Re: [PATCH 00/26] git-log: implement new --diff-merge options

From: Sergey Organov <sorganov@gmail.com>
Date: Dec 9, 2020, 19:44 UTC
Message-ID: <87k0tqdasa.fsf@osv.gnss.ru>
In-Reply-To: <xmqqpn3j32ka.fsf@gitster.c.googlers.com>

Junio C Hamano <gitster@pobox.com> writes:

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> By the time the change to make "--cc" imply "-p" was introduced, it
> was pretty much given that "-m -p" was useful to anybody, unless you
> are consuming these individual patches in a script or something like
> that.  So simply I didn't even think of making "-m" imply "-p".  It
> would be logical to make it so, but it would not add much practical
> value, I would have to say.

I need some help here.

Looking at the code and trying to follow the flow, I can't figure what rev->diff flag is for? Why rev->diffopt.output_format, that actually affects the output, is not enough?

My confusion originates from the fact that the code in revision.c sets rev->diff to 1 for -c/--cc , while it doesn't set it for -m, and this was the case *before* -c/--cc started to imply -p and -m.

It seems that the only place where rev->diff is tested is at the start of log_tree_diff(), and even there its absence could be ignored when rev->diffopt.flags.exit_with_status is set.

Is rev->diff an optimization, does it play another significant role, or is it a remnant?

Thanks, -- Sergey