Re: [PATCH v4 3/9] stash: introduce is_stash_ref and assert_stash_ref functions.

> Introduce a function, is_stash_ref, which checks whether an
> argument is valid stash reference (e.g. is of the form ['refs/']stash['@{'something'}])
>
> Introduce a function, assert_stash_ref, which can be used to ensure
> that certain commands are only called with stash references as
> arguments.
>
> Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
> ---
>  git-stash.sh |    9 +++++++++
>  1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/git-stash.sh b/git-stash.sh
> index dbb7944..41a9359 100755
> --- a/git-stash.sh
> +++ b/git-stash.sh
> @@ -223,6 +223,15 @@ show_stash () {
>  	git diff $flags $b_commit $w_commit
>  }
>  
> +is_stash_ref() {
> +	revs="$(git rev-parse --revs-only --symbolic --verify --default ${ref_stash} "$@")" &&
> +	test "$ref_stash" = "$(git rev-parse --symbolic-full-name "${revs%@*}")"
> +}
> +
> +assert_stash_ref() {
> +	is_stash_ref "$@" || die "$* is not a stash reference"
> +}