Re: Question about pre-merge and git merge octopus strategy

From: Christian Couder <christian.couder@gmail.com>
Date: May 6, 2022, 17:23 UTC
Message-ID: <CAP8UFD2p+Evqv_MBAgv23zooppsNWjOw6ZU2GLqAq_skZoJPOw@mail.gmail.com>
In-Reply-To: <CAOLTT8S8rh+VYcuaqBeNtmphiRqw7HropLFpkxfnTJq6BngGXw@mail.gmail.com>

Hi,

On Fri, May 6, 2022 at 10:15 AM ZheNing Hu <adlternative@gmail.com> wrote:

Show 7 quoted lines

> I am thinking about if git can "pre-merge" multiple branches, which
> can check if merge
> will have conflict, but not to merge them actually, like a option `--intend`.
>
> I find "git merge-tree" can output merge result in stdout, which meets
> my needs, but it can only
> support two branches' merge.

Elijah (added in Cc) has been working on "git merge-tree" improvements based on the new "ort" merge he developed. It supports merging 2 branches, but maybe there are ways to make it support more than 2.

> So I find git merge with more than two branches can use octopus strategy.
> What about git merge --no-commit? Which will not commit automatically,
> so we can check if they have
> confilct, and abort merge.

Yeah, I think that's what you want.

> I think it's not useful for git merge-octopus, because if we meet a
> merge conflict, we can't find
> MERGE_HEAD at all! How can we abort this conflict merge?

I don't know octopus merges much, but I think you should be able to abort using "git reset" (maybe with "--hard"). If the merge was performed using --no-commit or if there was a conflict, then I think it should be expected that there is no MERGE_HEAD as no commit would be created so MERGE_HEAD would have nothing to point to.