Make a new function called resolve_all in tcpip.cc, which is like

resolve except that it returns all resolved addresses. Use this new
function to resolve IPv4 addresses instead of gethostbyname in
TargetGroup.cc. The gethostbyname code assumed that only IPv4 addresses
would be returned. If the resolver returned IPv6 addresses, TargetGroup
would blindly copy the first four bytes of the IPv6 address into the
IPv4 struct. This was first reported by Mats Erik Andersson at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=584301; he also
suggested the fix.

tcpip.h

@@ -435,6 +435,11 @@ struct icmp
    not thread-safe and can only be used once in calls like printf() 
 */
 const char *inet_socktop(struct sockaddr_storage *ss);
+/* Tries to resolve the given name (or literal IP) into a sockaddr
+   structure. This function calls getaddrinfo and returns the same
+   addrinfo linked list that getaddrinfo produces. Returns NULL for any
+   error or failure to resolve. */
+struct addrinfo *resolve_all(char *hostname, int pf);
 /* Tries to resolve the given name (or literal IP) into a sockaddr
    structure.  The af should be PF_INET (for IPv4) or PF_INET6.  Returns 0
    if hostname cannot be resolved.  It is OK to pass in a sockaddr_in or