Re: [PATCH v3] worktree add: shouldn't dwim if -b or -B is given

[Junio C Hamano <gitster@pobox.com>]

"Yoichi NAKAYAMA via GitGitGadget" <gitgitgadget@gmail.com> writes:

> From: Yoichi NAKAYAMA <yoichi.nakayama@gmail.com>
>
> 'git worktree add <path> <branch>' DWIMs <branch> to a
> remote-tracking branch when neither -b, -B, nor --detach
> is given.
>
> However, 'git worktree add -b <new-branch> <path> <branch>' can
> still DWIM <branch>, causing <new-branch> to be ignored.
>
> This is a regression introduced in v2.42.0
> (128e5496b325640f0a09cc1d5b1e346c069b410f).

I'll commit with the latter half of the above message rewritten like
this:

    However, 'git worktree add -b <new-branch> <path> <branch>' can
    still DWIM <branch>, causing <new-branch> to be ignored.  This is a
    regression introduced by 128e5496b3 (worktree add: extend DWIM to
    infer --orphan, 2023-05-17), which appeared in Git 2.42.

As we refer to an individual commit using "log -1
--pretty=reference" format.

> Signed-off-by: Yoichi NAKAYAMA <yoichi.nakayama@gmail.com>
> ---
>     worktree add: shouldn't dwim if -b or -B is given

The change looks good to me.

Thanks.

>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-2192%2Fyoichi%2Fworktree-add-should-not-dwim-with-b-v3
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-2192/yoichi/worktree-add-should-not-dwim-with-b-v3
> Pull-Request: https://github.com/gitgitgadget/git/pull/2192
>
> Range-diff vs v2:
>
>  1:  b00f6c2fa1 ! 1:  477ea27c8b worktree add: shouldn't dwim if -b or -B is given
>      @@ Metadata
>        ## Commit message ##
>           worktree add: shouldn't dwim if -b or -B is given
>       
>      -    git worktree add <path> <branch> DWIMs <branch> to a
>      +    'git worktree add <path> <branch>' DWIMs <branch> to a
>           remote-tracking branch when neither -b, -B, nor --detach
>           is given.
>       
>      -    However, git worktree add -b <new-branch> <path> <branch> can
>      +    However, 'git worktree add -b <new-branch> <path> <branch>' can
>           still DWIM <branch>, causing <new-branch> to be ignored.
>       
>           This is a regression introduced in v2.42.0
>
>
>  builtin/worktree.c      | 22 ++++++++++++----------
>  t/t2400-worktree-add.sh | 10 ++++++++++
>  2 files changed, 22 insertions(+), 10 deletions(-)
>
> diff --git a/builtin/worktree.c b/builtin/worktree.c
> index 654d27c3e1..cc46c1b415 100644
> --- a/builtin/worktree.c
> +++ b/builtin/worktree.c
> @@ -898,16 +898,18 @@ static int add(int ac, const char **av, const char *prefix,
>  		/* DWIM: Infer --orphan when repo has no refs. */
>  		opts.orphan = (!s) && dwim_orphan(&opts, !!opt_track, 1);
>  	} else if (ac == 2) {
> -		struct object_id oid;
> -		struct commit *commit;
> -		char *remote;
> -
> -		commit = lookup_commit_reference_by_name(branch);
> -		if (!commit) {
> -			remote = unique_tracking_name(branch, &oid, NULL);
> -			if (remote) {
> -				new_branch = branch;
> -				branch = new_branch_to_free = remote;
> +		if (!new_branch) {
> +			struct object_id oid;
> +			struct commit *commit;
> +			char *remote;
> +
> +			commit = lookup_commit_reference_by_name(branch);
> +			if (!commit) {
> +				remote = unique_tracking_name(branch, &oid, NULL);
> +				if (remote) {
> +					new_branch = branch;
> +					branch = new_branch_to_free = remote;
> +				}
>  			}
>  		}
>  
> diff --git a/t/t2400-worktree-add.sh b/t/t2400-worktree-add.sh
> index 87b926728a..ba3bec078f 100755
> --- a/t/t2400-worktree-add.sh
> +++ b/t/t2400-worktree-add.sh
> @@ -621,6 +621,16 @@ test_expect_success '"add" <path> <branch> dwims' '
>  	)
>  '
>  
> +test_expect_success '"add" <path> <branch> does not dwim with -b' '
> +	test_when_finished rm -rf repo_upstream repo_dwim wt &&
> +	setup_remote_repo repo_upstream repo_dwim &&
> +	(
> +		cd repo_dwim &&
> +		test_must_fail git worktree add -b branch ../wt foo 2>actual &&
> +		test_grep "^fatal: invalid reference: foo" actual
> +	)
> +'
> +
>  test_expect_success '"add" <path> <branch> dwims with checkout.defaultRemote' '
>  	test_when_finished rm -rf repo_upstream repo_dwim foo &&
>  	setup_remote_repo repo_upstream repo_dwim &&
>
> base-commit: 5b2471720c93ee30e5764a19f3d3b3ae9ec9712a