Subject: Working Group Last Call: Content-Disposition

From: Julian Reschke <[email-masked]>
Date: Sun, 17 Oct 2010 20:04:06 +0200

Hi everybody,

there are six days left for the WG LC, and I'm planning to submit a new 
draft in time before the ID submission cut-off in eight days.

I've been tracking issues at 
<http://trac.tools.ietf.org/wg/httpbis/trac/query?component=content-disp>:

There are currently four of them:

1) <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/243>: "avoid 
stating ISO-8859-1 default for header param"

This was raised by Björn (in fact before LC); I'd still like to get more 
feedback on this.

2) <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/244>: "state that 
repeating parameters are invalid"

Addressed in "latest" draft with 
<http://trac.tools.ietf.org/wg/httpbis/trac/changeset/1024>.

3) <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/245>: "warn about 
%xx in filenames being misinterpreted"

(not yet addressed)

4) <http://trac.tools.ietf.org/wg/httpbis/trac/ticket/246>: "mention 
control chars when talking about postprecessing the filename parameter"

Addressed in "latest" draft with 
<http://trac.tools.ietf.org/wg/httpbis/trac/changeset/1022>.

Best regards, Julian

---

From: Julian Reschke <[email-masked]>
Date: Thu, 21 Oct 2010 14:02:36 +0200

On 17.10.2010 20:04, Julian Reschke wrote:
> ...
> ...

It just occurred to me that there may be a workaround for this problem, 
by using the quoted-string form and inserting a quote character into the 
%xx sequence.

Not so, because of UAs not handling escapes properly. Sigh. See test case:

    <http://greenbytes.de/tech/tc2231/#attwithfnrawpctencaq>

Thus, I'm adding a warning statement to the end of the description of 
"filename", pointing out the implementation problems:

        Note: Many user agents do not properly handle escape characters
        when using the quoted-string form.  Furthermore, some user agents
        erroneously try to perform unescaping of "percent" escapes (see
        Appendix C.2), an thus might misinterpret filenames containing he
        percent character followed by two hex digits.

(see <http://trac.tools.ietf.org/wg/httpbis/trac/changeset/1041>).

Best regards, Julian

---

From: Julian Reschke <[email-masked]>
Date: Thu, 21 Oct 2010 14:55:46 +0200

> <http://trac.tools.ietf.org/wg/httpbis/trac/changeset/1024>.

I should have mentioned what I added:

"Parameter names MUST NOT be repeated; a header field value with 
multiple instances of the same parameter &SHOULD; be treated as invalid."

This goes a bit further than post HTTP header field definitions in 
saying "SHOULD be treated as invalid", which is equivalent to "SHOULD 
NOT do error recovery".

Maybe this should be reduced to a simple statement of fact ("is 
invalid"), without requiring any specific behavior (*)?

Best regards, Julian

(*) I understand that some among us believe that error handling needs to 
be specified; but *if* we do this (and I don't think we should), we 
should be consistent in doing that.

---

From: Nicolas Alvarez <[email-masked]>
Date: Thu, 21 Oct 2010 23:04:10 -0300

>         percent character followed by two hex digits.

containing he -> containing the? Or maybe "containing *a* percent 
character"?

-- 
Nicolas

---

From: Julian Reschke <[email-masked]>
Date: Fri, 22 Oct 2010 10:45:34 +0200

> containing he ->  containing the? Or maybe "containing *a* percent

I meant "the"; the typo happened when composing the mail (that being 
said, when checking the doc I found *another* typo :-)

Thanks for catching this.

Best regards, Julian