Subject: Re: [PATCH v2 0/7] making log --first-parent imply -m

From: Sergey Organov <[email-masked]>
Date: Thu, 30 Jul 2020 00:41:39 +0300

Jeff King <[email-masked]> writes:

> On Tue, Jul 28, 2020 at 12:36:18PM -0400, Jeff King wrote:
>
>> This series just makes --first-parent imply -m. That doesn't change any
>> output by itself, but does mean that diff options like "-p", "-S", etc,
>> behave sensibly.

This is definitely step in the right direction, thanks a lot for working
on it!

>
> Here's a re-roll taking into account the discussion so far:
>
>   - the escape hatch option name is flipped to "--no-diff-merges" (with
>     "--diff-merges" matching "-m")

Rather than being just a synonym for -m, is there a chance for
"--diff-merges" implementation to be turned to output diff to the first
parent only, no matter if --first-parent is active or not?

Alternatively, may it have a parameter such as "-m parent-number" of
"git cherry-pick" being set to "1" by default?

This -m output of diffs to all the parents is in fact primary source of
confusion for me, even over all these mind-blowing inter-dependencies
between --first-parent, --cc, -c, -m, -p and what not. Who ever needs
these (potentially huge) diffs against other parents, anyway?

Introduction of this new option is a great opportunity for improvement
that would be a pity to miss.

Thanks,
-- Sergey