Re: Working Group Last Call: draft-ietf-httpbis-content-disp-02

* Adam Barth wrote:
>This document appears to be insufficiently precise for user agents to
>implement Content-Disposition.  In particular, it does not
>disambiguate what filename a user agent should use if multiple
>filename attributes are present.  The grammar will fail to parse a
>large number of Content-Disposition headers user agents receive on the
>public Internet, etc.  The document says:

The parameters are advisory only; the draft defines that `filename*`
gives better advice than `filename`; there is little need to specify
something beyond that. As for content that falls outside the profile
here, browsers don't really agree on much. For instance,

  Content-Disposition: inline; attachment; filename=example.txt

that's "inline" in Opera and Firefox, but "attachment" in IE6. Something
that actually occurs practise is unquoted spaces,

  Content-Disposition: attachment; filename=ex ample.txt

That's "ex" in Firefox, but "ex ample.txt" in Opera and IE6. Malformed

  Content-Disposition: attachment;filename="example.txt".txt

is rejected as malformed by IE6 which then makes up its own name, but
it ends up as "example.txt" in Firefox and Opera. If we take the in-
tersection of what works in all major browsers and what actually occurs
in practise where it is more than a slight inconvenience for the user
if the header is ignored alltogether, we won't end up with something
that's noticably different than what's in the draft.

>We should either add enough detail to the document to allow for user
>agent implementations or clarify that this document is intended to
>apply only to servers.

That would be missing the point. The point of a profile specification is
that if a sender sends out something that conforms to the profile, then
recepients will process it in a manner conforming to the specification.
Björn Höhrmann · ·
Am Badedeich 7 · Telefon: +49(0)160/4415681 ·
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Received on Saturday, 2 October 2010 19:46:38 UTC