Re: [PATCH v4 3/4] receive-pack: Protect current branch for bare repository worktree

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

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Hi Anders,

On Mon, 8 Nov 2021, Anders Kaseorg wrote:

> A bare repository won’t have a working tree at "..", but it may still
> have separate working trees created with git worktree. We should protect
> the current branch of such working trees from being updated or deleted,
> according to receive.denyCurrentBranch.
>
> Signed-off-by: Anders Kaseorg <andersk@mit.edu>
> ---
>  builtin/receive-pack.c |  4 +---
>  t/t5516-fetch-push.sh  | 12 ++++++++++++
>  2 files changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
> index cf575280fc..5a3c6d8423 100644
> --- a/builtin/receive-pack.c
> +++ b/builtin/receive-pack.c
> @@ -1452,8 +1452,6 @@ static const char *update_worktree(unsigned char *sha1, const struct worktree *w
>  	const char *retval, *git_dir;
>  	struct strvec env = STRVEC_INIT;
>
> -	if (is_bare_repository())
> -		return "denyCurrentBranch = updateInstead needs a worktree";
>  	git_dir = get_worktree_git_dir(worktree);
>
>  	strvec_pushf(&env, "GIT_DIR=%s", absolute_path(git_dir));
> @@ -1476,7 +1474,7 @@ static const char *update(struct command *cmd, struct shallow_info *si)
>  	struct object_id *old_oid = &cmd->old_oid;
>  	struct object_id *new_oid = &cmd->new_oid;
>  	int do_update_worktree = 0;
> -	const struct worktree *worktree = is_bare_repository() ? NULL : find_shared_symref("HEAD", name);
> +	const struct worktree *worktree = find_shared_symref("HEAD", name);

While `find_shared_symref()` currently won't return a `worktree` with a
non-zero `is_bare`, to future-proof the code we might want to turn the
`if (worktree)` below (8 lines outside the current diff context) into `if
(worktree && !worktree->is_bare)`.

>
>  	/* only refs/... are allowed */
>  	if (!starts_with(name, "refs/") || check_refname_format(name + 5, 0)) {
> diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
> index 2c2d6fa6e7..06cd34b0db 100755
> --- a/t/t5516-fetch-push.sh
> +++ b/t/t5516-fetch-push.sh
> @@ -1772,6 +1772,18 @@ test_expect_success 'denyCurrentBranch and worktrees' '
>  	test_must_fail git -C cloned push --delete origin new-wt
>  '
>
> +test_expect_success 'denyCurrentBranch and bare repository worktrees' '
> +	test_when_finished "rm -fr bare.git" &&

While `wt/` will be created inside `bare.git` and therefore be removed,
the branch `wt` won't. Maybe add `&& git branch -D wt`?

> +	git clone --bare . bare.git &&
> +	git -C bare.git worktree add wt &&
> +	test_commit grape &&

I like fruit, too! Apple, banana, grape, yummy. I wonder what's next :-)

> +	test_config -C bare.git receive.denyCurrentBranch refuse &&
> +	test_must_fail git push bare.git HEAD:wt &&
> +	test_config -C bare.git receive.denyCurrentBranch updateInstead &&
> +	git push bare.git HEAD:wt &&

Maybe make sure that `bare.git/wt/grape.t` exists? We do want the worktree
to be updated, after all...

Thanks,
Dscho

> +	test_must_fail git push --delete bare.git wt
> +'
> +
>  test_expect_success 'refuse fetch to current branch of worktree' '
>  	test_when_finished "git worktree remove --force wt" &&
>  	git worktree add wt &&
> --
> 2.33.1
>
>