Bug#468318: string expansion bug

[Jens Zahner]

Package: exim4-daemon-heavy
Version: 4.63-17

The following code produces an error when using in exim configuration file and by testing 
via "exim4 -be".

${map {sbl-xbl.spamhaus.org#10 : list.dsbl.org#10} {${lookup \
dnsdb{defer_never,a=1.1.1.1.${extract{1}{#}{$item}}} {${extract{2}{#}{$item}}} {0}} } }

Error message:
Failed: "${map" is not a known operator (or a } is missing in a variable reference)

The expected result should be: "0 :0"

-- Package-specific info:
Exim version 4.63 #1 built 20-Jan-2007 10:42:32
Copyright (c) University of Cambridge 2006
Berkeley DB: Sleepycat Software: Berkeley DB 4.3.29: (September  6, 2005)
Support for: crypteq iconv() IPv6 PAM Perl GnuTLS move_frozen_messages Content_Scanning 
Old_Demime
Lookups: lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmnz dnsdb dsearch ldap 
ldapdn ldapm mysql nis nis0 passwd pgsql sqlite
Authenticators: cram_md5 cyrus_sasl 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: 4.0
Architecture: i386 (i686)