Re: [Nmh-workers] Changes to forw(1)

[Ralph Corderoy]

Hi Ken

> I admit I am not clear where Ralph stands on this particular issue;
> perhaps the Marmite shortage is affecting things :-)

Marmite's basic ingredient is yeast sludge, a waste product from brewing
beer.  Give me the beer.  It's solely produced in Burton, which used to
have a large beer-brewing industry.  "Come friendly bombs and fall on
Burton!"  It's on my target list just above Twiglets.

> Ralph's not so crazy on letting those headers get out, but he never
> said that he wanted or didn't want a Nmh- prefix.

http://lists.nongnu.org/archive/html/nmh-workers/2016-10/msg00096.html
I think `Nmh-' prefix is better on these nmh-directive headers if
everything else stays working as today.

I wandered off onto other options to try and trigger ideas that might be
acceptable to both camps.  And widen the problem a bit to consider
something that helps, or at least doesn't hinder, other problems.

Ideally,

    Allow the user to write any legal header and have it hit the wire.
    Ensure nmh-directive headers don't leak.
    Ensure nmh-directive headers don't clash with external headers.
    Catch typos in header names so they don't hit the wire.

Starting to use Nmh- from now on, having Nmh-* stripped by post(8), does
some of that.  Another alternative would be to consider all headers to
be nmh's fare; the user cannot put `Foo: bar' in a draft.  This would
mean we can continue to dribble over the namespace over time since it's
ours, all ours.  We can catch corruptions, `Subjct'.  And post can
ensure only known headers reach the wire, after correct encoding has
been applied.

The `escape' so users can still add their own headers could be another
nmh-directive header, e.g. «Wire: Foo: Bar».  I don't think any valid
header line from a user is an invalid header value, so it can just have
a new header key prefixed?  (I'd probably go for `X' for external to
save the clutter.)

> Also ... if we are having post(8) scrub out headers with an Nmh-
> prefix, we could also have it scrub out any header, like Attach:,

No, because users may have a reason to add headers unknown to nmh.

> we could have it put in a X-Mailer or User-Agent header.  It looks
> like that was never standardized for Email, but it comes from HTTP and
> there was an Internet-Draft here to use it for Email:
> 
> https://tools.ietf.org/html/draft-melnikov-email-user-agent-00

"This Internet-Draft will expire on April 24, 2014."  Also,
https://datatracker.ietf.org/doc/search/?name=melnikov&sort=&rfcs=on&activedrafts=on&by=group&group=
doesn't list it or an RFC conversion.

-- 
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy