Bug#793774: exim4-daemon-heavy: headers_remove items not expanding correct due limited buffer size

[Christian Leonhardt]

Package: exim4-daemon-heavy
Version: 4.84-8
Severity: normal

Dear Maintainer,

with the latest stable release of exim4 in Jessie my vexim2 installation (https://github.com/avleen/vexim2) is failing.
The error is not reproducible with 4.80-7+deb7u1 from Wheezy.
The bug  is already known at the exim list (https://bugs.exim.org/show_bug.cgi?id=1533) and probably fixed.
The problem occurs while expanding the following headers_remove item:

headers_remove = ${if or { { <{$spam_score_int}{1} } \
	         { <{$spam_score_int}{${lookup mysql{select users.sa_tag * 10 from users,domains \
	           where localpart = '${quote_mysql:$local_part}' \
	           and domain = '${quote_mysql:$domain}' \
	           and users.on_spamassassin = 1 \
	           and users.domain_id=domains.domain_id}{$value}fail}} } \
	         { eq {0}{${lookup mysql{select users.sa_tag * 10 from users,domains \
	           where localpart = '${quote_mysql:$local_part}' \
	           and domain = '${quote_mysql:$domain}' \
	           and users.on_spamassassin = 0 \
	           and users.domain_id=domains.domain_id}{$value}fail}}} \
	       } {X-Spam-Score:X-Spam-Report} }

At the moment my workaround is to use a shortened version of the above filter.

-- Package-specific info:
Exim version 4.84 #2 built 17-Feb-2015 17:45:46
Copyright (c) University of Cambridge, 1995 - 2014
(c) The Exim Maintainers and contributors in ACKNOWLEDGMENTS file, 2007 - 2014
Berkeley DB: Berkeley DB 5.3.28: (September  9, 2013)
Support for: crypteq iconv() IPv6 PAM Perl Expand_dlfunc GnuTLS move_frozen_messages Content_Scanning DKIM Old_Demime PRDR OCSP
Lookups (built-in): lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmjz dbmnz dnsdb dsearch ldap ldapdn ldapm mysql nis nis0 passwd pgsql sqlite
Authenticators: cram_md5 cyrus_sasl dovecot plaintext spa
Routers: accept dnslookup ipliteral iplookup manualroute queryprogram redirect
Transports: appendfile/maildir/mailstore/mbx autoreply lmtp pipe smtp
Fixed never_users: 0
Size of off_t: 8

-- System Information:
Debian Release: 8.1
  APT prefers stable
  APT policy: (900, 'stable'), (500, 'stable-updates')
Architecture: amd64 (x86_64)

Kernel: Linux 3.16.0-4-amd64 (SMP w/1 CPU core)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages exim4-daemon-heavy depends on:
ii  debconf [debconf-2.0]  1.5.56
ii  exim4-base             4.84-8
ii  libc6                  2.19-18
ii  libdb5.3               5.3.28-9
ii  libgnutls-deb0-28      3.3.8-6+deb8u1
ii  libldap-2.4-2          2.4.40+dfsg-1
ii  libmysqlclient18       5.5.44-0+deb8u1
ii  libpam0g               1.1.8-3.1
ii  libpcre3               2:8.35-3.3
ii  libperl5.20            5.20.2-3+deb8u1
ii  libpq5                 9.4.3-0+deb8u1
ii  libsasl2-2             2.1.26.dfsg1-13
ii  libsqlite3-0           3.8.7.1-1+deb8u1

exim4-daemon-heavy recommends no packages.

exim4-daemon-heavy suggests no packages.

-- debconf information:
  exim4-daemon-heavy/drec: