Re: draft-ietf-httpbis-header-structure: handling multiple field values

Willy Tarreau <w@1wt.eu> Tue, 12 May 2020 17:26 UTC

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Date: Tue, 12 May 2020 19:23:47 +0200
From: Willy Tarreau <w@1wt.eu>
To: Julian Reschke <julian.reschke@gmx.de>
Cc: HTTP Working Group <ietf-http-wg@w3.org>
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Subject: Re: draft-ietf-httpbis-header-structure: handling multiple field values
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Hi Julian,

On Tue, May 12, 2020 at 06:53:40PM +0200, Julian Reschke wrote:
> Hi there,
> 
> while working on an implementation I encountered the following question.
> 
> Consider something defined as "sh-list". If a value is received spread
> over multiple field instances, recipients *can* recombine the value
> before processing. So for
> 
>   Foo: "1
>   Foo: 2"
> 
> ...the parser would see the string "1,2" (or maybe "1, 2").
> 
> What's not totally clear to me is whether recipients are *allowed* to
> process the field values separately, in which case parsing would fail.

Note that they might not be aware that these were two values
because the folding might have been performed by an upstream
gateway.

Regards,
Willy