Re: p1: BWS

Mark Nottingham <mnot@mnot.net> Thu, 18 April 2013 22:58 UTC

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From: Mark Nottingham <mnot@mnot.net>
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Date: Fri, 19 Apr 2013 08:27:21 +1000
Cc: Willy Tarreau <w@1wt.eu>, Amos Jeffries <squid3@treenet.co.nz>, HTTP Working Group <ietf-http-wg@w3.org>
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To: Roberto Peon <grmocg@gmail.com>
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Subject: Re: p1: BWS
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We can either:

- make it a MUST
- document what the exceptional circumstances are that cause the SHOULD (but I don't think it's that kind of SHOULD)
- downgrade it to an "ought to"

I do note that we say "generate" there (which I missed before, sorry); in our terminology, that means you DON'T need to fix it up when forwarding it; it's only when you're actually creating the element that this applies.

So, I'd suggest we make it a MUST, and change the language slightly to clarify:

"...but it MUST NOT be generated in messages..."

Also, in p2, I'd note that we do NOT allow BWS inside of media type parameters:
  https://svn.tools.ietf.org/svn/wg/httpbis/draft-ietf-httpbis/latest/p2-semantics.html#media.type

AIUI (thanks, Julian), this is because many implementations don't accept whitespace there at all. It might be worth noting in the text that this parameter construct is different in that aspect.

Cheers,


On 19/04/2013, at 8:17 AM, Roberto Peon <grmocg@gmail.com> wrote:

> As an implementer having written code to handle this, I don't see a lot of value in making it a MUST, when I'll need to have my servers handle it anyway, in the off-chance that the load-balancer is changed or is not there.
> It is really a nice-to-have kind of thing.
> -=R
> 
> 
> On Thu, Apr 18, 2013 at 5:25 AM, Mark Nottingham <mnot@mnot.net> wrote:
> 
> On 18/04/2013, at 4:02 PM, Willy Tarreau <w@1wt.eu> wrote:
> >
> > Agreed, but on the other hand, requiring that some intermediaries that do
> > not even use these fields to fix them can increase the risk of breaking
> > something between the client and the server. And since many of them will
> > not do it anyway, we'll end up with another MUST that is not respected,
> > so probably a SHOULD would be more appropriate ?
> 
> 
> A SHOULD is not a MUST that we sort-of mean. At least, that's not what we say, even if it is how we tend to use it sometimes (more feedback forthcoming).
> 
> Cheers,
> 
> --
> Mark Nottingham   http://www.mnot.net/
> 
> 
> 
> 
> 

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