the mailbox name, the listing could
	  show corrupted mailbox names. Due to an issue in handling escaped
	  parent folders, the listing of other mailbox names would become
	  corrupted by prepending parts of the previously listed mailboxes
	  parent folder as prefix to the actual mailbox names. The corruption
	  can occur when using LAYOUT=INDEX and maildir or obox, or when using
	  the listescape plugin.
	- mail-crypt: Fix "-O" argument for "doveadm mailbox cryptokey password"
	  command to be a boolean, and not expect a string.
	- submission-login: Add support for not authenticating to next hop in
	  submission proxying.
	- submission-login: EHLO was not sent again after XCLIENT when doing
	  submission proxying.
	- virtual: Mailboxes do not correctly detect underlying mailboxes
	  getting re-created even though they have a different UIDVALIDITY or
	  GUID.

v2.3.16 2021-08-06  Timo Sirainen <timo.sirainen@open-xchange.com>

	* Any unexpected exit() will now result in a core dump. This can
	  especially help notice problems when a Lua script causes exit(0).
	* auth-worker process is now restarted when the number of auth
	  requests reaches service auth-worker { service_count }. The default
	  is still unlimited.

	+ Event improvements: Added data_stack_grow event and http-client
	  category. See https://doc.dovecot.org/admin_manual/list_of_events/
	+ oauth2: Support RFC 7628 openid-configuration element. This allows
	  clients to support OAUTH2 for any server, not just a few hardcoded
	  servers like they do now. See openid_configuration_url setting in
	  dovecot-oauth2.conf.ext.
	+ mysql: Single statements are no longer enclosed with BEGIN/COMMIT.
	+ dovecot-sysreport --core supports multiple core files now and does
	  not require specifying the binary path.
	+ imapc: When imap_acl plugin is loaded and imapc_features=acl is used,
	  IMAP ACL commands are proxied to the remote server. See
	  https://doc.dovecot.org/configuration_manual/mail_location/imapc/
	+ dict-sql now supports the "UPSERT" syntax for SQLite and PostgreSQL.
	+ imap: If IMAP client disconnects during a COPY command, the copying
	  is aborted, and changes are reverted. This may help to avoid many
	  email duplicates if client disconnects during COPY and retries it
	  after reconnecting.
	- master process was using 100% CPU if service attempted to create more
	  processes due to process_min_avail, but process_limit was already
	  reached. v2.3.15 regression.
	- Using attachment detection flags wrongly logged unnecessary "Failed
	  to add attachment keywords" errors. v2.3.13 regression.
	- IMAP QRESYNC: Expunging UID 1 mail resulted in broken VANISHED
	  response, which could have confused IMAP clients. v2.3.13 regression.
	- imap: STORE didn't send untagged replies for \Seen changes for
	  (shared) mailboxes using INDEXPVT. v2.3.10 regression.
	- rawlog_dir setting would not log input that was pipelined after
	  authentication command.
	- Fixed potential infinite looping with autoexpunging.
	- Log event exporter: Truncate long fields to 1000 bytes
	- LAYOUT=index: ACL inheritance didn't work when creating mailboxes
	- Event filters: Unquoted '?' wildcard caused a crash at startup
	- fs-metawrap: Fix to handling zero sized files
	- imap-hibernate: Fixed potential crash at deinit.
	- acl: dovecot-acl-list files were written for acl_ignore_namespaces
	- program-client (used by Sieve extprograms, director_flush_socket)
	  may have missed status response from UNIX and network sockets,
	  resulting in unexpected failures.

v2.3.15 2021-06-21  Aki Tuomi <aki.tuomi@open-xchange.com>

	* CVE-2021-29157: Dovecot does not correctly escape kid and azp fields in
	  JWT tokens. This may be used to supply attacker controlled keys to
	  validate tokens, if attacker has local access.
	* CVE-2021-33515: On-path attacker could have injected plaintext commands
	  before STARTTLS negotiation that would be executed after STARTTLS
	  finished with the client.
	* Disconnection log messages are now more standardized across services.
	  They also always now start with "Disconnected" prefix.
	* Dovecot now depends on libsystemd for systemd integration.
	* Removed support for Lua 5.2. Use version 5.1 or 5.3 instead.
	* config: Some settings are now marked as "hidden". It's discouraged to
	  change these settings. They will no longer be visible in doveconf
	  output, except if they have been changed or if doveconf -s parameter
	  is used. See https://doc.dovecot.org/settings/advanced/ for details.
	* imap-compress: Compression level is now algorithm specific.
	  See https://doc.dovecot.org/settings/plugin/compress-plugin/
	* indexer-worker: Convert "Indexed" info logs to an event named
	  "indexer_worker_indexing_finished". See
	  https://doc.dovecot.org/admin_manual/list_of_events/#indexer-worker-indexing-finished
	+ Add TSLv1.3 support to min_protocols.
	+ Allow configuring ssl_cipher_suites. (for TLSv1.3+)
	+ acl: Add acl_ignore_namespace setting which allows to entirely ignore
	  ACLs for the listed namespaces.
	+ imap: Support official RFC8970 preview/snippet syntax. Old methods of
	  retrieving preview information via IMAP commands ("SNIPPET and PREVIEW
	  with explicit algorithm selection") have been deprecated.
	+ imapc: Support INDEXPVT for imapc storage to enable private
	  message flags for cluster wide shared mailboxes.
	+ lib-storage: Add new events: mail_opened, mail_expunge_requested,
	  mail_expunged, mail_cache_lookup_finished. See
	  https://doc.dovecot.org/admin_manual/list_of_events/#mail
	+ zlib, imap-compression, fs-compress: Support compression levels that
	  the algorithm supports. Before, we would allow hardcoded value between
	  1 to 9 and would default to 6. Now we allow using per-algorithm value
	  range and default to whatever default the algorithm specifies.
	- *-login: Commands pipelined together with and just after the authenticate
	  command cause these commands to be executed twice. This applies to all
	  protocols that involve user login, which currently comprises of imap,
	  pop3, submisision and managesieve.
	- *-login: Processes are supposed to disconnect the oldest non-logged in
	  connection when process_limit was reached. This didn't actually happen
	  with the default "high-security mode" (with service_count=1) where each
	  connection is handled by a separate process.
	- *-login: When login process reaches client/process limits, oldest
	  client connections are disconnected. If one of these was still doing
	  anvil lookup, this caused a crash. This could happen only if the login
	  process limits were very low or if the server was overloaded.
	- Fixed building with link time optimizations (-flto).
	- auth: Userdb iteration with passwd driver does not always return all
	  users with some nss drivers.
	- dsync: Shared INBOX not synced when "mail_shared_explicit_inbox" was
	  disabled. If a user has a shared mailbox which is another user's INBOX,
	  dsync didn't include the mailbox in syncing unless explicit naming is
	  enabled with "mail_shared_explicit_inbox" set to "yes".
	- dsync: Shared namespaces were not synced with "-n" flag.
	- dsync: Syncing shared INBOX failed if mail_attribute_dict was not set.
	  If a user has a shared mailbox that is another user's INBOX, dsync
	  failed to export the mailbox if mail attributes are disabled.
	- fts-solr, fts-tika: Using both Solr FTS and Tika may have caused HTTP
	  requests to assert-crash: Panic: file http-client-request.c: line 1232
	  (http_client_request_send_more): assertion failed: (req->payload_input != NULL)
	- fts-tika: 5xx errors returned by Tika server as indexing failures.
	  However, Tika can return 5xx for some attachments every time.
	  So the 5xx error should be retried once, but treated as success if it
	  happens on the retry as well. v2.3 regression.
	- fts-tika: v2.3.11 regression: Indexing messages with fts-tika may have
	  resulted in Panic: file message-parser.c: line 802 (message_parser_deinit_from_parts):
	  assertion failed: (ctx->nested_parts_count == 0 || i_stream_have_bytes_left(ctx->input))
	- imap: SETMETADATA could not be used to unset metadata values.
	  Instead NIL was handled as a "NIL" string. v2.3.14 regression.
	- imap: IMAP BINARY FETCH crashes at least on empty base64 body:
	  Panic: file index-mail-binary.c: line 358 (blocks_count_lines):
	  assertion failed: (block_count == 0 || block_idx+1 == block_count)
	- imap: If IMAP client using the NOTIFY command was disconnected while
	  sending FETCH notifications to the client, imap could crash with
	  Panic: Trying to close mailbox INBOX with open transactions.
	- imap: Using IMAP COMPRESS extension can cause IMAP connection to hang
	  when IMAP commands are >8 kB long.
	- imapc: If remote server sent BYE but didn't immediately disconnect, it
	  could cause infinite busy-loop.
	- lib-index: Corrupted cache record size in dovecot.index.cache file
	  could have caused a crash (segfault) when accessing it.
	- lib-oauth2: JWT token time validation now works correctly with
	  32-bit systems.
	- lib-ssl-iostream: Checking hostnames against an SSL certificate was
	  case-sensitive.
	- lib-storage: Corrupted mime.parts in dovecot.index.cache may have
	  resulted in Panic: file imap-bodystructure.c: line 206 (part_write_body):
	  assertion failed: (text == ((part->flags & MESSAGE_PART_FLAG_TEXT) != 0))
	- lib-storage: Index rebuilding (e.g. via doveadm force-resync) didn't
	  preserve the "hdr-pop3-uidl" header. Because of this, the next pop3
	  session could have accessed all of the emails' metadata to read their
	  POP3 UIDL (opening dbox files).
	- listescape: When using the listescape plugin and a shared namespace
	  the plugin didn't work properly anymore resulting in errors like:
	  "Invalid mailbox name: Name must not have '/' character."
	- lmtp: Connection crashes if connection gets disconnected due to
	  multiple bad commands and the last bad command is BDAT.
	- lmtp: The Dovecot-specific LMTP parameter XRCPTFORWARD was blindly
	  forwarded by LMTP proxy without checking that the backend has support.
	  This caused a command parameter error from the backend if it was
	  running an older Dovecot release. This could only occur in more complex
	  setups where the message was proxied twice; when the proxy generated
	  the XRCPTFORWARD parameter itself the problem did not occur, so this
	  only happened when it was forwarded.
	- lmtp: The LMTP proxy crashes with a panic when the remote server
	  replies with an error while the mail is still being forwarded through
	  a DATA/BDAT command.
	- lmtp: Username may have been missing from lmtp log line prefixes when
	  it was performing autoexpunging.
	- master: Dovecot would incorrectly fail with haproxy 2.0.14 service
	  checks.
	- master: Systemd service: Dovecot announces readiness for accepting
	  connections earlier than it should. The following environment variables
	  are now imported automatically and can be omitted from
	  import_environment setting: NOTIFY_SOCKET LISTEN_FDS LISTEN_PID.
	- master: service { process_min_avail } was launching processes too
	  slowly when master was forking a lot of processes.
	- util: Make the health-check.sh example script POSIX shell compatible.

v2.3.14.1 2021-06-21  Aki Tuomi <aki.tuomi@open-xchange.com>

	* CVE-2021-29157: Dovecot does not correctly escape kid and azp fields in
	  JWT tokens. This may be used to supply attacker controlled keys to
	  validate tokens, if attacker has local access.
	* CVE-2021-33515: On-path attacker could have injected plaintext commands
	  before STARTTLS negotiation that would be executed after STARTTLS
	  finished with the client.
	- lib-index: Corrupted mime.parts in dovecot.index.cache may have
	  resulted in Panic: file imap-bodystructure.c: line 206 (part_write_body):
	  assertion failed: (text == ((part->flags & MESSAGE_PART_FLAG_TEXT) != 0))
	- imap: SETMETADATA could not be used to unset metadata values.
	  Instead NIL was handled as a "NIL" string. v2.3.14 regression.

V2.3.14 2021-03-04  Aki Tuomi <aki.tuomi@open-xchange.com>

	* Added new aliases for some variables. Usage of the old ones is possible,
	  but discouraged. (These were partially added already to v2.3.13.)
	  See https://doc.dovecot.org/configuration_manual/config_file/config_variables/
	  for more information.
	* Optimize imap/pop3/submission/managesieve proxies to use less CPU at
	  the cost of extra memory usage.
	* Remove autocreate, expire, snarf and mail-filter plugins.
	* Remove cydir storage driver.
	* Remove XZ/LZMA write support. Read support will be removed in future release.
	* doveadm -D: Add timestamps to debug output even when LOG_STDERR_TIMESTAMP
	  environment variable is not set. Timestamp format is taken from
	  log_timestamp setting.
	* If BROKENCHAR or listescape plugin is used, the escaped folder names
	  may be slightly different from before in some situations. This is
	  unlikely to cause issues, although caching clients may redownload the
	  folders.
	* imapc: It now enables BROKENCHAR=~ by default to escape remote folder
	  names if necessary. This also means that if there are any '~'
	  characters in the remote folder names, they will be visible as "~7e".
	* imapc: When using local index files folder names were escaped on
	  filesystem a bit differently. This affects only if there are folder
	  names that actually require escaping, which isn't so common. The old
	  style folders will be automatically deleted from filesystem.
	* stats: Update exported metrics to be compliant with OpenMetrics standard.
	+ doveadm: Add an optional '-p' parameter to metadata list command. If
	  enabled, "/private", and "/shared" metadata prefixes will be prepended
	  to the keys in the list output.
	+ doveconf: Support environment variables in config files. See
	  https://doc.dovecot.org/configuration_manual/config_file/config_file_syntax/#environment-variables
	  for more details.
	+ indexer-worker: Change indexer to disconnect from indexer-worker
	  after each request. This allows service indexer-worker's service_count &
	  idle_kill settings to work. These can be used to restart indexer-worker
	  processes once in a while to reduce their memory usage.
	- auth: "nodelay" with various authentication mechanisms such as apop
	  and digest-md5 crashed AUTH process if authentication failed.
	- auth: Auth lua script generating an error triggered an assertion
	  failure: Panic: file db-lua.c: line 630 (auth_lua_call_password_verify):
	  assertion failed: (lua_gettop(script->L) == 0).
	- configure: Fix libunwind detection to work on other than x86_64 systems.
	- doveadm-server: Process could crash if logging was done outside command
	  handling. For example http-client could have done debug logging
	  afterwards, resulting in either segfault or Panic:
	  file http-client.c: line 642 (http_client_context_close):
	  assertion failed: (cctx->clients_list == NULL).
	- dsync: Folder name escaping with BROKENCHAR didn't work completely
	  correctly. This especially caused problems with dsync-migrations using
	  imapc where some of the remote folder names may not have been accessible.
	- dsync: doveadm sync + imapc doesn't always sync all mails when doing
	  an incremental sync (-1), which could lead to mail loss when it's used
	  for migration. This happens only when GUIDs aren't used (i.e.
	  imapc without imapc_features=guid-forced).
	- fts-tika: When tika server returns error, some mails cause Panic:
	  file message-parser.c: line 802 (message_parser_deinit_from_parts):
	  assertion failed: (ctx->nested_parts_count == 0 || i_stream_have_bytes_left(ctx->input))
	- lib-imap: imapc parsing illegal BODYSTRUCTUREs with NILs could have
	  resulted in crashes. This exposed that Dovecot was wrongly accepting
	  atoms in "nstring" handling. Changed the IMAP parsing to be more
	  strict about this now.
	- lib-index: If dovecot.index.cache has corrupted message size, fetching
	  BODY/BODYSTRUCTURE may cause assert-crash:
	  Panic: file index-mail.c: line 1140 (index_mail_parse_body_finish):
	  assertion failed: (mail->data.parts != NULL).
	- lib-index: Minor error handling and race condition fixes related to
	  rotating dovecot.index.log. These didn't usually cause problems,
	  unless the log files were rotated rapidly.
	- lib-lua: Lua scripts using coroutines or lua libraries using coroutines
	  (e.g., cqueues) panicked.
	- Message PREVIEW handled whitespace wrong so first space would get
	  eaten from between words.
	- FTS and message PREVIEW (snippet) parsed HTML &entities case-sensitively.
	- lib-mail: When max nested MIME parts were reached, IMAP BODYSTRUCTURE
	  was written in a way that may have caused confusion for IMAP clients
	  and also Dovecot itself when parsing it. The truncated part is now
	  written out using application/octet-stream MIME type.
	- lib-oauth2: HS512 and HS384 JWT token algorithms crash when you try to
	  use them: Panic: file hmac.c: line 26 (hmac_init): assertion failed:
	  (meth->context_size <= MAC_MAX_CONTEXT_SIZE).
	- event filters: NOT keyword did not have the correct associativity.
	  NOT a AND b were getting parsed as NOT (a AND b) instead of
	  (NOT a) AND b.
	- Ignore ECONNRESET when closing socket. This avoids logging useless
	  errors on systems like FreeBSD.
	- event filters: event filter syntax error may lead to Panic:
	  file event-filter.c: line 137 (event_filter_parse): assertion failed:
	  (state.output == NULL)
	- lib: timeval_cmp_margin() was broken on 32-bit systems. This could
	  potentially have caused HTTP timeouts to be handled incorrectly.
	- log: instance_name wasn't used as syslog ident by the log process.
	- master: After a service reached process_limit and client_limit, it
	  could have taken up to 1 second to realize that more client connections
	  became available. During this time client connections could have been
	  unnecessarily rejected and a warning logged:
	  Warning: service(...): process_limit (...) reached, client connections are being dropped
	- stats: Crash would occur when generating openmetrics data for metrics
	  using aggregating functions.
	- stats: Event filters comparing against empty strings crash the stats
	  process.

v2.3.13 2021-01-04	Aki Tuomi <aki.tuomi@open-xchange.com>

	* CVE-2020-24386: Specially crafted command can cause IMAP hibernate to
	  allow logged in user to access other people's emails and filesystem
	  information.
	* Metric filter and global event filter variable syntax changed to a
	  SQL-like format. See https://doc.dovecot.org/configuration_manual/event_filter/
	* auth: Added new aliases for %{variables}. Usage of the old ones is
	  possible, but discouraged.
	* auth: Removed RPA auth mechanism, SKEY auth mechanism, NTLM auth
	  mechanism and related password schemes.
	* auth: Removed passdb-sia, passdb-vpopmail and userdb-vpopmail.
	* auth: Removed postfix postmap socket
	+ auth: Added new fields for auth server events. These fields are now
	  also available for all auth events. See
	  https://doc.dovecot.org/admin_manual/list_of_events/#authentication-server
	  for details.
	+ imap-hibernate: Added imap_client_hibernated, imap_client_unhibernated
	  and imap_client_unhibernate_retried events. See
	  https://doc.dovecot.org/admin_manual/list_of_events/ for details.
	+ lib-index: Added new mail_index_recreated event. See
	  https://doc.dovecot.org/admin_manual/list_of_events/#mail-index-recreated
	+ lib-sql: Support TLS options for cassandra driver. This requires
	  cpp-driver v2.15 (or later) to work reliably.
	+ lib-storage: Missing $HasAttachment / $HasNoAttachment flags are now
	  added to existing mails if mail_attachment_detection_option=add-flags
	  and it can be done inexpensively.
	+ login proxy: Added login_proxy_max_reconnects setting (default 3) to
	  control how many reconnections are attempted.
	+ login proxy: imap/pop3/submission/managesieve proxying now supports
	  reconnection retrying on more than just connect() failure. Any error
	  except a non-temporary authentication failure will result in reconnect
	  attempts.
	- auth: Lua passdb/userdb leaks stack elements per call, eventually
	  causing the stack to become too deep and crashing the auth or
	  auth-worker process.
	- auth: SASL authentication PLAIN mechanism could be used to trigger
	  read buffer overflow. However, this doesn't seem to be exploitable in
	  any way.
	- auth: v2.3.11 regression: GSSAPI authentication fails because dovecot
	  disallows NUL bytes for it.
	- dict: Process used too much CPU when iterating keys, because each key
	  used a separate write() syscall.
	- doveadm-server: Crash could occur if logging was done outside command
	  handling. For example http-client could have done debug logging
	  afterwards, resulting in either segfault or
	  Panic: file http-client.c: line 642 (http_client_context_close):
	  assertion failed: (cctx->clients_list == NULL).
	- doveadm-server: v2.3.11 regression: Trying to connect to doveadm server
	  process via starttls assert-crashed if there were no ssl=yes listeners:
	  Panic: file master-service-ssl.c: line 22 (master_service_ssl_init):
	  assertion failed: (service->ssl_ctx_initialized).
	- fts-solr: HTTP requests may have assert-crashed:
	  Panic: file http-client-request.c: line 1232 (http_client_request_send_more):
	  assertion failed: (req->payload_input != NULL)
	- imap: IMAP NOTIFY could crash with a segmentation fault due to a bad
	  configuration that causes errors. Sending the error responses to the
	  client can cause the segmentation fault. This can for example happen
	  when several namespaces use the same mail storage location.
	- imap: IMAP NOTIFY used on a shared namespace that doesn't actually
	  exist (e.g. public namespace for a nonexistent user) can crash with a panic:
	  Panic: Leaked view for index /tmp/home/asdf/mdbox/dovecot.list.index: Opened in (null):0
	- imap: IMAP session can crash with QRESYNC extension if many changes
	  are done before asking for expunged mails since last sync.
	- imap: Process might hang indefinitely if client disconnects after
	  sending some long-running commands pipelined, for example FETCH+LOGOUT.
	- lib-compress: Mitigate crashes when configuring a not compiled in
	  compression. Errors with compression configuration now distinguish
	  between not supported and unknown.
	- lib-compression: Using xz/lzma compression in v2.3.11 could have
	  written truncated output in some situations. This would result in
	  "Broken pipe" read errors when trying to read it back.
	- lib-compression: zstd compression could have crashed in some situations:
	  Panic: file ostream.c: line 287 (o_stream_sendv_int): assertion failed: (!stream->blocking)
	- lib-dict: dict client could have crashed in some rare situations when
	  iterating keys.
	- lib-http: Fix several assert-crashes in HTTP client.
	- lib-index: v2.3.11 regression: When mails were expunged at the same
	  time as lots of new content was being saved to the cache (e.g. cache
	  file was lost and is being re-filled) a deadlock could occur with
	  dovecot.index.cache / dovecot.index.log.
	- lib-index: v2.3.11 regression: dovecot.index.cache file was being
	  purged (rewritten) too often when it had a field that hadn't been
	  accessed for over 1 month, but less than 2 months. Every cache file
	  change caused a purging in this situation.
	- lib-mail: MIME parts were not returned correctly by Dovecot MIME parser.
	  Regression caused by fixing CVE-2020-12100.
	- lib-mail: When max nested MIME parts were reached, IMAP BODYSTRUCTURE
	  was written in a way that may have caused confusion for both IMAP
	  clients and Dovecot itself when parsing it. The truncated part is now
	  written out using application/octet-stream MIME type.
	- lib-mail: v2.3.11 regression: Mail delivery / parsing crashed when the
	  10000th MIME part was message/rfc822 (or if parent was multipart/digest):
	  Panic: file message-parser.c: line 167 (message_part_append):
	  assertion failed: (ctx->total_parts_count <= ctx->max_total_mime_parts).
	- lib-oauth2: Dovecot incorrectly required oauth2 server introspection
	  reply to contain username with invalid token.
	- lib-ssl-iostream, lib-dcrypt: Fix building with OpenSSL that has
	  deprecated APIs disabled.
	- lib-storage: When mail's size is different from the cached one (in
	  dovecot.index.cache or Maildir S=size in the filename), this is
	  handled by logging "Cached message size smaller/larger than expected"
	  error. However, in some situations this also ended up crashing with:
	  Panic: file istream.c: line 315 (i_stream_read_memarea):
	  assertion failed: (old_size <= _stream->pos - _stream->skip).
	- lib-storage: v2.3 regression: Copying/moving mails was taking much more
	  memory than before. This was mainly visible when copying/moving
	  thousands of mails in a single transaction.
	- lib-storage: v2.3.11 regression: Searching messages assert-crashed
	  (without FTS): Panic: file message-parser.c: line 174 (message_part_finish):
	  assertion failed: (ctx->nested_parts_count > 0).
	- lib: Dovecot v2.3 moved signal handlers around in ioloops,
	  causing more CPU usage than in v2.2.
	- lib: Fixed JSON parsing: '\' escape sequence may have wrongly resulted
	  in error if it happened to be at read boundary. Any NUL characters and
	  '\u0000' will now result in parsing error instead of silently
	  truncating the data.
	- lmtp, submission: Server may hang if SSL client connection disconnects
	  during the delivery. If this happened repeated, it could have ended
	  up reaching process_limit and preventing any further lmtp/submission
	  deliveries.
	- lmtp: Proxy does not always properly log TLS connection problems as
	  errors; in some cases, only a debug message is logged if enabled.
	- lmtp: The LMTP service can hang when commands are pipelined. This can
	  particularly occur when one command in the middle of the pipeline fails.
	  One example of this occurs for proxied LMTP transactions in which the
	  final DATA or BDAT command is pipelined after a failing RCPT command.
	- login-proxy: The login_source_ips setting has no effect, and therefore
	  the proxy source IPs are not cycled through as they should be.
	- master: Process was using 100% CPU in some situations when a broken
	  service was being throttled.
	- pop3-login: POP3 login would fail with "Input buffer full" if the
	  initial response for SASL was too long.
	- stats: Crash would occur when generating openmetrics data for metrics
	  using aggregating functions.

v2.3.11.3 2020-07-29	Aki Tuomi <aki.tuomi@open-xchange.com>

	- pop3-login: Login didn't handle commands in multiple IP packets properly.
	  This mainly affected large XCLIENT commands or a large SASL initial
	  response parameter in the AUTH command.
	- pop3: pop3_deleted_flag setting was broken, causing:
	  Panic: file seq-range-array.c: line 472 (seq_range_array_invert):
	  assertion failed: (range[count-1].seq2 <= max_seq)

v2.3.11.2 2020-07-13	Aki Tuomi <aki.tuomi@open-xchange.com>

	- auth: Lua passdb/userdb leaks stack elements per call, eventually
	  causing the stack to become too deep and crashing the auth or
	  auth-worker process.
	- lib-mail: v2.3.11 regression: MIME parts not returned correctly by
	  Dovecot MIME parser.
	- pop3-login: Login would fail with "Input buffer full" if the initial
	  response for SASL was too long.

v2.3.11 2020-06-17  Aki Tuomi <aki.tuomi@open-xchange.com>

	* CVE-2020-12100: Parsing mails with a large number of MIME parts could
	  have resulted in excessive CPU usage or a crash due to running out of
	  stack memory.
	* CVE-2020-12673: Dovecot's NTLM implementation does not correctly check
	  message buffer size, which leads to reading past allocation which can
	  lead to crash.
	* CVE-2020-10967: lmtp/submission: Issuing the RCPT command with an
	  address that has the empty quoted string as local-part causes the lmtp
	  service to crash.
	* CVE-2020-12674: Dovecot's RPA mechanism implementation accepts
	  zero-length message, which leads to assert-crash later on.
	* Events: Fix inconsistency in events. See event documentation in
	  https://doc.dovecot.org.
	* imap_command_finished event's cmd_name field now contains "unknown"
	  for unknown commands. A new "cmd_input_name" field contains the
	  command name exactly as it was sent.
	* lib-index: Renamed mail_cache_compress_* settings to mail_cache_purge_*.
	  Note that these settings are mainly intended for testing and usually
	  shouldn't be changed.
	* events: Renamed "index" event category to "mail-index".
	* events: service:<name> category is now using the name from
	  configuration file.
	* dns-client: service dns_client was renamed to dns-client.
	* log: Prefixes generally use the service name from configuration file.
	  For example dict-async service will now use
	  "dict-async(pid): " log prefix instead of "dict(pid): "
	* *-login: Changed logging done by proxying to use a consistent prefix
	  containing the IP address and port.
	* *-login: Changed disconnection log messages to be slightly clearer.
	+ dict: Add events for dictionaries.
	+ lib-index: Finish logging with events.
	+ oauth2: Support local validation of JWT tokens.
	+ stats: Add support for dynamic histograms and grouping. See
	  https://doc.dovecot.org/configuration_manual/stats/.
	+ imap: Implement RFC 8514: IMAP SAVEDATE
	+ lib-index: If a long-running transaction (e.g. SORT/FETCH on a huge
	  folder) adds a lot of data to dovecot.index.cache file, commit those
	  changes periodically to make them visible to other concurrent sessions
	  as well.
	+ stats: Add OpenMetrics exporter for statistics. See
	  https://doc.dovecot.org/configuration_manual/stats/openmetrics/.
	+ stats: Support disabling stats-writer socket by setting
	  stats_writer_socket_path="".
	- auth-worker: Process keeps slowly increasing its memory usage and
	  eventually dies with "out of memory" due to reaching vsz_limit.
	- auth: Prevent potential timing attacks in authentication secret
	  comparisons: OAUTH2 JWT-token HMAC, imap-urlauth token, crypt() result.
	- auth: Several auth-mechanisms allowed input to be truncated by NUL
	  which can potentially lead to unintentional issues or even successful
	  logins which should have failed.
	- auth: When auth policy returned a delay, auth_request_finished event
	  had policy_result=ok field instead of policy_result=delayed.
	- auth: auth process crash when auth_policy_server_url is set to an
	  invalid URL.
	- dict-ldap: Crash occurs if var_expand template expansion fails.
	- dict: If dict client disconnected while iteration was still running,
	  dict process could have started using 100% CPU, although it was still
	  handling clients.
	- doveadm: Running doveadm commands via proxying may hang, especially
	  when doveadm is printing a lot of output.
	- imap: "MOVE * destfolder" goes to a loop copying the last mail to the
	  destination until the imap process dies due to running out of memory.
	- imap: Running "UID MOVE 1:* Trash" on an empty folder goes to infinite
	  loop.
	- imap: SEARCH doesn't support $.
	- lib-compress: Buffer over-read in zlib stream read.
	- lib-dns: If DNS lookup times out, lib-dns can cause crash in calling
	  process.
	- lib-index: Fixed several bugs in dovecot.index.cache handling that
	  could have caused cached data to be lost.
	- lib-index: Writing to >=1 GB dovecot.index.cache files may cause
	  assert-crashes:
	  Panic: file mail-index-util.c: line 37 (mail_index_uint32_to_offset):
	  assertion failed: (offset < 0x40000000)
	- lib-ssl-iostream: Fix buggy OpenSSL error handling without
	  assert-crashing. If there is no error available, log it as an error
	  instead of crashing:
	  Panic: file iostream-openssl.c: line 599 (openssl_iostream_handle_error):
	  assertion failed: (errno != 0)
	- lib-ssl-iostream: ssl_key_password setting did not work.
	- submission: A segfault crash may occur when the client or server
	  disconnects while a non-transaction command like NOOP or VRFY is still
	  being processed.
	- virtual: Copying/moving mails with IMAP into a virtual folder assert-crashes:
	  Panic: file cmd-copy.c: line 152 (fetch_and_copy): assertion failed:
	  (copy_ctx->copy_count == seq_range_count(&copy_ctx->saved_uids))

v2.3.10  2020-03-06  Aki Tuomi <aki.tuomi@open-xchange.com>

	* Disable retpoline migitations by default. These can cause severe
	  performance regressions, so they should be only enabled when
	  applicable.
	* IMAP MOVE now commits transactions in batches of 1000 mails. This
	  helps especially with lazy_expunge when moving a lot of mails. It
	  mainly avoids situations where multiple IMAP sessions are running the
	  same MOVE command and duplicating the mails in the lazy_expunge folder.
	  With this change there can still be some duplication, but the MOVE
	  always progresses forward. Also if the MOVE fails at some point, the
	  changes up to the last 1000 mails are still committed instead of
	  rolled back. Note that the COPY command behavior hasn't changed,
	  because it is required by IMAP standard to be an atomic operation.
	* IMAP EXPUNGE and CLOSE now expunges mails in batches of 1000 mails.
	  This helps especially with lazy_expunge when expunging a lot of mails
	  (e.g. millions) to make sure that the progress always moves forward
	  even if the process is killed.
	* Autoexpunging now expunges mails in batches of 1000 mails. This helps
	  especially with lazy_expunge when expunging a lot of mails
	  (e.g. millions) to make sure that the progress always moves forward
	  even if the process is killed.
	+ Add tool for generating sysreport called dovecot-sysreport.
	  This generates a bundle of information usually needed for support
	  requests.
	+ Add support for the new IMAP \Important SPECIAL-USE flag (RFC 8457).
	+ Add metric { group_by } setting. This allows automatically creating
	  new metrics based on the fields you want to group statistics by.
	  NOTE: This feature is considered experimental and syntax is subject
	  to change in future release.
	+ auth: Support SCRAM-SHA-256 authentication mechanism.
	+ imap: Support the new IMAP STATUS=SIZE extension.
	+ Use TCP_QUICKACK to reduce latency for some TCP connections.
	+ quota-status: Made the service more robust against erroneous use with
	  Postfix ACL policies other than smtpd_recipient_restrictions.
	+ Add "revision" field support to imap_id_send setting. Using
	  "revision *" will send in IMAP ID command response the short commit
	  hash of the Dovecot git source tree HEAD (same as in dovecot --version).
	+ IMAP ENVELOPE includes now all addresses when there are multiple
	  headers (From, To, Cc, etc.) The standard way of having multiple
	  addresses is to just list them all in a single header. It's
	  non-standard to have multiple headers. However, since MTAs allow these
	  mails to pass through and different software may handle them in
	  different ways, it's better from security point of view to show all
	  the addresses.
	+ Event filters now support using "field_name=" to match a field that
	  doesn't exist or has an empty value. For example use "error=" to match
	  only events that didn't fail.
	- acl: INBOX ACLs shouldn't apply for IMAP GETMETADATA/SETMETADATA
	  commands.
	- cassandra: CASS_ERROR_SERVER_WRITE_FAILURE error should also be
	  treated as "uncertain write failure".
	- dict-redis: Using quota_clone configured with dict-redis could have
	  crashed when Redis responded slowly.
	- imap-hibernate: Communication trouble with imap-master leads to
	  segfault.
	- imap-hibernate: Unhibernation retrying wasn't working.
	- imap: Fixed auth lookup privilege problem when imap process was reused
	  and user was being un-hibernated.
	- Fix potential crash when copying/moving mails within the same folder.
	  This happened only when there were a lot of fields in dovecot.index.cache.
	- lib-index: Recreating dovecot.index.cache file could have crashed when
	  merging bitmask fields.
	- lib-index: Using public/shared folders with INDEXPVT configured to use
	  private \Seen flags, trying to search seen/unseen in an empty folder
	  crashes with segfault.
	- lib-mail: Large base64-encoded mails weren't decoded properly.
	  This could have affected searching/indexing mails and message snippet
	  generation.
	- lib-mail: Message with only quoted text could have caused message
	  snippet to ignore its 200 character limit and return the entire
	  message. This was added also to dovecot.index.cache file, which
	  increased disk space and memory usage unnecessarily.
	  v2.3.9.2 regression (previous versions cached the quoted snippet as
	  empty). In a large mail quoted text could have become wrongly added
	  to the snippet, possibly mixed together with non-quoted text.
	- lib-smtp: client could have assert-crashed if STARTTLS handshake
	  finished earlier than usually.
	- lib-ssl-iostream: remove -static flag for lib-ssl-iostream linking to
	  prevent a compile issue.
	- lib-storage: Mailbox synchronization may have assert-crashed in some
	  rare situations.
	- lib-storage: mdbox didn't preserve date.saved with dsync.
	- lib: Don't require EAI_{ADDRFAMILY,NODATA}, breaks FreeBSD
	- master: Some services could respawn unthrottled if they crash during
	  startup.
	- push-notification: Do not send push_notification_finished event if
	  nothing was done. This happens when mail transaction is started and
	  ended with no changes.
	- quota-status: Addresses with special characters in the local part caused
	  problems in the interaction between Postfix and Dovecot. Postfix sent
	  its own internal representation in the recipient field, while Dovecot
	  expected a valid RFC5321 mailbox address.
	- submission-login: SESSION was not correctly encoded field for the
	  XCLIENT command. Particularly, a '+' character introduced by the
	  session ID's Base64 encoding causes problems.
	- submission: Fix submission_max_mail_size to work correctly on 32-bit
	  systems.
	- submission: Trusted connections crashed in second connection's EHLO
	  if submission-login { service_count } is something else than 1 (which
	  is the default).
	- submission: XCLIENT command was never used in the protocol exchange
	  with the relay MTA when submission_backend_capabilities is configured,
	  even when the relay MTA was properly configured to accept the XCLIENT
	  command.

v2.3.9.3 2020-02-12  Aki Tuomi <aki.tuomi@open-xchange.com>

	* CVE-2020-7046: Truncated UTF-8 can be used to DoS
	  submission-login and lmtp processes.
	* CVE-2020-7957: Specially crafted mail can crash snippet generation.

v2.3.9.2 2019-12-13  Aki Tuomi <aki.tuomi@open-xchange.com>

	- Mails with empty From/To headers can also cause crash
	  in push notification drivers.

v2.3.9.1 2019-12-13  Aki Tuomi <aki.tuomi@open-xchange.com>

	* CVE-2019-19722: Mails with group addresses in From or To fields
	  caused crash in push notification drivers.

v2.3.9 2019-12-04  Aki Tuomi <aki.tuomi@open-xchange.com>

	* Changed several event field names for consistency and to avoid
	  conflicts in parent-child event relationships:
	   * SMTP server command events: Renamed "name" to "cmd_name"
	   * Events inheriting from a mailbox: Renamed "name" to "mailbox"
	   * Server connection events have only "remote_ip", "remote_port",
	     "local_ip" and "local_port".
	   * Removed duplicate "client_ip", "ip" and "port".
	   * Mail storage events: Removed "service" field.
	     Use "service:<name>" category instead.
	   * HTTP client connection events: Renamed "host" to "dest_host" and
	     "port" to "dest_port"
	* auth: Drop Postfix socketmap support. It hasn't been working
	  with recent Postfix versions for a while now.
	* push-notification-lua: The "subject" field is now decoded to UTF8
	  instead of kept as MIME-encoded.
	+ push-notification-lua: Added new "from_address", "from_display_name",
	  "to_address" and "to_display_name" fields. The display names are
	  decoded to UTF8.
	+ Added various new fields to existing events.
	  See http://doc.dovecot.net/admin_manual/list_of_events.html
	+ Add lmtp_add_received_header setting. It can be used to prevent LMTP
	  from adding "Received:" headers.
	+ doveadm: Support SSL/STARTTLS for proxied doveadm connections based on
	  doveadm_ssl setting and proxy ssl/tls settings.
	+ Log filters support now "service:<name>", which matches all events for
	  the given service. It can also be used as a category.
	+ lib: Use libunwind to get abort backtraces with function names
	  where available.
	+ lmtp: When the LMTP proxy changes the username (from passdb lookup)
	  add an appropriate ORCPT parameter.
	- lmtp: Add lmtp_client_workarounds setting to implement workarounds for
	  clients that send MAIL and RCPT commands with additional spaces before
	  the path and for clients that omit <> brackets around the path.
	  See example-config/conf.d/20-lmtp.conf.
	- lda/lmtp: Invalid MAIL FROM addresses were rejcted too aggressively.
	  Now mails from addresses with unicode characters are delivered, but
	  their Return-Path header will be <> instead of the given MAIL FROM
	  address.
	- lmtp: The lmtp_hdr_delivery_address setting is ignored.
	- imap: imap_command_finished event's "args" and "human_args" parameters
	  were always empty.
	- mbox: Seeking in zlib and bzip2 compressed input streams didn't work
	  correctly.
	- imap-hibernate: Process crashed when client got destroyed while it was
	  attempted to be unhibernated, and the unhibernation fails.
	- *-login: Proxying may have crashed if SSL handshake to the backend
	  failed immediately. This was unlikely to happen in normal operation.
	- *-login: If TLS handshake to upstream server failed during proxying,
	  login process could crash due to invalid memory access.
	- *-login: v2.3 regression: Using SASL authentication without initial
	  response may have caused SSL connections to hang. This happened often
	  at least with PHP's IMAP library.
	- *-login: When login processes are flooded with authentication attempts
	  it starts logging errors about "Authentication server sent unknown id".
	  This is still expected. However, it also caused the login process to
	  disconnect from auth server and potentially log some user's password
	  in the error message.
	- dict-sql: SQL prepared statements were not shared between sessions.
	  This resulted in creating a lot of prepared statements, which was
	  especially inefficient when using Cassandra backend with a lot of
	  Cassandra nodes.
	- auth: auth_request_finished event didn't have success=yes parameter
	  set for successful authentications.
	- auth: userdb dict - Trying to list users crashed.
	- submission: Service could be configured to allow anonymous
	  authentication mechanism and anonymous user access.
	- LAYOUT=index: Corrupted dovecot.list.index caused folder creation to
	  panic.
	- doveadm: HTTP server crashes if request target starts with double "/".
	- dsync: Remote dsync started hanging if the initial doveadm
	  "dsync-server" command was sent in the same TCP packet as the
	  following dsync handshake. v2.3.8 regression.
	- lib: Several "input streams" had a bug that in some rare situations
	  might cause it to access freed memory. This could lead to crashes or
	  corruption.
	  The only currently known effect of this is that using zlib plugin with
	  external mail attachments (mail_attachment_dir) could cause fetching
	  the mail to return a few bytes of garbage data at the beginning of the
	  header. Note that the mail wasn't saved corrupted, but fetching it
	  caused corrupted mail to be sent to the client.
	- lib-storage: If a mail only has quoted content, use the quoted text
	  for generating message snippet (IMAP PREVIEW) instead of returning
	  empty snippet.
	- lib-storage: When vsize header was rebuilt, newly calculated message
	  sizes were added to dovecot.index.cache instead of being directly
	  saved into vsize records in dovecot.index.
	- lib: JSON generator was escaping UTF-8 characters unnecessarily.

v2.3.8 2019-10-08  Aki Tuomi <aki.tuomi@open-xchange.com>

	+ Added mail_delivery_started and mail_delivery_finished events, see
	  https://doc.dovecot.org/admin_manual/list_of_events/ for details.
	+ dsync-replication: Don't replicate users who have "noreplicate" extra
	  field in userdb.
	+ doveadm service status: Show total number of processes created.
	+ When logging to syslog, use instance_name setting's value for the
	  ident. This commonly is added as a log prefix.
	+ Base64 encoding/decoding code was rewritten with additional features.
	  It shouldn't cause any user visible changes.
	- v2.3.7 regression: If a folder only receives new mails without any
	  other mail access, dovecot.index.log keeps growing forever and
	  dovecot.index keeps being rewritten for every mail delivery.
	- dsync-replication may lose keywords after syncing mails restored from
	  another replica. This only happened if the mail only had keywords and
	  no system flags.
	- event filters: Non-textual event fields could not be filtered using
	  wildcards.
	- auth: Scope parameter was missing from OAuth password grant
	  request.
	- doveadm client-server communication may hang in some situations.
	  It is also using unnecessarily small TCP/IP packet sizes.
	- doveadm who and kick did not flush protocol output correctly.
	- imap: SETMETADATA with literal value would delete the metadata value
	  instead of updating it.
	- imap: When client issues FETCH PREVIEW (LAZY=FUZZY) command, the
	  caching decisions should be updated so that newly saved mails will
	  have the preview cached.
	- With mail_nfs_index=yes and/or mail_nfs_storage=yes setuid/setgid
	  permission bits in some files may have become dropped with some NFS
	  servers. Changed NFS flushing to now use chmod() instead of chown().
	- quota: warnings did not work if quota root was noenforcing
	- acl: Global ACL file ignored the last line if it didn't end with LF.
	- doveadm stats dump: With JSON formatter output numbers using the
	  number type instead of as strings
	- lmtp_proxy: Ensure that real_* variables are correctly set when using
	  lmtp_proxy.
	- event exporter: http-post driver had hardcoded timeout and did not
	  support DNS lookups or TLS connections.
	- auth: Fix user iteration to work with userdb passwd with glibc v2.28.
	- auth: auth service can crash if auth-policy JSON response is invalid
	  or returned too fast.
	- In some rare situations "ps" output could have shown a lot of "?"
	  characters after Dovecot process titles.
	- When dovecot.index.pvt is empty, an unnecessary error is logged:
	  Error: .../dovecot.index.pvt reset, view is now inconsistent
	- SMTP address encoder duplicated initial double quote character when
	  the localpart of an address ended in '..'. For example
	  "user+..@example.com" became ""user+.."@example.com in a
	  sieve redirect.

