[Ksummit-discuss] [TOPIC] Metadata addendum to git commit

[Takashi Iwai]

At Thu, 22 May 2014 08:28:37 +0200,
Johan Herland wrote:
> 
> On Thu, May 22, 2014 at 7:58 AM, Takashi Iwai <tiwai at suse.de> wrote:
> >> From: Junio C Hamano <gitster at pobox.com>:
> >> A good way forward to solve Iwai-san's original issue might be
> >>
> >>  * Establish the "Fixes:" mentioned above as a standard practice.
> >>    Polishing Christian's interpret-trailers tool might be a good way
> >>    to encourage developers to do so.
> >>
> >>  * Have an easy way for developers to scan incoming commits for
> >>    these "Fixes:" footer, and record the reverse mapping locally, so
> >>    that we can go from a commit whose brokenness is discovered later
> >>    to the commit that fixes its breakage efficiently.  "notes" may
> >>    be a good mechanism to implement this mapping, and we do not have
> >>    to worry about sharing the notes trees among developers.
> >>
> >>  * The information is visible with "log --show-notes" if it is
> >>    stored in local notes.  When an earlier commit that was later
> >>    found to be broken is shown, the note that points at the commit
> >>    that fixes it will be shown.
> >>
> >>  * Teach "bisect" to also take notice of this information, and
> >>    temporarily cherry-pick while testing commits with fixes that
> >>    were discovered later, in a way similar to what was suggested by
> >>    Jiri Kosina in an earlier message.
> >
> > These sound like a good plan, indeed.
> >
> > But, one missing, and maybe often happening thing is: people forget to
> > tag at the right time.  In the scenario above, if a maintainer forgets
> > to add Fixes: tag in the fix commit, it's all gone?
> 
> Yes, unless you add it (using git-notes) as an annotation to the fix
> commit, but then you're back to the (perceived) problem of sharing
> those notes.
> 
> Alternatively, you would have to find a different mechanism for
> developers to insert entries into their reverse mappings from
> post-facto/missing "Fixes:" tags.

After reconsidering this, now I don't think we can rely only on Fixes
tag.  The addendum notes are useful for other purposes, e.g. finding
external links.  And, yet one useful thing by addendum is that you can
mark the regression no matter whether it's already fixed or not.  With
Fixes-tag reverse mapping, you can find only fixed regressions, but
not open regressions.

So, we seem back to square now :)

Like Christian mentioned, what about some way to push / pull git notes
in a trusted way?  If we apply the maintainer model also for managing
such information, too, the similar mechanism would be required.

Or, better to manage such information in a totally different manner
(e.g. a web API)?


Takashi