Subject: Re: bug#65352: Fix time-machine and network

From: Simon Tournier <[email-masked]>
Date: Thu, 17 Aug 2023 18:08:38 +0200

Hi Maxim,

On Thu, 17 Aug 2023 at 17:42, Maxim Cournoyer <[email-masked]> wrote:

> >                       (match ref
> > -                       ((or ('commit . commit)
> > -                            ('tag-or-commit . commit))
> > +                       (('tag-or-commit . commit)

> Not that channel-list is a public API, so this is effectively changing
> the contract, no?

Well, the contract is not clearly defined. ;-)

The REF is defined by the docstring of update-cached-checkout,

  REF is pair whose key is [branch | commit | tag | tag-or-commit ] and value
  the associated data: [<branch name> | <sha1> | <tag name> | <string>].
  If REF is the empty list, the remote HEAD is used.

Therefore, if we want to be compliant with the public API, we also
need to add 'tag' to the 'or' match case; as I suggested when
commenting your patch tweaking this part. :-)

Well, from my point of view, the alternative is:

 a)
                     (match ref
                       (('tag-or-commit . commit)
                        (channel (inherit c)
                                 (url url) (commit commit) (branch #f)))
                       (('branch . branch)
                        (channel (inherit c)
                                 (url url) (commit #f) (branch branch)))
                       (#f
                        (channel (inherit c) (url url))))

or b)
                     (match ref
                       ((or ('commit . commit)
                            ('tag-or-commit . commit)
                            ('tag . commit))
                        (channel (inherit c)
                                 (url url) (commit commit) (branch #f)))
                       (('branch . branch)
                        (channel (inherit c)
                                 (url url) (commit #f) (branch branch)))
                       (#f
                        (channel (inherit c) (url url)))))

but not ecab937897385fce3e3ce0c5f128afba4304187c. :-)

Cheers,
simon