Subject: ISSUE-280: whitespace in parameter syntax?

From: Julian Reschke <[email-masked]>
Date: Sun, 06 Mar 2011 12:19:51 +0100

Hi,	

see <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/280>...:

Section 2.3 of draft-ietf-httpbis-p3-payload:

   parameter      = attribute "=" value
   attribute      = token
   value          = word

I believe we need OWS around "=".

(The grammar didn't change from 2616, but we 2616 had implied LWS...).

Best regards, Julian

---

From: Julian Reschke <[email-masked]>
Date: Sun, 06 Mar 2011 18:53:06 +0100

> (The grammar didn't change from 2616, but we 2616 had implied LWS...).

Philip Jägenstedt points out on the HTML WG mailing list that RFC 2616 
said in the prose:

"Linear white space (LWS) MUST NOT be used between the type and subtype, 
nor between an attribute and its value."

So what HTTPbis says in P3 is consistent with that.

That being said, RFC 5987, RFC 5988 and the Content Disposition draft 
disagree with this, and *do* allow linear white space (RFC 5987 puts it 
in explicitly, RFC 5988 inherits 2616 ABNF rules, and so does C-D).

I see two ways out:

- recognize that 5987 and 5988 are wrong, raise errata, and fix C-D 
before it goes to the IESG

- recognize that 5987 and 5988 reflect common usage, and potentially fix 
it in HTTPbis

Feedback appreciated,

Julian

---

From: Mark Nottingham <[email-masked]>
Date: Mon, 7 Mar 2011 17:47:13 +1300

I recall that we purposefully omitted OWS around the '=' because of this.

On 07/03/2011, at 6:53 AM, Julian Reschke wrote:

> Philip Jägenstedt points out on the HTML WG mailing list that RFC 2616 said in the prose:
> 
> "Linear white space (LWS) MUST NOT be used between the type and subtype, nor between an attribute and its value."
> 
> That being said, RFC 5987, RFC 5988 and the Content Disposition draft disagree with this, and *do* allow linear white space (RFC 5987 puts it in explicitly, RFC 5988 inherits 2616 ABNF rules, and so does C-D).
> 
> I see two ways out:
> 
> - recognize that 5987 and 5988 are wrong, raise errata, and fix C-D before it goes to the IESG
> 
> - recognize that 5987 and 5988 reflect common usage, and potentially fix it in HTTPbis
> 
> Feedback appreciated,
> 
> Julian
> 

--
Mark Nottingham   http://www.mnot.net/

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From: "Roy T. Fielding" <[email-masked]>
Date: Mon, 7 Mar 2011 14:09:59 -0800

> - recognize that 5987 and 5988 reflect common usage, and potentially fix it in HTTPbis

I do not know of any such usage, let alone common.

....Roy

---

From: Julian Reschke <[email-masked]>
Date: Tue, 08 Mar 2011 08:36:23 +0100

On 07.03.2011 23:09, Roy T. Fielding wrote:
> ...

This may be an artefact from RFC2068/2616 not really using "parameter" 
as common protocol element. If you look at 
<http://tools.ietf.org/html/rfc2068#section-19.6.2.4> (Link) and 
<http://greenbytes.de/tech/webdav/rfc2616.html#rfc.section.19.5.1> 
(Content-Disposition), you will notice they do not use the generic 
parameter ABNF; and thus are not affected by the prose over there.

Furthermore, <http://greenbytes.de/tech/tc2231/> shows that browsers 
universally accept LSWP around "=" for Content-Disposition, so I 
wouldn't be surprised if senders rely on it.

We probably should have similar tests for Content-Type.

Best regards, Julian