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Date:   Mon, 3 Aug 2020 14:08:24 -0400
From:   Jeff King <peff@peff.net>
To:     Sergey Organov <sorganov@gmail.com>
Cc:     Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org,
        Chris Torek <chris.torek@gmail.com>
Subject: Re: [PATCH v2 0/7] making log --first-parent imply -m
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On Mon, Aug 03, 2020 at 06:47:20PM +0300, Sergey Organov wrote:

> > A command line option that takes _optional_ argument is evil; it
> > hurts teachability (e.g. "why does this option always require
> > "--opt=val" and refuses '--opt val'?").
> 
> Yeah, I sympathize.

Sorry, the optional argument was my suggestion. I don't think they're
that evil, but I agree they require extra knowledge for the user. I
don't mind avoiding them when possible (and it's definitely possible
here).

> > Introduce --diff-parent=(none|<parent-number>|c|cc|all) that is
> > different from --diff-merges, and -m and --[no-]diff-merges can be
> > defined in terms of that, at which point we can gradually deprecate
> > them if we wanted to, no?
> 
> Sounds great, I only hoped we can do it right now, with this new
> --diff-merges option, maybe as a pre-requisite to the patches in
> question, but Jeff said it's too late, dunno why.

It's too late for "-m" to change semantics (we could do a long
deprecation, but I don't see much point in doing so). But --diff-merges
is definitely still changeable until we release v2.29. My resistance was
mostly that I didn't want to complicate my series by adding new
elements. But we could do something on top.

-Peff