Re: [Q] rebase -i: turn "pick" to "edit", make no change, what should happen?

From: Marc Branchaud <marcnarc@xiplink.com>
Date: May 17, 2024, 12:42 UTC
Message-ID: <6620412e-a8ea-40fb-8823-13c4b33e9808@xiplink.com>
In-Reply-To: <xmqqy189o94c.fsf@gitster.g>

On 2024-05-16 15:21, Junio C Hamano wrote:

Show 9 quoted lines

> What should happen when I turn "pick" to "edit" in a "rebase -i"
> session, check what got checked out in the working tree, find it
> satisfactory and decide not to make any change to the files, and say
> "rebase --continue"?
> 
> The current implementation seems to just move to the next step,
> without offering a chance to edit the log message.  I do not know
> offhand if this is something we changed recently, or if it has been
> that way forever.

It's been this way forever (or close enough; I've been using Git since ~2010).

Show 10 quoted lines

> I personally found this a bit unintuitive, because in my metal
> model, "reword" is a mere subset of "edit": the latter would give me
> chances to change both the contents and the log, while the former
> only would offer me a chance to change the log.
> 
> But the actual behaviour does not match that mental model.  "edit"
> is purely about editing the worktree files, and only if files (hence
> the tree recorded) are modified, a chance to edit the log is offered
> to adjust the message to what the new tree brings on top of the
> parent commit.

My mental model has always been that "edit" means "amend" -- when I tell "git rebase" I want to "edit" a commit it (usually) means I intend to "git commit --amend" it in some fashion, whether that's to update the tree the commit changes, or to tweak the message, or both. (Or something else entirely -- since I'm at the shell prompt, I can do anything! The power!)

I like that "edit" does not open the editor if I decide not to change any files, but does open it if I do change any files (and that "git rebase" does the amending for me if I just stage the changes and say "git rebase --continue"). Seeing the editor after I say "git rebase --continue" is also a good reminder to me that I've changed something in the tree being committed. I've found this helpful if I've been distracted during a rebase session.

If I *know* that I only want to edit the message, then I say "reword".

> Of course, we can work it around with "git rebase --edit-todo"
> before saying "git rebase --continue".

Or, more directly, just "git commit --amend".

Show 8 quoted lines

> But the current behaviour
> somehow feels optimized for a wrong case.  Admittedly, it is logical
> that it does not offer a chance to edit the log message if we did
> not make any change to the working tree.  After all, the reason why
> it may become necessary to edit the log is because the user made
> some changes to the tree in the first place.  And by not opening the
> editor, only to close it without making any change, the command is
> saving the user some keystrokes.

Yes, and I've always appreciated this behaviour.

M.

Show 5 quoted lines

> But given that saying "edit" and not making any changes is a rare
> case, it feels wrong thing to optimize for.
> 
> Anyway.
>