Re: [RFC PATCH] `log --merge` also for rebase/cherry pick/revert

From: Michael Lohmann <mi.al.lohmann@gmail.com>
Date: Jan 12, 2024, 15:03 UTC
Message-ID: <20240112150346.73735-1-mi.al.lohmann@gmail.com>
In-Reply-To: <47a4418b-68bf-4850-ba8b-1a5264f923e4@gmail.com>

Hi Phillip,

On 12. Jan 2024, at 12:01, phillip.wood123@gmail.com wrote:

> I should start by saying that I didn't know "git log --merge" existed before
> I saw this message

I also just found it and it looked very useful...

Show 10 quoted lines

> so please correct me if I've misunderstood what this patch is doing. If I
> understand correctly it shows the commits from each side of the merge and is
> equivalent to
> 
>    git log HEAD MERGE_HEAD ^$(git merge-base HEAD MERGE_HEAD)
> 
> When a commit is cherry-picked the merge base used is CHERRY_PICK_HEAD^ [*]
> so I'm not sure what
> 
>    git log HEAD CHERRY_PICK_HEAD ^$(git merge-base HEAD CHERRY_PICK_HEAD)

Almost, but not quite: "git log —merge" only shows the commits touching the conflict, so it would be equivalent to (I think):

   git log HEAD CHERRY_PICK_HEAD ^$(git merge-base HEAD CHERRY_PICK_HEAD) -- $(git diff --name-only --diff-filter=U --relative)

(or replace CHERRY_PICK with one of the other actions)

> Indeed there HEAD and CHERRY_PICK_HEAD may not share a common ancestor.

True - but same for MERGE_HEAD ("git merge --allow-unrelated-histories"). I have to confess I did not check how it would behave under those circumstances. It could either error, or (more helpful) show the log touching the file until the root commit.

Best wishes Michael