Re: [PATCH] commit: refuse to amend during conflict resolution

From: Elijah Newren <newren@gmail.com>
Date: Aug 27, 2026, 00:23 UTC
Message-ID: <CABPp-BETkvaRUvn36TxgnK4DW6agVbsiHe++FnJFhnRDfkge0A@mail.gmail.com>
In-Reply-To: <xmqqzey8j1gt.fsf@gitster.g>

On Wed, Aug 26, 2026 at 9:22 AM Junio C Hamano <gitster@pobox.com> wrote:

Show 26 quoted lines

>
> "Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
> > ...  However, with the merge backend of rebase we have to
> > be more careful, since it powers interactive rebases and
> >   - the interactive machinery internally uses `git commit --amend` for
> >     `squash` and `reword` directives
> >   - users are expected to `git commit --amend` after hitting an `edit`
> >     or `break` directive
> > So, we need to be careful with rebase to only reject amending when doing
> > conflict resolution.
>
> True.
>
> In addition, in any and all of these scenarios that lets the user
> deal with conflicts in his or her working tree files and record the
> result of conflict resolution in a commit, we should reject not only
> "git commit --amend" but also "git commit <paths>", shouldn't we?
>
> It may probably be better done in a separate topic, as the guiding
> principle is slightly different (i.e., "recording the conflict
> resolution is about recording the state on top of the current HEAD
> and never about updating the state recorded in the current HEAD" is
> the theme of the current topic.  "recording the conflict resolution
> is always about the entire tree" is the other topic), so we may want
> to leave a #leftoverbits marker here.

Oh, good callout. And later in commit.c we do disallow those, but only for the same operations we previously disallowed and amend during:

        commit_style = COMMIT_PARTIAL;

        if (whence != FROM_COMMIT) {
                if (whence == FROM_MERGE)
                        die(_("cannot do a partial commit during a merge."));
                else if (is_from_cherry_pick(whence))
                        die(_("cannot do a partial commit during a
cherry-pick."));
                else if (is_from_rebase(whence))
                        die(_("cannot do a partial commit during a rebase."));
        }

The exact same additional structure could apply there, and that kind of reinforces Phillip's suggestion to factor out a helper that we can call. I did that in v2.