Re: [PATCH v2] merge-options.txt: correct wording of --no-commit option

[Elijah Newren <newren@gmail.com>]

On Tue, Feb 19, 2019 at 11:32 AM Junio C Hamano <gitster@pobox.com> wrote:
> Elijah Newren <newren@gmail.com> writes:
>
> > +With --no-commit perform the merge and stop just before creating
> > +a merge commit, to give the user a chance to inspect and further
> > +tweak the merge result before committing.
> > ++
> > +Note that fast-forward updates do not need to create a merge
> > +commit and therefore there is no way to stop those merges with
> > +--no-commit.  Thus, if you want to ensure your branch is not
> > +changed or updated by the merge command, use --no-ff with
> > +--no-commit.
>
> While the above is an improvement (so I'll queue it on 'pu' not to
> lose sight of it), I find the use of "do not need to" above somewhat
> misleading.  It solicits a reaction "ok, we know it does not need
> to, but it could prepare to create one to allow us to further muck
> with it, no?".
>
> IOW, a fast-forward by definition does not create a merge by itself,
> so there is nowhere to stop during a creation of a merge.  So at
> least:
>
>         s/do not need to/do not/

Yes, I agree that's a good change.  I'll wait a few days for other
feedback and resend with that and any other changes.

> It also may be a good idea to consider detecting this case and be a
> bit more helpful, perhaps with end-user experience looking like...
>
>   $ git checkout master^0
>   $ git merge --no-commit next
>   Updating 0d0ac3826a..ee538a81fe
>   Fast-forward
>     ...diffstat follows here...
>   hint: merge completed without creating a commit.
>   hint: if you wanted to prepare for a manually tweaked merge,
>   hint: do "git reset --keep ORIG_HEAD" followed by
>   hint: "git merge --no-ff --no-commit next".
>
> or even
>
>   $ git checkout master^0
>   $ git merge --no-commit next
>   warning: defaulting to --no-ff, given a --no-commit request
>   Automatic merge went well; stopped before committing as requested
>   hint: if you'd rather have a fast-forward without creating a commit,
>   hint: do "git reset --keep next" now.

Good points.  I thought of this last one before sending, though
without pre- and post- warnings/hints; without such text it definitely
seemed too magical and possibly leading to unexpected surprises in a
different direction, so I dismissed it without further thought.  But
the warnings/hints help.

> I do not have a strong preference among three (the third option
> being not doing anything), but if pressed, I'd say that the last one
> might be the most user-friendly, even though it feels a bit too
> magical and trying to be smarter than its own good.

I also lack a strong preference.  Maybe mark it #leftoverbits for
someone that does?

> In any case, the hint for the "recovery" procedure needs to be
> carefully written.

Yes.