Re: [PATCH] t1402: test forbidden characters in refnames

[Patrick Steinhardt <ps@pks.im>]

On Thu, Aug 13, 2026 at 08:43:56PM +0000, Nikolaus Schuetz via GitGitGadget wrote:
> From: Nikolaus Schuetz <nikolauspschuetz@gmail.com>
> 
> git-check-ref-format(1) documents that a refname cannot contain a
> space, tilde, caret, colon, question-mark, asterisk or open-bracket,
> and that it cannot be the single character "@".  Of these, only "?"
> was tested as a character embedded in an otherwise-valid refname;
> "*" was checked only as a lone character or with --refspec-pattern.
> 
> Add the remaining forbidden characters in that embedded form, and
> check that "@" alone is rejected even with --allow-onelevel -- where
> "@" is otherwise a valid refname component, as "refs/@" confirms.

Okay.

> diff --git a/t/t1402-check-ref-format.sh b/t/t1402-check-ref-format.sh
> index cabc516ae9..bc1e878a0f 100755
> --- a/t/t1402-check-ref-format.sh
> +++ b/t/t1402-check-ref-format.sh
> @@ -51,12 +51,20 @@ invalid_ref '.refs/foo'
>  invalid_ref 'refs/heads/foo.'
>  invalid_ref 'heads/foo..bar'
>  invalid_ref 'heads/foo?bar'
> +invalid_ref 'heads/foo~bar'
> +invalid_ref 'heads/foo^bar'
> +invalid_ref 'heads/foo:bar'
> +invalid_ref 'heads/foo*bar'
> +invalid_ref 'heads/foo[bar'
> +invalid_ref 'heads/foo bar'

This feels a tiny bit excessive, but I guess it does not hurt to enforce
this property, especially now that it's so easy to add new backends.

One thing I was briefly wondering is whether we could maybe have a
simple loop here, as this feels quite repetitive. We could for example:

    for c in '?' '~' '^' ':' '*' '[' ' '
    do
        invalid_ref "heads/foo${c}bar"
    done

By the way, one weird bit: is it intentional that all of these really
use "heads/something" instead of "refs/heads/something"? I guess it
ultimately doesn't matter.

>  valid_ref 'foo./bar'
>  invalid_ref 'heads/foo.lock'
>  invalid_ref 'heads///foo.lock'
>  invalid_ref 'foo.lock/bar'
>  invalid_ref 'foo.lock///bar'
>  valid_ref 'heads/foo@bar'
> +valid_ref 'refs/@'
> +invalid_ref '@' --allow-onelevel

This one certainly is a good addition, as these are quite a bit more
subtle.

Thanks!

Patrick