Bug#781085: router: headers_remove broken?

[Ralf G. R. Bergs]

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

Dear Maintainer,

I have the following router in my config which suddenly failed on an
Exim upgrade (Debian package was upgraded probably from exim4-daemon-heavy:amd64
(4.82.1-1+b1, 4.82.1-2) to exim4-daemon-heavy:amd64 (4.82.1-2, 4.83-2)
according to my investigations, but the issue can still be observed on
today's Debian Jessie's Exim exim4-daemon-heavy (4.84-8)):

virtual_domains:
  domains = ! @[] : ! @ : +local_domains
  driver = redirect
  allow_fail
  data = /home/rabe/var/mail/mydomain.de/rabe/Maildir
  headers_remove = ${if ={40}{40} {A:B:C}{}}
  local_part_suffix = +* : -*
  local_part_suffix_optional
  retry_use_local_part
  file_transport = virtual_delivery
  reply_transport = address_reply
  pipe_transport = address_pipe

The headers_remove line is a stripped down version that gives me the
same error message as the original (fully-functional) one:

R=virtual_domains defer (-1): virtual_domains router failed to expand
"${if ={40}{40} {A:B:C}{}}": missing } at end of string

I was just able to confirm that "my" bug disappears when downgrading to
Debian's Exim package exim-daemon-heavy 4.82.1-1+b1 (version string
the binary outputs is 4.82_1-5b7a7c0-XX).

Please also see the following bug report by s/o else (which I updated
with the above info):

http://bugs.exim.org/show_bug.cgi?id=1533

Kind regards,

Ralf

-- 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
Configuration file is /etc/exim4/exim4.conf

-- System Information:
Debian Release: 8.0
  APT prefers testing-updates
  APT policy: (500, 'testing-updates'), (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages exim4-daemon-heavy depends on:
ii  debconf [debconf-2.0]  1.5.55
ii  exim4-base             4.84-8
ii  libc6                  2.19-15
ii  libdb5.3               5.3.28-9
ii  libgnutls-deb0-28      3.3.8-6
ii  libldap-2.4-2          2.4.40-4
ii  libmysqlclient18       5.5.42-1
ii  libpam0g               1.1.8-3.1
ii  libpcre3               2:8.35-3.3
ii  libperl5.20            5.20.2-2
ii  libpq5                 9.4.1-1
ii  libsasl2-2             2.1.26.dfsg1-13
ii  libsqlite3-0           3.8.7.1-1

exim4-daemon-heavy recommends no packages.

exim4-daemon-heavy suggests no packages.

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