Subject: Re: Host header issue

From: Geoff Macartney <[email-masked]>
Date: Thu, 30 Sep 1999 14:21:17 +0100

In the recent discussion on this topic I haven't seen a query on the
text in section 14.23 "Host"  of RFC 2616 which says :

  "If the requested URI does not include an Internet host
   name for the service being requested, then the Host header field MUST

   be given with an empty value. "

It is the "with an empty value" that confuses me - this seems to
contradict what is written in section 5.1.2:
  "The most common form of Request-URI is that used to identify a
   resource on an origin server or gateway. In this case the absolute
   path of the URI MUST be transmitted (see section 3.2.1, abs_path) as
   the Request-URI, and the network location of the URI (authority) MUST

   be transmitted in a Host header field. "
[...]
       GET /pub/WWW/TheProject.html HTTP/1.1
       Host: www.w3.org

If the text in 14.23 were followed you'd get

       GET /pub/WWW/TheProject.html HTTP/1.1
       Host:

which would surely be wrong. My understanding from the spec and this
discussion thread is that it should be possible to identify the host,
whether by a relative URI plus valid Host value or by an absolute URI
(plus redundant Host header, which I suppose you could legitimately
allow to have an empty value in this case?)

Is this one for the errata?

Geoff Macartney

---

From: "Roy T. Fielding" <[email-masked]>
Date: Thu, 30 Sep 1999 14:17:07 -0700

>   be transmitted in a Host header field. "

Some URI do not have an authority component, and therefore have no host,
but can still be requested from an HTTP proxy.  This is not a contradiction.

....Roy