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

This is mentioned in
https://httpwg.org/http-extensions/draft-ietf-httpbis-header-structure.html#rfc.section.4.2
--
"parsers MUST combine all lines in the same section (header or trailer)
that case-insensitively match the field name into one comma-separated
field-value", (with the warning given that strings split across multiple
field values will have "unpredictable results") -- So I don't think you're
allowed to parse them separately. If both exist in the same message, they
must be combined before parsing.

On Tue, May 12, 2020 at 1:27 PM Willy Tarreau <w@1wt.eu> 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.
>
> Regards,
> Willy
>
>