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Re: httpbis-p6-cache-06 and no-store response directive

From: Jamie Lokier <jamie@shareable.org>
Date: Wed, 24 Jun 2009 22:03:48 +0100
To: "Yngve N. Pettersen (Developer Opera Software ASA)" <yngve@opera.com>
Cc: "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Message-ID: <20090624210348.GZ14121@shareable.org>
Yngve N. Pettersen (Developer Opera Software ASA) wrote:
> Additionally, the default in PHP (at least my copy of v5.0.4) seems to be  
> "Cache-Control: no-store, no-cache, must-revalidate, post-check=0,  
> pre-check=0", and I seem to recall that the MoinMoin wiki had that, too,  
> at least last year (but in that case I may be misremembering).
> Given the extensive use of no-store in situations where it does not seem  
> necessary, I have started wondering if Opera need to start ignoring the  
> no-store header in non-HTTPS responses, just like we currently only accept  
> must-revalidate (interpreted as re-validate on history navigation) only  
> for HTTPS responses. No decision has been reached yet.

Oh.  My.  Goodness.

You ignore must-revalidate?

Thanks for letting me know that Opera is broken.

      "Recipients MUST NOT take any automated action that
      violates this directive, and MUST NOT automatically provide an
      unvalidated copy of the entity if revalidation fails."

Do you have a suggested workaround for this client bug?  The only one
which comes to mind is redirecting to an HTTPS-equivalent page when
the User-Agent indicates Opera.  Something cheaper would be nice.

If I've set must-revalidate, it's because I want my Etags revalidated,
thank you.  As in, when the user visits the page, they must not see an
out of date page.  It causes confusion if they do.  Web applications,
you know the sort of thing.

Your interpretation that the directive wasn't really intended is just
another step in a silly arms-race, where we have to add yet more
workaround on the server side to compensate for clients who don't
follow simple specifications.

-- Jamie
Received on Wednesday, 24 June 2009 21:04:26 UTC

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