Re: `about-emacs' - what about the revno?

[Teemu Likonen <tlikonen@iki.fi>]

* 2010-08-28 18:57 (+0300), Eli Zaretskii wrote:

> "Drew Adams" wrote:
>> If the "revno" is important info for identifying an Emacs build, then
>> perhaps we should include it in such user-facing info. If not, then
>> perhaps developers could refer in some other way (by date?) to the
>> code that contains a given fix.
>
> This has come up before, but the discussion was inconclusive (IIRC)
> because of 2 reasons:
>
>   . revno is not unique: two different branches can have the same
>     revno for two very different code bases
>
>   . revision-id, an alternative method of specifying a revision, _is_
>     unique, but it's long and a mouthful:
>
>             eliz@gnu.org-20100828152310-v42vqrt01k788siu

Another reason to use Git instead. With "git describe" you get unique
commit identifiers which are also human-readable and have an increasing
commit counter in it, for example:

    v23.2-54-g1234ab

It consists of the latest tag name (e.g., "v23.2") which is reachable
from the current commit, the commit count (54) after the tag and an
abbreviated SHA1 ID of the current commit (1234ab).

Some projects that use Git include such a version string automatically
to program's build. Git commands understand the string as a version
identifier. When executing "git describe" on a tagged commit it outputs
just the tag name (e.g., "v23.2") so it automatically gives the right
answer for releases too (can be useful when creating release tarballs).

Sorry for pushing Git again but it's just better.

> In general, a bugfix should appear in the ChangeLog files with the bug
> number, so you should be able to track bugfxes that way.

More elegant way is to write something like "Closes: bug#1234" in the
appropriate commit message and have the central Emacs repository use a
post-receive hook script that will detect the keyword in commit
messages. The hook script could then send control message to the bug
tracker and close the bug with a message like this:

    This issue has been fixed by the commit

        Commit: v23.2-57-gab1cd2
        Author: Dave Developer <email@internet.invalid>
        Date:   2010-00-00 00:00:00 +0000

    You can use command "git show v23.2-57-gab1cd2" in the Emacs Git
    repository to see the details.