Re: Limitations of Emacs' vc when using modern backends

[Juliusz Chroboczek]

>> (3) Darcs identifies revisions by a 65-character long hash of a bunch
>> of data, which is not something you want to type.  Because of that,
>> vc-darcs allows identifying a revision by a number of different means
>> (see vc-darcs-rev-to-hash if you want the gory details).

> Is this specific to vc-darcs or to darcs?  Could you show what it
> does concretely?

Right now, the penultimate revision of vc-darcs.el happens to be

  20051116215244-4cc09-4d8edc6c60cacc62a56bb4480ee9cd80be414c18

Obviously, we don't require the user to remember this; what we do is
that we allow the user to type:

 - any prefix of the revision hash;
 - any prefix of the log message.

If multiple revisions match, the latest one is chosen.

(I'm simplifying somewhat, but that will do for the discussion at hand.)

So I'd usually type ``Update version number to 1.6'', or ``Update
version'' or even just ``Update''.  With the current version of
vc-darcs, I end up with multiple buffers called

  vc-darcs.el~Update
  vc-darcs.el~Update version
  etc.

What I'm asking is the means to have vc-darcs.el normalise such
non-canonical revision identifiers to the canonical hash.

                                        Juliusz