Re: [PATCH 1/1] sequencer: fix empty commit check when amending

From: Junio C Hamano <gitster@pobox.com>
Date: Nov 22, 2019, 06:40 UTC
Message-ID: <xmqqh82w4do6.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <7d34c0ff805b8637b23d0ef0045370dfc931a3af.1574345181.git.gitgitgadget@gmail.com>

"Phillip Wood via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 7 quoted lines

> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> This fixes a regression introduced in 356ee4659b ("sequencer: try to
> commit without forking 'git commit'", 2017-11-24). When amending a
> commit try_to_commit() was using the wrong parent when checking if the
> commit would be empty. When amending we need to check against HEAD^ not
> HEAD.

Thanks.  That makes sense.

If you compare with HEAD and find there is no difference, that would mean that the "amend" itself is a no-op (i.e. the user said they want to make changes, but after all changed their mind)? It might be something worth noticing, but certainly not in the same way as "we were told to skip an empty commit---is this one empty?" gets treated.