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Re: #306: does etag value really use quoted-string

From: Yves Lafon <ylafon@w3.org>
Date: Mon, 5 Sep 2011 09:17:36 -0400 (EDT)
To: Julian Reschke <julian.reschke@gmx.de>
cc: Mark Nottingham <mnot@mnot.net>, HTTP Working Group <ietf-http-wg@w3.org>
Message-ID: <alpine.DEB.1.10.1109050915390.3699@wnl.j3.bet>
On Thu, 1 Sep 2011, Julian Reschke wrote:

>
> 2.3.  ETag
>
>   The ETag header field provides the current entity-tag for the
>   selected representation.  An entity-tag is an opaque validator for
>   differentiating between multiple representations of the same
>   resource, regardless of whether those multiple representations are
>   due to resource state changes over time, content negotiation
>   resulting in multiple representations being valid at the same time,
>   or both.  An entity-tag consists of an opaque quoted string, possibly
>   prefixed by a weakness indicator.
>
>     ETag       = entity-tag
>
>     entity-tag = [ weak ] opaque-tag
>     weak       = %x57.2F ; "W/", case-sensitive
>     opaque-tag = DQUOTE *etagc DQUOTE
>     etagc      = %x21 / %x23-7E / obs-text
>                ; VCHAR except double quotes, plus obs-text

How about removing %x5C as well '\' and note that implementations were not 
handling \ as a quoted-string as it was defined before, leading to 
non-interoperable parsing of such ETags.

  >
>      Note: Previously, opaque-tag was defined to be a quoted-string
>      ([RFC2616], Section 3.11), thus some recipients might perform
>      backslash unescaping.  Servers therefore ought to avoid backslash
>      characters in entity tags.
>
>      ...
>
> Best regards, Julian
>
>

-- 
Baroula que barouleras, au tiéu toujou t'entourneras.

         ~~Yves
Received on Monday, 5 September 2011 13:17:38 GMT

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