Re: [PATCH 2/2] worktree: reject empty string

From: René Scharfe <l.s.r@web.de>
Date: Aug 2, 2026, 06:26 UTC
Message-ID: <f6b7af1a-29fd-4bec-b819-34b7962180fb@web.de>
In-Reply-To: <ec682d75f3a7848dc36f82cf36bbdff6fd283e2d.1784978348.git.gitgitgadget@gmail.com>

On 7/25/26 1:19 PM, Matthias AÃhauer via GitGitGadget wrote:

Show 26 quoted lines

> From: =?UTF-8?q?Matthias=20A=C3=9Fhauer?= <mha1993@live.de>
> 
> `git worktree add ""` errors out with the message `BUG: How come ''
> becomes empty after sanitization?`, but not due to a bug in the
> sanitization code. An empty string should remain empty during
> sanitization. Instead reject the argument as invalid user input,
> if it's already empty before sanitization.
> 
> Signed-off-by: Matthias Aßhauer <mha1993@live.de>
> ---
>  builtin/worktree.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/builtin/worktree.c b/builtin/worktree.c
> index d8188035db..113dbf98d3 100644
> --- a/builtin/worktree.c
> +++ b/builtin/worktree.c
> @@ -496,6 +496,8 @@ static int add_worktree(const char *path, const char *refname,
>  		die(_("invalid reference: %s"), refname);
>  
>  	name = worktree_basename(path, &len);
> +	if (!len)
> +		die(_("the empty string is not a valid worktree"));
>  	strbuf_add(&sb, name, path + len - name);
>  	sanitize_refname_component(sb.buf, &sb_name);
>  	if (!sb_name.len)

Hmm, on my machine, with or without this patch:

   $ git worktree add ""
   Preparing worktree (new branch '')
   fatal: '' is not a valid branch name
   hint: See 'git help check-ref-format'
   hint: Disable this message with "git config set advice.refSyntax false"

and

   $ git worktree add /
   Preparing worktree (new branch '')
   fatal: '' is not a valid branch name
   hint: See 'git help check-ref-format'
   hint: Disable this message with "git config set advice.refSyntax false"

This error message is produced by the command 'git branch "" HEAD' issued using run_command() in add(), just before the the add_worktree() call, which is then skipped.

René