From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 28 Nov 2025 20:50:39 GMT
Subject: Re: [PATCH 0/1] replay: add --revert option to reverse commit changes
Message-ID: <xmqqtsydj2zk.fsf@gitster.g>
In-Reply-To: <CABPp-BF48AF9qoP_pUs1X=sUV-_G5BpsxnG6AEhQYkJkE_TBjA@mail.gmail.com>

Elijah Newren <newren@gmail.com> writes:

> How does one distinguish the "topic~5" in the range "topic~5
> topic~3..topic" from
>   * the topic~5 in "^topic~7 topic~5"

Two answers.

(1) You don't have to.  When you scan cmdline->rev[], you can notice
    the ^topic-7 form and reject, saying "we accept A..B but not ^A B."

(2) Or you design and document the interpretation you implement when
    you see a negative commit while you scan over cmdline->rev[].
    Perhaps you may make "^topic-7" to require a positive commit
    after it and convert "^topic-7 topic5" as if the user gave you a
    single "topic~7..topic~5".  Or you may do something else.

My assumption has been (1).


>   * the "topic1" and "topic2" in "^$OLD_COMMIT --ancestry-path topic1 topic2"

I haven't thought it through, but doesn't ancetry-path imply you are
really interested in the traditional connected set of commits?  The
path is a connected subset inside those commits after all, no?