Re: On the nature of cover letters [WAS Re: [PATCH 0/6] Create Git/Packet.pm]

From: Jeff King <peff@peff.net>
Date: Nov 2, 2017, 07:22 UTC
Message-ID: <20171102072237.wbmrzrgfyxdb3m3v@sigill.intra.peff.net>
In-Reply-To: <CAGZ79kYghF6=AzL1N96fe2zixHCERXu=RpxHw2-kdUrU+j4CXw@mail.gmail.com>

On Wed, Nov 01, 2017 at 03:31:42PM -0700, Stefan Beller wrote:

Show 14 quoted lines

> On Wed, Nov 1, 2017 at 9:42 AM, Stefan Beller <sbeller@google.com> wrote:
> 
> >> So it may make more sense just to cross-reference those merges with the
> >> topics that spawned them on the mailing list. I.e., instead of copying
> >> the cover letter contents, just record the message-id (and update it
> >> whenever a new iteration of a topic is picked up via "git am"). That
> >> lets you get the cover letter information _and_ see any discussion
> >> or review around the patch.
> >
> > That sounds good.
> 
> Actually I just found out about `am.messageId`, which adds the individual
> message id as a footer. Maybe that is good enough? (Though it would
> clutter every commit, not just the merge commits)

It also means digging around to find the apex of the thread (though generally that can be done automatically with sufficiently smart tooling; I think public-inbox can do it pretty easily).

I also like the idea that I could read "log --first-parent" to get an overview of the topics (with links). But probably associating a message id with each patch smooths out a lot of corner cases (it sidesteps the "where do you store it until the commit is made" question, and it works when there's no cover letter). And it gives enough hint for other software to figure out everything else.

If the clutter is too much, it could also go into a git-notes ref (that's not already implemented, but it seems like it would be pretty easy to teach "git am" to do that).

For a while, Thomas Rast used a script to heuristically create that mapping via git-notes after the fact. But if "git am" just did it automatically on behalf of Junio, that would be more robust.

I will admit that I found I didn't use the mapping generated by Thomas's script all that much. But I do keep a local mailing list index and often search for the commit's subject as a mail subject, which roughly accomplishes the same thing.

-Peff