Make sure there always is a Host: header in fetch requests.

We fill it in with backend.hostname, but this may not be optimal
(direct IP# etc etc) so VCL should be able to override it.



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@563 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache_fetch.c

@@ -258,6 +258,7 @@ FetchHeaders(struct sess *sp)
 	int i;
 	struct vbe_conn *vc;
 	struct worker *w;
+	char *b;
 
 	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
 	CHECK_OBJ_NOTNULL(sp->wrk, WORKER_MAGIC);
@@ -276,6 +277,10 @@ FetchHeaders(struct sess *sp)
 	http_GetReq(vc->fd, vc->http, sp->http);
 	http_FilterHeader(vc->fd, vc->http, sp->http, HTTPH_R_FETCH);
 	http_PrintfHeader(vc->fd, vc->http, "X-Varnish: %u", sp->xid);
+	if (!http_GetHdr(vc->http, H_Host, &b)) {
+		http_PrintfHeader(vc->fd, vc->http, "Host: %s",
+		    sp->backend->hostname);
+	}
 
 	sp->t_req = time(NULL);
 	WRK_Reset(w, &vc->fd);