Re: On the harm of adding new methods

From: Koen Holtman (koen@win.tue.nl)
Date: Thu, Jun 11 1998


From: koen@win.tue.nl (Koen Holtman)
Message-Id: <199806111819.UAA22553@wsooti08.win.tue.nl>
To: fielding@kiwi.ics.uci.edu (Roy T. Fielding)
Date: Thu, 11 Jun 1998 20:19:11 +0200 (MET DST)
Cc: masinter@parc.xerox.com, ipp@pwg.org, ietf-http-ext@w3.org
Subject: Re: On the harm of adding new methods

Roy T. Fielding:
>
  [Larry Masinter:]
>>Forwarders MUST actually understand methods, because -- unfortunately --
>>the meaning of HTTP headers and responses differ based on the method
>>of the request (e.g., Content-Length for HEAD vs GET). Many forwarding
>>systems will not accept new methods gracefully. 
>
>Actually, that is only true for HEAD and GET -- all header fields have
>the same meaning for all other methods. 
 [...]
> I can't think of any other
>exceptions at the moment -- if any have been added in the past year
>or so, they need to be removed.

I just checked the latest revision of the spec and no other exceptions
have been added.  

Also, reviewing the material in sections 4.3 and 4.4, I conclude that
it is possible to make an HTTP/1.1 forwarder which will correctly
forward any 1.1 message even if it has an unknown new method.  This is
of course as it should be: the spec would be broken otherwise.

Koen.