Re: New orphan worktree?

On Mon, Feb 22, 2021 at 7:17 PM Ævar Arnfjörð Bjarmason
[off-list ref] wrote:

On Tue, Feb 23 2021, Eric Sunshine wrote:

quoted

I'm not sure I follow. In git-switch, --orphan does not imply -c even
though --orphan also creates a new branch (thus seems to work similar
to -c); it is nevertheless mutually-exclusive with -c and -C. The same
goes for --orphan in git-branch.

I think we're on the same page with regards to what I meant. I.e. I
don't see how it makes sense to conflate the type of branch we want
(orphan or not orphan) with whether we want to clobber that branch or
not (switch -c or -C, or worktree -b or -B)

I see where you're coming from in viewing --orphan as a modifier of
branch creation rather than as a branch-creation option itself.
However, as far as UI is concerned, that ship sailed a long time ago,
I suppose.

quoted

As far as combining --orphan and -C (or -c), I'm not sure how we would
arrange that using the existing parse_options() mechanism. It seems
too magical and has potential for weird corner cases.

Isn't it just having --orphan be an OPTION_STRING with
PARSE_OPT_LASTARG_DEFAULT. I.e. to support:

    git switch -b branch --orphan
    git switch -B branch --orphan
    git switch --orphan branch

And:

    git worktree add -b branch --orphan
    git worktree add -B branch --orphan

I didn't test it, just skimmed the code.

I haven't dived into this stuff in a long time, but I'm having trouble
convincing myself that it would work out as intended. If I'm reading
PARSE_OPT_LASTARG_DEFAULT correctly, `git switch -b <branch> --orphan`
would not be the same as `git switch --orphan -b <branch>`, and I
don't think it would work at all for git-worktree-add which has
additional <path> and <commitish> arguments (i.e. `git worktree add -b
<branch> --orphan <path> [<commitish>]`).

Anyhow, as I responded elsewhere to Junio, my present leaning is
toward -b, -B, --orphan all being mutually-exclusive branch-creation
options, each taking a <branch> argument -- just like they are in
git-checkout and git-switch (-c/-C, in this case) -- and allowing
--force to overwrite an existing branch (in which case, -B can be
viewed as shorthand for `--force -b`).

quoted

Since git-worktree doesn't yet support --orphan, we certainly have
more leeway and could go with your proposal of having --orphan be
boolean and always requiring it to be used in conjunction with -b/-B.
However, I'm quite hesitant to take that approach since it breaks with
existing precedent in git-branch and git-switch, in which case
--orphan takes its own argument (<branch>) and is mutually-exclusive
with -b/-B/-c/-C.

In git-branch? Isn't it only git [checkout|switch] that takes --orphan?

Um, yes, I meant git-checkout everywhere I wrote git-branch. Sorry for
the confusion.

I think not having a -B or -C equivalent at all would be preferrable to
having a --force special-case just to work around the lack of it for
--orphan.

I'm having trouble wrapping my brain around this statement.