Re: [PATCH 3/4] worktree add: add --orphan flag

[Eric Sunshine <sunshine@sunshineco.com>]

On Fri, Nov 4, 2022 at 12:42 PM Jacob Abel <jacobabel@nullpo.dev> wrote:
> On 22/11/04 01:03AM, Eric Sunshine wrote:
> > On Thu, Nov 3, 2022 at 9:07 PM Jacob Abel <jacobabel@nullpo.dev> wrote:
> > Are we sure we want to be modeling this after `git checkout --orphan`?
> > If I understand correctly, that option has long been considered (by
> > some) too clunky, which is why `git switch --orphan` was simplified to
> > accept only a branch name but no commit-ish, and to start the orphan
> > branch with an empty directory. My own feeling is that modeling it
> > after `git switch --orphan` is probably the way to go...
>
> I would argue that the `git checkout --orphan` command format is preferable to
> `git switch --orphan` when creating new worktrees. Reason being that in many
> cases (except when working in a new repo), if you are trying to create a
> worktree from an orphan you will be doing it with a different commit-ish
> currently checked out in your worktree than the one you want to use for the
> orphan (or you aren't in any worktree).

I guess I'm not understanding the use-case being described here or
that this series is trying to address. In my own experience, the very,
very few times I've used --orphan was when I needed a branch with no
existing history (i.e. "orphan") and with no existing files. For that
use-case, `git switch --orphan` is ideal, whereas `git checkout
--orphan` is a bother since it requires manually removing all content
from the directory and clearing the index.

> Requiring the commit-ish to be inferred would limit the user to checking out
> an orphan from an existing worktree (in which case they could just create a
> new worktree normally and use `git switch --orphan` to move that to an orphan
> branch).

I'm not following what you mean by inferred commit-ish. `git switch
--orphan` does not infer any commit-ish; it starts the orphaned branch
with an empty directory, hence there is no commit-ish involved.

The `git switch --orphan` behavior was intentionally implemented to
"fix" what has long been considered (by some) a UX botch in the
behavior of `git checkout --orphan`. It was argued that in the vast
majority of cases, people wanted an orphan branch to mean both "no
history" and "no files". So, in that sense, it feels like a step
backward to adopt `git checkout --orphan` when introducing `git
worktree --orphan`.

But, as I said, I'm genuinely not grasping your use-case, so I'm
having trouble understanding why you consider `git checkout --orphan`
a better model. If you can elaborate your use-case more thoroughly,
perhaps it would help (at least me).