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Several Content-Encodings

From: Florent Guillaume <guillaum@clipper.ens.fr>
Date: Wed, 10 Apr 1996 16:21:18 +0200 (MET DST)
Message-Id: <199604101421.QAA07421@clipper.ens.fr>
To: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
The Apache mailing list stumbled on this problem when discussing
multiple Content-Encodings in a document.

[David]
> HTTP/1.0 does not support multiple content-encodings.
> HTTP/1.1 suggests an implementation of multiple content-encodings which
> is broken; the ordering of the encodings is not defined. I'm sure I
> mentioned this on http-wg, but I can't remeber the outcome. Roy?

That is, the ordering *is* defined if it appears in a single
Content-Encoding header, but the spec leaves some margin if
you have several ones that you want to collapse.

draft-ietf-http-v11-spec-01.txt says
  [section 10.10]
   If multiple encodings have been applied to a resource, the content
   codings must be listed in the order in which they were applied.

But, as Brian pointed out, it also says

  [section 4.2]
   The order in which header fields are received is not significant.
and
   It must be possible to combine the multiple header fields into one
   "field-name: field-value" pair, without changing the semantics of
   the message, by appending each subsequent field-value to the first,
   each separated by a comma.

Which is clearly broken, the semantics *is* changed.

Has this been resolved/discussed ?
Can Section 4.2 make an exception about ordering for the Content-Encoding
headers, or is this too ugly ?

-- Florent
Received on Friday, 12 April 1996 00:12:28 EDT

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