Subject: #1178 Whitespace in Path header

From: Harald Alvestrand <[email-masked]>
Date: Fri, 03 Mar 2006 16:51:56 +0100

There has been no discussion on this ticket (that I remember) since my 
last summary, where my status note was "Consensus is not clear to me".

Does anyone wish to attempt to present a possible consensus text?

                  Harald

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From: "Charles Lindsey" <[email-masked]>
Date: Mon, 6 Mar 2006 13:22:34 GMT

>Does anyone wish to attempt to present a possible consensus text?

Hmmmmmm! How did this issue come to be associated with the Path header?
The text mentioned in the ticket, which currently sits in USEPRO, related
to the Newsgroups header. But actually, the matter arises with Newsgroups,
Distribution and Path.

The text currently written for Newsgroups (3.1.5) is misleading, as I am
sure I have pointed out before.

Currently, it says:

   Folding the Newsgroups header field over several lines has been shown
   to harm propagation significantly.  Folded Newsgroups header fields
   SHOULD NOT be generated, but MUST be accepted.

Which does not make it clear that this folding is newly introduced, and
moreover the effects of introducing it suddenly would be far worse than
"harming propagation significantly".

So what it needs in 3.1.5 is something like:

   The possibility to fold this header field is newly introduced by this
   standard, and would have a severe impact on propagation if introduced
   prematurely. Therefore, although FWS MUST be accepted where required by
   the syntax above, it SHOULD NOT be generated at the present time. This
   restriction may well be removed in a future version of this standard.

The effects of introducing it in the Distribution and Path headers are
much less severe (even benign in the Path case). Moreover, it was arguably
permitted by RFC 1036 in the Path case. So the wording there need not be
so harsh.

So in 3.2.7 (Distribution) you could write:

   Folding of this header field may result in <dist-name>s being ignored
   in the folded lines by some current news servers. Therefore, although
   FWS MUST be accepted where required by the syntax above, it SHOULD NOT
   be generated at the present time. This restriction may well be removed
   in a future version of this standard.

And similarly in 3.1.6 (Path):

   Folding of this header field may result in <whatever-we-call-them>s
   being ignored in the folded lines by some current news servers.
   Therefore, although FWS MUST be accepted where required by the syntax
   above, it SHOULD NOT be generated at the present time. This restriction
   may well be removed in a future version of this standard.

Actually, that last one may still be too strong. USEPRO currently
encourages you to fold the Path header, and Frank's comment in the ticket
seems to want to retain that. So we need to decide it now so that USEPRO
can be made to fit later. One might even remove all mention of it in
USEFOR (recall that the worst that can happen if a Path gets folded at the
present time is that some article may get sent to a server that already
has it.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131 Fax: +44 161 436 6133   Web: http://www.cs.man.ac.uk/~chl
Email: [email-masked]      Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K.
PGP: 2C15F1A9      Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5

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From: Frank Ellermann <[email-masked]>
Date: Mon, 06 Mar 2006 19:30:48 +0100

> Does anyone wish to attempt to present a possible consensus

Already posted in <[email-masked]> or
<news://news.gmane.org/[email-masked]>

~~~ cut ~~~
> 1178: USEFOR 3.1.6: Whitespace in Path header

>   Consensus is not clear to me.

Oops, that's a misleading title.  The issue is WSP in all of
Newsgroups, FollowupsTo, and Distribution:

Newsgroups: one, two, three

That doesn't work as expected on many servers, the blank after
the comma (any FWS).  USEPRO offers a note about this issue to
be moved to USEFOR.  For FollowupsTo and Disribution it's the
same issue, they only need a pointer to SHOULD NOT (or whatever
it is) for Newsgroups.

Or rather FollowupsTo is clear as soon as Newgroups is clear -
it's the same syntax.  So only Distribution needs a pointer.

~~~ end ~~~
                       Bye, Frank

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From: Harald Alvestrand <[email-masked]>
Date: Tue, 07 Mar 2006 17:44:58 +0100

Pilot error. I was searching for a ticket to capture the issue on 
whether to have folding whitespace in the Path: header before the !, 
after the !, between the !!, neither, or all, and it seems that I messed 
up the coupling between the article I quoted from and the issue - this 
should be two tickets, not one.

I'll change the subject header on this one.

---

From: "Charles Lindsey" <[email-masked]>
Date: Wed, 8 Mar 2006 13:58:59 GMT

>should be two tickets, not one.

I think we are agreed that we need to allow [FWS] at least _before_ every
"!" or "!!" (but not inside a "!!). I think that is what all the recently
proposed grammars do.

One might also allow it _after_ AS WELL. I do not hear much pressure for
that, and the ABNF would get a bit more complicated, but it could be done
if people want it so.