[Mailman-Developers] [Bug 985149] [NEW] Add List-Post value to permalink hash input

[Stephen J. Turnbull]

On Sat, Apr 21, 2012 at 1:22 AM, Barry Warsaw <barry at list.org> wrote:

> I think the hash value should be opaque.  Jeff can perhaps elaborate his
> use-case but I don't think the List-ID needs to be (or frankly *should* be)
> extractable from the hash, but instead just needs to inform the hash value.
> IOW, if you cross-post a message with Message-ID: <foo> to one at example.org and
> two at example.com, you'd get two different messages forwarded to the archives,
> and they would have different Permalink: hash values.  Before this proposal,
> they'd have the same value.

Which is a FAQ: how do I avoid getting two copies of the same message
from multiple lists I subscribe to?  If Mailman is maintaining a list
of messages received, with full personalization this FAQ now has an
acceptable answer.  If Mailman distinguishes the same message posted
to different lists in an opaque way, the answer is "we're sorry,
Mailman cannot do that by design."

Or do you see a way to do this that I don't?

> Of course, the List-ID itself should be preserved in the message that the
> archiver gets, so an archiver could still discriminate on that.

Not good enough, because the de-dupe db will store hashes AIUI.  If
the de-dupe db stores Message-IDs, then you have enough information.