Re: [PATCH] rebase -i: mark commits that begin empty in todo editor

[Bryan Turner <bturner@atlassian.com>]

On Thu, Apr 9, 2020 at 5:50 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> "Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
> > From: Elijah Newren <newren@gmail.com>
> >
> > While many users who intentionally create empty commits do not want them
> > thrown away by a rebase, there are third-party tools that generate empty
> > commits that a user might not want.  In the past, users have used rebase
> > to get rid of such commits (a side-effect of the fact that the --apply
> > backend is not currently capable of keeping them).  While such users
> > could fire up an interactive rebase and just remove the lines
> > corresponding to empty commits, that might be difficult if the
> > third-party tool generates many of them.  Simplify this task for users
> > by marking such lines with a suffix of " # empty" in the todo list.
> >
> > Suggested-by: Sami Boukortt <sami@boukortt.com>
> > Signed-off-by: Elijah Newren <newren@gmail.com>
> > ---
> >     rebase -i: mark commits that begin empty in todo editor
> >
> >     If this isn't enough, we could talk about resurrecting --no-keep-empty
> >     (and making --keep-empty just exist to countermand an earlier
> >     --no-keep-empty), but perhaps this is good enough?
>
> This does look like an unsatisfying substitute for the real thing,
> but perhaps looking for " # empty" and turning them a drop is simple
> enough?  Emacs types may do something like
>
>     C-x h C-u M-|
>     sed -e '/ # empty$/s/^pick /drop /'
>     <RET>
>
> and vi folks have something similar that begins with a ':'.
>
> But it would not beat just being able to say "--no-keep-empty" (or
> "--discard-empty"), would it?
>
> On the other hand, even if there were "--discard-empty" available,
> there may still be two classes of empty ones (e.g. ones that were
> created by third-party tools, the others that were deliberately
> empty) that the user may need and want to sift through, and for such
> a use case, the marking this patch does would be very valuable.
>
> So, from that point of view, this may not be enough, but a "throw
> away all" option is not enough, either.  We'd want to have both to
> serve such users better.

This was why I wondered whether it might be worth extending the
--empty option to add another possible value, like "drop-all", that
would allow the caller to say they want to drop all empty
commits--both those that started out empty and those that became
empty. That fourth mode would be distinct from the existing three.
(I'm not sure what to call said mode; "drop-all" looks odd alongside
the existing "drop". I just say "drop-all" here to help illustrate the
idea.)