Milter-greylist

According to Matt Kettler:
> > 
> > http://ftp.espci.fr/pub/milter-greylist/milter-greylist-3.0rc5.tgz
> > MD5 (milter-greylist-3.0rc5.tgz) = 82326be5d21ca8ef7bb4e3cdbcbd23c6
> 
> For what it's worth, I can't build 3.0rc5 without a little hand-hacking.

I can't either using Linux and --enable-dnsrbl 

gcc -g -O2 -Wall -D_XOPEN_SOURCE=500 -DUSE_DNSRBL -D_BSD_SOURCE   -c -o dnsrbl.o dnsrbl.c
dnsrbl.c: In function 'dnsrbl_check_source':
dnsrbl.c:163: warning: pointer targets in passing argument 5 of '__res_nquery' differ in signedness
dnsrbl.c:167: warning: pointer targets in passing argument 1 of '__ns_initparse' differ in signedness

...

gcc -o milter-greylist milter-greylist.o pending.o sync.o dnsrbl.o list.o macro.o conf_yacc.o dump_yacc.o conf.o autowhite.o dump.o spf.o acl.o  -lresolv -lnsl -lpthread -lmilter
dnsrbl.o: In function `dnsrbl_check_source':/src/milter-greylist-3.0rc5/dnsrbl.c:167: undefined reference to `__ns_initparse'
:/src/milter-greylist-3.0rc5/dnsrbl.c:174: undefined reference to `__ns_parserr'
collect2: ld returned 1 exit status
make: *** [milter-greylist] Error 1


It's okay if I don't specify --enable-dnsrbl.
With --enable-dnsrbl, it must be linked with /usr/lib/libresolv.a
instead of -lresolv. Maybe -lbind could do it (I don't have it on that box).

BTW, my patch for configure.ac in 2.1.* has been changed at some point from:

       [if test x$enableval = xyes; then
               if test $rdns = yes; then
                       CFLAGS=$CFLAGS" -DUSE_DNSRBL"
               else
                       echo "--enable-dnsrbl used but DNS resolver is not thread safe";
                       echo "Try installing BIND9 and using --with-libbind, or if you";
                       echo "know what you are doing, use --with-thread-safe-resolver";
                       exit 1;
               fi
        fi


to

       [if test x$enableval = xyes -a $rdns = yes; then
               CFLAGS=$CFLAGS" -DUSE_DNSRBL"
        else
               echo "--enable-dnsrbl used but DNS resolver is not thread safe";
               echo "Try installing BIND9 and using --with-libbind, or if you";
               echo "know what you are doing, use --with-thread-safe-resolver";
               exit 1;
        fi

..but this is not equivalent and it's even wrong as --disable-dnsrbl will
produce the echo. Please revert that change.

/Fabien