Re: [PATCH] merge: --ff-one-only to apply FF if commit is one

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 31, 2023, 00:19 UTC
Message-ID: <xmqq1qdb8wzk.fsf@gitster.g>
In-Reply-To: <ZUALkdSJZ70+KBYq@nand.local>

Taylor Blau <me@ttaylorr.com> writes:

Show 15 quoted lines

> This seems like a pretty niche feature to want to introduce a new option
> for. I would imagine the alternative is something like:
>
>     ff="--no-ff"
>     if test 1 -eq $(git rev-list @{u}..)
>     then
>         ff="--ff"
>     fi
>
>     [on upstream @{u}]
>     git merge "$ff" "$branch"
>
> I don't have a great sense of how many users might want or benefit from
> something like this. My sense is that there aren't many, but I could
> very easily be wrong here.

Another more fundamental objection is "Why do we special case only a singleton commit?"

Why isn't a trivial two-patch series also OK to fast-forward? Three? There is no inherent reason to draw a line on one commit topic---given that a single commit could be a large and involved one that could have been a multi commmit series.

And you cannot decide if the "topic" is large enough to deserve a binding merge commit even if it is a single commit topic, or if is small enough and you want to allow fast-forward, without looking at it first. So from that point of view, too, I do not think this new option is a good idea. Let's not add an option to encourage a bad discipline.

Thanks.