-$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.498 2007/03/21 15:15:12 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.632 2010/06/12 15:21:25 jetmore Exp $
Change log file for Exim from version 4.21
-------------------------------------------
+Exim version 4.75
+-----------------
+
+NM/01 Workround for PCRE version dependency in version reporting
+ Bugzilla 1073
+
+TF/01 Update valgrind.h and memcheck.h to copies from valgrind-3.6.0.
+ This fixes portability to compilers other than gcc, notably
+ Solaris CC and HP-UX CC. Fixes Bugzilla 1050.
+
+TF/02 Bugzilla 139: Avoid using the += operator in the modular lookup
+ makefiles for portability to HP-UX and POSIX correctness.
+
+PP/01 Permit LOOKUP_foo enabling on the make command-line.
+ Also via indented variable definition in the Makefile.
+ (Debugging by Oliver Heesakkers).
+
+PP/02 Restore caching of spamd results with expanded spamd_address.
+ Patch from author of expandable spamd_address patch, Wolfgang Breyha.
+
+PP/03 Build issue: lookups-Makefile now exports LC_ALL=C
+ Improves build reliability. Fix from: Frank Elsner
+
+NM/02 Fix wide character breakage in the rfc2047 coding
+ Fixes bug 1064. Patch from Andrey N. Oktyabrski
+
+NM/03 Allow underscore in dnslist lookups
+ Fixes bug 1026. Patch from Graeme Fowler
+
+PP/04 Bugzilla 230: Support TLS-enabled LDAP (in addition to ldaps).
+ Code patches from Adam Ciarcinski of NetBSD.
+
+NM/04 Fixed exiqgrep to cope with mailq missing size issue
+ Fixes bug 943.
+
+PP/05 Bugzilla 1083: when lookup expansion defers, escape the output which
+ is logged, to avoid truncation. Patch from John Horne.
+
+PP/06 Bugzilla 1042: implement freeze_signal on pipe transports.
+ Patch from Jakob Hirsch.
+
+PP/07 Bugzilla 1061: restrict error messages sent over SMTP to not reveal
+ SQL string expansion failure details.
+ Patch from Andrey Oktyabrski.
+
+PP/08 Bugzilla 486: implement %M datestamping in log filenames.
+ Patch from Simon Arlott.
+
+PP/09 New lookups functionality failed to compile on old gcc which rejects
+ extern declarations in function scope.
+ Patch from Oliver Fleischmann
+
+PP/10 Use sig_atomic_t for flags set from signal handlers.
+ Check getgroups() return and improve debugging.
+ Fixed developed for diagnosis in bug 927 (which turned out to be
+ a kernel bug).
+
+PP/11 Bugzilla 1055: Update $message_linecount for maildir_tag.
+ Patch from Mark Zealey.
+
+PP/12 Bugzilla 1056: Improved spamd server selection.
+ Patch from Mark Zealey.
+
+PP/13 Bugzilla 1086: Deal with maildir quota file races.
+ Based on patch from Heiko Schlittermann.
+
+PP/14 Bugzilla 1019: DKIM multiple signature generation fix.
+ Patch from Uwe Doering, sign-off by Michael Haardt.
+
+NM/05 Fix to spam.c to accommodate older gcc versions which dislike
+ variable declaration deep within a block. Bug and patch from
+ Dennis Davis.
+
+
+Exim version 4.74
+-----------------
+
+TF/01 Failure to get a lock on a hints database can have serious
+ consequences so log it to the panic log.
+
+TF/02 Log LMTP confirmation messages in the same way as SMTP,
+ controlled using the smtp_confirmation log selector.
+
+TF/03 Include the error message when we fail to unlink a spool file.
+
+DW/01 Bugzilla 139: Support dynamically loaded lookups as modules.
+ With thanks to Steve Haslam, Johannes Berg & Serge Demonchaux
+ for maintaining out-of-tree patches for some time.
+
+PP/01 Bugzilla 139: Documentation and portability issues.
+ Avoid GNU Makefile-isms, let Exim continue to build on BSD.
+ Handle per-OS dynamic-module compilation flags.
+
+PP/02 Let /dev/null have normal permissions.
+ The 4.73 fixes were a little too stringent and complained about the
+ permissions on /dev/null. Exempt it from some checks.
+ Reported by Andreas M. Kirchwitz.
+
+PP/03 Report version information for many libraries, including
+ Exim version information for dynamically loaded libraries. Created
+ version.h, now support a version extension string for distributors
+ who patch heavily. Dynamic module ABI change.
+
+PP/04 CVE-2011-0017 - check return value of setuid/setgid. This is a
+ privilege escalation vulnerability whereby the Exim run-time user
+ can cause root to append content of the attacker's choosing to
+ arbitrary files.
+
+PP/05 Bugzilla 1041: merged DCC maintainer's fixes for return code.
+ (Wolfgang Breyha)
+
+PP/06 Bugzilla 1071: fix delivery logging with untrusted macros.
+ If dropping privileges for untrusted macros, we disabled normal logging
+ on the basis that it would fail; for the Exim run-time user, this is not
+ the case, and it resulted in successful deliveries going unlogged.
+ Fixed. Reported by Andreas Metzler.
+
+
+Exim version 4.73
+-----------------
+
+PP/01 Date: & Message-Id: revert to normally being appended to a message,
+ only prepend for the Resent-* case. Fixes regression introduced in
+ Exim 4.70 by NM/22 for Bugzilla 607.
+
+PP/02 Include check_rfc2047_length in configure.default because we're seeing
+ increasing numbers of administrators be bitten by this.
+
+JJ/01 Added DISABLE_DKIM and comment to src/EDITME
+
+PP/03 Bugzilla 994: added openssl_options main configuration option.
+
+PP/04 Bugzilla 995: provide better SSL diagnostics on failed reads.
+
+PP/05 Bugzilla 834: provide a permit_coredump option for pipe transports.
+
+PP/06 Adjust NTLM authentication to handle SASL Initial Response.
+
+PP/07 If TLS negotiated an anonymous cipher, we could end up with SSL but
+ without a peer certificate, leading to a segfault because of an
+ assumption that peers always have certificates. Be a little more
+ paranoid. Problem reported by Martin Tscholak.
+
+PP/08 Bugzilla 926: switch ClamAV to use the new zINSTREAM API for content
+ filtering; old API available if built with WITH_OLD_CLAMAV_STREAM=yes
+ NB: ClamAV planning to remove STREAM in "middle of 2010".
+ CL also introduces -bmalware, various -d+acl logging additions and
+ more caution in buffer sizes.
+
+PP/09 Implemented reverse_ip expansion operator.
+
+PP/10 Bugzilla 937: provide a "debug" ACL control.
+
+PP/11 Bugzilla 922: Documentation dusting, patch provided by John Horne.
+
+PP/12 Bugzilla 973: Implement --version.
+
+PP/13 Bugzilla 752: Refuse to build/run if Exim user is root/0.
+
+PP/14 Build without WITH_CONTENT_SCAN. Path from Andreas Metzler.
+
+PP/15 Bugzilla 816: support multiple condition rules on Routers.
+
+PP/16 Add bool_lax{} expansion operator and use that for combining multiple
+ condition rules, instead of bool{}. Make both bool{} and bool_lax{}
+ ignore trailing whitespace.
+
+JJ/02 prevent non-panic DKIM error from being sent to paniclog
+
+JJ/03 added tcp_wrappers_daemon_name to allow host entries other than
+ "exim" to be used
+
+PP/17 Fix malware regression for cmdline scanner introduced in PP/08.
+ Notification from Dr Andrew Aitchison.
+
+PP/18 Change ClamAV response parsing to be more robust and to handle ClamAV's
+ ExtendedDetectionInfo response format.
+ Notification from John Horne.
+
+PP/19 OpenSSL 1.0.0a compatibility const-ness change, should be backwards
+ compatible.
+
+PP/20 Added a CONTRIBUTING file. Fixed the documentation build to use http:
+ XSL and documented dependency on system catalogs, with examples of how
+ it normally works.
+
+DW/21 Added Valgrind hooks in store.c to help it capture out-of-bounds store
+ access.
+
+DW/22 Bugzilla 1044: CVE-2010-4345 - partial fix: restrict default behaviour
+ of CONFIGURE_OWNER and CONFIGURE_GROUP options to no longer allow a
+ configuration file which is writeable by the Exim user or group.
+
+DW/23 Bugzilla 1044: CVE-2010-4345 - part two: extend checks for writeability
+ of configuration files to cover files specified with the -C option if
+ they are going to be used with root privileges, not just the default
+ configuration file.
+
+DW/24 Bugzilla 1044: CVE-2010-4345 - part three: remove ALT_CONFIG_ROOT_ONLY
+ option (effectively making it always true).
+
+DW/25 Add TRUSTED_CONFIG_PREFIX_FILE option to allow alternative configuration
+ files to be used while preserving root privileges.
+
+DW/26 Set FD_CLOEXEC on SMTP sockets after forking in the daemon, to ensure
+ that rogue child processes cannot use them.
+
+PP/27 Bugzilla 1047: change the default for system_filter_user to be the Exim
+ run-time user, instead of root.
+
+PP/28 Add WHITELIST_D_MACROS option to let some macros be overriden by the
+ Exim run-time user without dropping privileges.
+
+DW/29 Remove use of va_copy() which breaks pre-C99 systems. Duplicate the
+ result string, instead of calling string_vformat() twice with the same
+ arguments.
+
+DW/30 Allow TRUSTED_CONFIG_PREFIX_FILE only for Exim or CONFIGURE_OWNER, not
+ for other users. Others should always drop root privileges if they use
+ -C on the command line, even for a whitelisted configure file.
+
+DW/31 Turn TRUSTED_CONFIG_PREFIX_FILE into TRUSTED_CONFIG_FILE. No prefixes.
+
+NM/01 Fixed bug #1002 - Message loss when using multiple deliveries
+
+
+Exim version 4.72
+-----------------
+
+JJ/01 installed exipick 20100104.1, adding $max_received_linelength,
+ $data_path, and $header_path variables; fixed documentation bugs and
+ typos
+
+JJ/02 installed exipick 20100222.0, added --input-dir and --finput to allow
+ exipick to access non-standard spools, including the "frozen" queue
+ (Finput)
+
+NM/01 Bugzilla 965: Support mysql stored procedures.
+ Patch from Alain Williams
+
+NM/02 Bugzilla 961: Spacing fix (syntax error) on Makefile directives for NetBSD
+
+NM/03 Bugzilla 955: Documentation fix for max_rcpts.
+ Patch from Andreas Metzler
+
+NM/04 Bugzilla 954: Fix for unknown responses from Dovecot authenticator.
+ Patch from Kirill Miazine
+
+NM/05 Bugzilla 671: Added umask to procmail example.
+
+JJ/03 installed exipick 20100323.0, fixing doc bug
+
+NM/06 Bugzilla 988: CVE-2010-2023 - prevent hardlink attack on sticky mail
+ directory. Notification and patch from Dan Rosenberg.
+
+TK/01 PDKIM: Upgrade PolarSSL files to upstream version 0.12.1.
+
+TK/02 Improve log output when DKIM signing operation fails.
+
+MH/01 Treat the transport option dkim_domain as a colon separated
+ list, not as a single string, and sign the message with each element,
+ omitting multiple occurences of the same signer.
+
+NM/07 Null terminate DKIM strings, Null initialise DKIM variable
+ Bugzilla 985, 986. Patch by Simon Arlott
+
+NM/08 Bugzilla 967. dnsdb DNS TXT record bug fix (DKIM-related)
+ Patch by Simon Arlott
+
+PP/01 Bugzilla 989: CVE-2010-2024 - work round race condition on
+ MBX locking. Notification from Dan Rosenberg.
+
+
+Exim version 4.71
+-----------------
+
+TK/01 Bugzilla 912: Fix DKIM segfault on empty headers/body.
+
+NM/01 Bugzilla 913: Documentation fix for gnutls_* options.
+
+NM/02 Bugzilla 722: Documentation for randint. Better randomness defaults.
+
+NM/03 Bugzilla 847: Enable DNSDB lookup by default.
+
+NM/04 Bugzilla 915: Flag broken perl installation during build.
+
+
+Exim version 4.70
+-----------------
+
+TK/01 Added patch by Johannes Berg that expands the main option
+ "spamd_address" if it starts with a dollar sign.
+
+TK/02 Write list of recipients to X-Envelope-Sender header when building
+ the mbox-format spool file for content scanning (suggested by Jakob
+ Hirsch).
+
+TK/03 Added patch by Wolfgang Breyha that adds experimental DCC
+ (http://www.dcc-servers.net/) support via dccifd. Activated by
+ setting EXPERIMENTAL_DCC=yes in Local/Makefile.
+
+TK/04 Bugzilla 673: Add f-protd malware scanner support. Patch submitted
+ by Mark Daniel Reidel <mr@df.eu>.
+
+NM/01 Bugzilla 657: Embedded PCRE removed from the exim source tree.
+ When building exim an external PCRE library is now needed -
+ PCRE is a system library on the majority of modern systems.
+ See entry on PCRE_LIBS in EDITME file.
+
+NM/02 Bugzilla 646: Removed unwanted C/R in Dovecot authenticator
+ conversation. Added nologin parameter to request.
+ Patch contributed by Kirill Miazine.
+
+TF/01 Do not log submission mode rewrites if they do not change the address.
+
+TF/02 Bugzilla 662: Fix stack corruption before exec() in daemon.c.
+
+NM/03 Bugzilla 602: exicyclog now handles panic log, and creates empty
+ log files in place. Contributed by Roberto Lima.
+
+NM/04 Bugzilla 667: Close socket used by dovecot authenticator.
+
+TF/03 Bugzilla 615: When checking the local_parts router precondition
+ after a local_part_suffix or local_part_prefix option, Exim now
+ does not use the address's named list lookup cache, since this
+ contains cached lookups for the whole local part.
+
+NM/05 Bugzilla 521: Integrated SPF Best Guess support contributed by
+ Robert Millan. Documentation is in experimental-spec.txt.
+
+TF/04 Bugzilla 668: Fix parallel build (make -j).
+
+NM/05.2 Bugzilla 437: Prevent Maildir aux files being created with mode 000.
+
+NM/05.3 Bugzilla 598: Improvement to Dovecot authenticator handling.
+ Patch provided by Jan Srzednicki.
+
+TF/05 Leading white space used to be stripped from $spam_report which
+ wrecked the formatting. Now it is preserved.
+
+TF/06 Save $spam_score, $spam_bar, and $spam_report in spool files, so
+ that they are available at delivery time.
+
+TF/07 Fix the way ${extract is skipped in the untaken branch of a conditional.
+
+TF/08 TLS error reporting now respects the incoming_interface and
+ incoming_port log selectors.
+
+TF/09 Produce a more useful error message if an SMTP transport's hosts
+ setting expands to an empty string.
+
+NM/06 Bugzilla 744: EXPN did not work under TLS.
+ Patch provided by Phil Pennock.
+
+NM/07 Bugzilla 769: Extraneous comma in usage fprintf
+ Patch provided by Richard Godbee.
+
+NM/08 Fixed erroneous documentation references to smtp_notquit_acl to be
+ acl_smtp_notquit, added index entry.
+
+NM/09 Bugzilla 787: Potential buffer overflow in string_format.
+ Patch provided by Eugene Bujak.
+
+NM/10 Bugzilla 770: Problem on some platforms modifying the len parameter to
+ accept(). Patch provided by Maxim Dounin.
+
+NM/11 Bugzilla 749: Preserve old behaviour of blanks comparing equal to zero.
+ Patch provided by Phil Pennock.
+
+NM/12 Bugzilla 497: Correct behaviour of exiwhat when no config exists.
+
+NM/13 Bugzilla 590: Correct handling of Resent-Date headers.
+ Patch provided by Brad "anomie" Jorsch.
+
+NM/14 Bugzilla 622: Added timeout setting to transport filter.
+ Patch provided by Dean Brooks.
+
+TK/05 Add native DKIM support (does not depend on external libraries).
+
+NM/15 Bugzilla 854: Removed code that symlinks to pcre as its no longer useful.
+ Patch provided by Graeme Fowler.
+
+NM/16 Bugzilla 851: Documentation example syntax fix.
+
+NM/17 Changed NOTICE file to remove references to embedded PCRE.
+
+NM/18 Bugzilla 894: Fix issue with very long lines including comments in
+ lsearch.
+
+NM/19 Bugzilla 745: TLS version reporting.
+ Patch provided by Phil Pennock.
+
+NM/20 Bugzilla 167: bool: condition support.
+ Patch provided by Phil Pennock.
+
+NM/21 Bugzilla 665: gnutls_compat_mode to allow compatibility with broken
+ clients. Patch provided by Phil Pennock.
+
+NM/22 Bugzilla 607: prepend (not append) Resent-Message-ID and Resent-Date.
+ Patch provided by Brad "anomie" Jorsch.
+
+NM/23 Bugzilla 687: Fix misparses in eximstats.
+ Patch provided by Heiko Schlittermann.
+
+NM/24 Bugzilla 688: Fix exiwhat to handle log_selector = +pid.
+ Patch provided by Heiko Schlittermann.
+
+NM/25 Bugzilla 727: Use transport mode as default mode for maildirsize file.
+ plus update to original patch.
+
+NM/26 Bugzilla 799: Documentation correction for ratelimit.
+
+NM/27 Bugzilla 802: Improvements to local interface IP addr detection.
+ Patch provided by David Brownlee.
+
+NM/28 Bugzilla 807: Improvements to LMTP delivery logging.
+
+NM/29 Bugzilla 862, 866, 875: Documentation bugfixes.
+
+NM/30 Bugzilla 888: TLS documentation bugfixes.
+
+NM/31 Bugzilla 896: Dovecot buffer overrun fix.
+
+NM/32 Bugzilla 889: Change all instances of "expr" in shell scripts to "expr --"
+ Unlike the original bugzilla I have changed all shell scripts in src tree.
+
+NM/33 Bugzilla 898: Transport filter timeout fix.
+ Patch by Todd Rinaldo.
+
+NM/34 Bugzilla 901: Fix sign/unsigned and UTF mistmatches.
+ Patch by Serge Demonchaux.
+
+NM/35 Bugzilla 39: Base64 decode bug fixes.
+ Patch by Jakob Hirsch.
+
+NM/36 Bugzilla 909: Correct connect() call in dcc code.
+
+NM/37 Bugzilla 910: Correct issue with relaxed/simple handling.
+
+NM/38 Bugzilla 908: Removed NetBSD3 support as no longer needed.
+
+NM/39 Bugzilla 911: Fixed MakeLinks build script.
+
+
+Exim version 4.69
+-----------------
+
+TK/01 Add preliminary DKIM support. Currently requires a forked version of
+ ALT-N's libdkim that I have put here:
+ http://duncanthrax.net/exim-experimental/
+
+ Note to Michael Haardt: I had to rename some vars in sieve.c. They
+ were called 'true' and it seems that C99 defines that as a reserved
+ keyword to be used with 'bool' variable types. That means you could
+ not include C99-style headers which use bools without triggering
+ build errors in sieve.c.
+
+NM/01 Bugzilla 592: --help option is handled incorrectly if exim is invoked
+ as mailq or other aliases. Changed the --help handling significantly
+ to do whats expected. exim_usage() emits usage/help information.
+
+SC/01 Added the -bylocaldomain option to eximstats.
+
+NM/02 Bugzilla 619: Defended against bad data coming back from gethostbyaddr.
+
+NM/03 Bugzilla 613: Documentation fix for acl_not_smtp.
+
+NM/04 Bugzilla 628: PCRE update to 7.4 (work done by John Hall).
+
+
+Exim version 4.68
+-----------------
+
+PH/01 Another patch from the Sieve maintainer.
+
+PH/02 When an IPv6 address is converted to a string for single-key lookup
+ in an address list (e.g. for an item such as "net24-dbm;/net/works"),
+ dots are used instead of colons so that keys in lsearch files need not
+ contain colons. This was done some time before quoting was made available
+ in lsearch files. However, iplsearch files do require colons in IPv6 keys
+ (notated using the quote facility) so as to distinguish them from IPv4
+ keys. This meant that lookups for IP addresses in host lists did not work
+ for iplsearch lookups.
+
+ This has been fixed by arranging for IPv6 addresses to be expressed with
+ colons if the lookup type is iplsearch. This is not incompatible, because
+ previously such lookups could never work.
+
+ The situation is now rather anomolous, since one *can* have colons in
+ ordinary lsearch keys. However, making the change in all cases is
+ incompatible and would probably break a number of configurations.
+
+TK/01 Change PRVS address formatting scheme to reflect latests BATV draft
+ version.
+
+MH/01 The "spam" ACL condition code contained a sscanf() call with a %s
+ conversion specification without a maximum field width, thereby enabling
+ a rogue spamd server to cause a buffer overflow. While nobody in their
+ right mind would setup Exim to query an untrusted spamd server, an
+ attacker that gains access to a server running spamd could potentially
+ exploit this vulnerability to run arbitrary code as the Exim user.
+
+TK/02 Bugzilla 502: Apply patch to make the SPF-Received: header use
+ $primary_hostname instead of what libspf2 thinks the hosts name is.
+
+MH/02 The dsearch lookup now uses lstat(2) instead of stat(2) to look for
+ a directory entry by the name of the lookup key. Previously, if a
+ symlink pointed to a non-existing file or a file in a directory that
+ Exim lacked permissions to read, a lookup for a key matching that
+ symlink would fail. Now it is enough that a matching directory entry
+ exists, symlink or not. (Bugzilla 503.)
+
+PH/03 The body_linecount and body_zerocount variables are now exported in the
+ local_scan API.
+
+PH/04 Added the $dnslist_matched variable.
+
+PH/05 Unset $tls_cipher and $tls_peerdn before making a connection as a client.
+ This means they are set thereafter only if the connection becomes
+ encrypted.
+
+PH/06 Added the client_condition to authenticators so that some can be skipped
+ by clients under certain conditions.
+
+PH/07 The error message for a badly-placed control=no_multiline_responses left
+ "_responses" off the end of the name.
+
+PH/08 Added -Mvc to output a copy of a message in RFC 2822 format.
+
+PH/09 Tidied the code for creating ratelimiting keys, creating them explicitly
+ (without spaces) instead of just copying the configuration text.
+
+PH/10 Added the /noupdate option to the ratelimit ACL condition.
+
+PH/11 Added $max_received_linelength.
+
+PH/12 Added +ignore_defer and +include_defer to host lists.
+
+PH/13 Installed PCRE version 7.2. This needed some changes because of the new
+ way in which PCRE > 7.0 is built.
+
+PH/14 Implemented queue_only_load_latch.
+
+PH/15 Removed an incorrect (int) cast when reading the value of SIZE in a
+ MAIL command. The effect was to mangle the value on 64-bit systems.
+
+PH/16 Another patch from the Sieve maintainer.
+
+PH/17 Added the NOTQUIT ACL, based on a patch from Ted Cooper.
+
+PH/18 If a system quota error occurred while trying to create the file for
+ a maildir delivery, the message "Mailbox is full" was not appended to the
+ bounce if the delivery eventually timed out. Change 4.67/27 below applied
+ only to a quota excession during the actual writing of the file.
+
+PH/19 It seems that peer DN values may contain newlines (and other non-printing
+ characters?) which causes problems in log lines. The DN values are now
+ passed through string_printing() before being added to log lines.
+
+PH/20 Added the "servers=" facility to MySQL and PostgreSQL lookups. (Oracle
+ and InterBase are left for another time.)
+
+PH/21 Added message_body_newlines option.
+
+PH/22 Guard against possible overflow in moan_check_errorcopy().
+
+PH/23 POSIX allows open() to be a macro; guard against that.
+
+PH/24 If the recipient of an error message contained an @ in the local part
+ (suitably quoted, of course), incorrect values were put in $domain and
+ $local_part during the evaluation of errors_copy.
+
+
Exim version 4.67
-----------------
PH/42 Another patch from the Sieve maintainer.
+SC/02 Eximstats - Differentiate between permanent and temporary rejects.
+ Eximstats - Fixed some broken HTML links and added missing column headers
+ (Jez Hancock).
+ Eximstats - Fixed Grand Total Summary Domains, Edomains, and Email
+ columns for Rejects, Temp Rejects, Ham, and Spam rows.
+
+SC/03 Eximstats - V1.58 Fix to get <> and blackhole to show in edomain tables.
+
+PH/43 Yet another patch from the Sieve maintainer.
+
+PH/44 I found a way to check for a TCP/IP connection going away before sending
+ the response to the final '.' that terminates a message, but only in the
+ case where the client has not sent further data following the '.'
+ (unfortunately, this is allowed). However, in many cases there won't be
+ any further data because there won't be any more messages to send. A call
+ to select() can be used: if it shows that the input is "ready", there is
+ either input waiting, or the socket has been closed. An attempt to read
+ the next input character can distinguish the two cases. Previously, Exim
+ would have sent an OK response which the client would never have see.
+ This could lead to message repetition. This fix should cure that, at
+ least in a lot of common cases.
+
+PH/45 Do not advertise STARTTLS in response to HELP unless it would be
+ advertised in response to EHLO.
+
Exim version 4.66
-----------------