tcp: set hints for address resolution

getaddrinfo really likes to get hints on how to resolve. This should fix
the problem where 'localhost' can not be used as a hostname.

This should work with AF_UNSPEC but may need to be reverted to AF_INET.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>

src/tcp.c

@@ -76,12 +76,14 @@ tcp_connect(const char *hostname, int port, const char *bindaddr,
             char *errbuf, size_t errbufsize, int timeout)
 {
   int fd, r, res, err;
-  struct addrinfo *ai;
+  struct addrinfo *ai, hints;
   char portstr[6];
   socklen_t errlen = sizeof(err);
 
   snprintf(portstr, 6, "%u", port);
-  res = getaddrinfo(hostname, portstr, NULL, &ai);
+  memset(&hints, 0, sizeof(struct addrinfo));
+  hints.ai_family = AF_UNSPEC;
+  res = getaddrinfo(hostname, portstr, &hints, &ai);
 
   if (res != 0) {
     snprintf(errbuf, errbufsize, "%s", gai_strerror(res));