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

Julian Reschke <julian.reschke@gmx.de> Tue, 12 May 2020 17:41 UTC

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To: Willy Tarreau <w@1wt.eu>
Cc: HTTP Working Group <ietf-http-wg@w3.org>
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From: Julian Reschke <julian.reschke@gmx.de>
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Date: Tue, 12 May 2020 19:38:13 +0200
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Subject: Re: draft-ietf-httpbis-header-structure: handling multiple field values
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On 12.05.2020 19:23, Willy Tarreau wrote:
> 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.
> ...

Yes, understood. (and that's actually mentioned in the spec)

Best regards, Julian