Patch to spamc for debugging w.r.t. spamd

[Andrew Donkin]

While working on scaling problems I needed to match spamc's debugging
output with spamd's.  That is laborious when you've got multiple MX
hosts connecting to multiple spamd hosts.

This patch to spamc.c reveals the port number from which spamc
connects to spamd.  Spamd already logs the same, so matching them up
is a doddle.

The patch isn't portable, and you'll need a fair bit of fuzz to get it
to apply.  But I expect you will already have worked on spamc.c a fair
bit to get it to compile with DO_CONNECT_DEBUG_SYSLOGS, so muscling
this patch in won't be a challenge to you.  I felt it should be in the
archive.

@@ -438,8 +440,18 @@
        }
        else {
 #ifdef DO_CONNECT_DEBUG_SYSLOGS
-           libspamc_log(tp->flags, DEBUG_LEVEL,
+         struct sockaddr_in namebuf;
+         socklen_t namesize = sizeof(namebuf);
+
+         memset(&namebuf, 0, sizeof(namebuf));
+         if (getsockname(mysock, (struct sockaddr *) &namebuf, &namesize)) {
+           libspamc_log(tp->flags, LOG_DEBUG,
                   "dbg: connect(AF_INET) to spamd at %s done", ipaddr);
+         } else {
+           libspamc_log(tp->flags, LOG_DEBUG,
+                        "dbg: connect(AF_INET) to spamd at %s done, local port 
%d",
+                        ipaddr, ntohs(namebuf.sin_port));
+         }
 #endif
            *sockptr = mysock;