bug#58472: [PATCH] Make `message-unique-id' less prone to collisions

[Stefan Kangas]

Matt Armstrong <matt@rfc20.org> writes:

> Since some tools expect users to work directly with Message-ID at
> times (https://notmuchmail.org/) it might be nice to avoid leading
> non-alnum chars,

I agree that it'd be nice to just use alpha-numeric characters.

> Maybe a base 62 encoder could be written just for this, as Emacs'
> version of this doesn't need to be fast.

A base62 encoder is just `message-number-base36' with the A-Z range
added.  I think I included that in a previous patch.

> Can a string be turned into a non-negative bignum integer in
> (simple) elisp?

Does this look reasonable?

    (seq-reduce (lambda (a i) (+ (ash a 8) i))
                (secure-hash 'md5 'iv-auto 128 nil t) 0)