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Re: #327: Expect syntax

From: Willy Tarreau <w@1wt.eu>
Date: Sat, 17 Dec 2011 22:58:05 +0100
To: Julian Reschke <julian.reschke@gmx.de>
Cc: Alex Rousskov <rousskov@measurement-factory.com>, HTTP Working Group <ietf-http-wg@w3.org>
Message-ID: <20111217215805.GC21202@1wt.eu>
On Sat, Dec 17, 2011 at 10:12:05PM +0100, Julian Reschke wrote:
> >However
> >the semi-colon after 100-continue was not supposed to happen in 2616,
> >which is why I think other implementations might get trapped.
> That is true, but it *is* an edge case.


> The alternative is to make the grammar different from Prefer:; or to 
> change Prefer: as well.

We have enough different grammars, let's try to factor them as much as

> In practice, most parsers that understand ";" separated parameters allow 
> "empty" parameters (see, for instance, my Content-Disposition test 
> cases). We can pretend this is wrong, or we can try to bring a bit more 
> sanity to this.
> In any case, the fact that existing implementations might trip over 
> something that (for Expect!) will only happen in test cases doesn't seem 
> to be a big problem to me.

Well, it's possible that in a few years we see new implementations write
their Expect header as $expectation ";" $extension but by this time, server
implementations will have applied the rules from the new RFC and will support
the extra semi-colon. I'm not quite worried, I just wanted to outline that
*some* existing implementations are not compatible with the proposal, that's

Best Regards,
Received on Saturday, 17 December 2011 21:58:46 UTC

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