Re: [PATCH v2] ref-filter: format iteratively with lexicographic refname sorting

> [snip]
>
>  ref-filter.c | 28 +++++++++++++++++++++-------
>  1 file changed, 21 insertions(+), 7 deletions(-)
>
> diff --git a/ref-filter.c b/ref-filter.c
> index dd195007ce1..424a9cb50ae 100644
> --- a/ref-filter.c
> +++ b/ref-filter.c
> @@ -3244,10 +3244,31 @@ int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int
>  	return ret;
>  }
>  
> +struct ref_sorting {
> +	struct ref_sorting *next;
> +	int atom; /* index into used_atom array (internal) */
> +	enum ref_sorting_order sort_flags;
> +};
> +
>  static inline int can_do_iterative_format(struct ref_filter *filter,
>  					  struct ref_sorting *sorting,
>  					  struct ref_format *format)
>  {
> +	/*
> +	 * Reference backends sort patterns lexicographically by refname, so if
> +	 * the sorting options ask for exactly that we are able to do iterative
> +	 * formatting.
> +	 *
> +	 * Note that we do not have to worry about multiple name patterns,
> +	 * either. Those get sorted and deduplicated eventually in
> +	 * `refs_for_each_fullref_in_prefixes()`, so we return names in the
> +	 * correct ordering here, too.
> +	 */
> +	if (sorting && (sorting->next ||
> +			sorting->sort_flags ||
> +			used_atom[sorting->atom].atom_type != ATOM_REFNAME))
> +		return 0;
> +
>  	/*
>  	 * Filtering & formatting results within a single ref iteration
>  	 * callback is not compatible with options that require
> @@ -3258,7 +3279,6 @@ static inline int can_do_iterative_format(struct ref_filter *filter,
>  	 */
>  	return !(filter->reachable_from ||
>  		 filter->unreachable_from ||
> -		 sorting ||