Re: Referring to revisions in the git future.

[Óscar Fuentes]

Alan Mackenzie <address@hidden> writes:

> We've more than one branch in our Emacs repository, yet the bzr revision
> numbers are not in the slightest inconvenient.

Expressions like this, taken from your original message:

    "That was fixed in revision 118147, have you updated since then?"

are not useful unless the branch is known. And then, if I wish to know
if that fix was merged into another branch, I'm forced to obtain the
message id.

Rev numbers are only useful when the community works with a CVS-like
workflow.

>> As you use Mercurial, which has revision numbers, the advice of the
>> Mercurial experts possibly have some weight for you:
>
>> http://mercurial.selenic.com/wiki/RevisionNumber
>
>>     Revision numbers referring to changesets are very likely to be
>>     different in another copy of a repository. Do not use them to talk
>>     about changesets with other people. Use the changeset ID instead.
>
> That is a bit like saying, instead of saying "tomorrow at 8 o'clock",
> which is horribly ambiguous, you should instead say at time 238707724383
> (i.e. number of seconds after 1970-01-01, or whenever it was).  Changeset
> IDs are good for some things, bad for others.

Yes, one of the inconveniences of changeset ids are that they are just
that: ids, without any other info. OTOH it is trivial to obtain any info
from the id alone (author, date, diff, branches that include it, etc)
with a simple Emacs trick. That does not apply to rev numbers.

>> OTOH, there was some discussion on this list about using some
>> tool-independent schema, using a combination of the author's e-mail and
>> a timestamp.
>
> Are they going to enable the sort of conversation I exemplified above?

As they would contain a human-readable timestamp, yes, essentially. But
the timestamp was, precisely, the trickiest part to get right.