Subject: Re: [PATCH 1/2] Make die_if_checked_out() ignore missing worktree checkouts.

From: SZEDER Gábor <[email-masked]>
Date: Thu, 17 Oct 2019 18:44:26 +0200

On Thu, Oct 17, 2019 at 12:28:25PM -0400, Peter Jones wrote:
> Currently if you do, for example:
> 
> $ git worktree add path foo
> 
> And "foo" has already been checked out at some other path, but the user
> has removed it without pruning, you'll get an error that the branch is
> already checked out.  It isn't meaningfully checked out, the repo's
> data is just stale and no longer reflects reality.
> 
> This makes it so that if nothing is present where a worktree is
> supposedly checked out, we ignore that the worktree exists, and let it
> get cleaned up the next time worktrees are pruned.
> 
> (I would prune it instead, but prune isn't available from libgit
> currently.)
> 
> Signed-off-by: Peter Jones <[email-masked]>
> ---
>  branch.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/branch.c b/branch.c
> index 579494738a7..60322ded953 100644
> --- a/branch.c
> +++ b/branch.c
> @@ -360,6 +360,9 @@ void die_if_checked_out(const char *branch, int ignore_current_worktree)
>  	wt = find_shared_symref("HEAD", branch);
>  	if (!wt || (ignore_current_worktree && wt->is_current))
>  		return;
> +	if (access(wt->path, F_OK) < 0 &&
> +	    (errno == ENOENT || errno == ENOTDIR))
> +		return;

I think this check is insuffient: even if the directory of the working
tree is not present, the working tree might still exist, and should
not be ignored (or deleted/pruned in the second patch).

See the description of 'git worktree lock' for details.

>  	skip_prefix(branch, "refs/heads/", &branch);
>  	die(_("'%s' is already checked out at '%s'"),
>  	    branch, wt->path);
> -- 
> 2.23.0
>