Re: Last Call: <draft-ietf-httpbis-header-structure-18.txt> (Structured Field Values for HTTP) to Proposed Standard

Willy Tarreau <w@1wt.eu> Sat, 16 May 2020 04:35 UTC

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Date: Sat, 16 May 2020 06:31:51 +0200
From: Willy Tarreau <w@1wt.eu>
To: Julian Reschke <julian.reschke@gmx.de>
Cc: Poul-Henning Kamp <phk@phk.freebsd.dk>, mnot@mnot.net, phk@varnish-cache.org, last-call@ietf.org, httpbis-chairs@ietf.org, ietf-http-wg@w3.org, barryleiba@gmail.com, draft-ietf-httpbis-header-structure@ietf.org
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Subject: Re: Last Call: <draft-ietf-httpbis-header-structure-18.txt> (Structured Field Values for HTTP) to Proposed Standard
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On Sat, May 16, 2020 at 05:39:32AM +0200, Julian Reschke wrote:
> I have no idea what the exact proposal would be. Fail when multiple
> instances are there?

That would be really annoying, because the main reason multiple headers
happen is that most of these are inconditionally added by components
which do not search for them. Look at the famous x-forwarded-for as an
example!

I'd say that multiple headers are the most natural way to produce an
ordered list, and one which will continue to exist.

Willy