Question about pre-merge and git merge octopus strategy

Hi,

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.

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.

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?

-- ZheNing Hu