ref-filter.c: really don't sort when using --no-sort

When '--no-sort' is passed to 'for-each-ref', 'tag', and 'branch', the
printed refs are still sorted by ascending refname. Change the handling of
sort options in these commands so that '--no-sort' to truly disables
sorting.

'--no-sort' does not disable sorting in these commands is because their
option parsing does not distinguish between "the absence of '--sort'"
(and/or values for tag.sort & branch.sort) and '--no-sort'. Both result in
an empty 'sorting_options' string list, which is parsed by
'ref_sorting_options()' to create the 'struct ref_sorting *' for the
command. If the string list is empty, 'ref_sorting_options()' interprets
that as "the absence of '--sort'" and returns the default ref sorting
structure (equivalent to "refname" sort).

To handle '--no-sort' properly while preserving the "refname" sort in the
"absence of --sort'" case, first explicitly add "refname" to the string list
*before* parsing options. This alone doesn't actually change any behavior,
since 'compare_refs()' already falls back on comparing refnames if two refs
are equal w.r.t all other sort keys.

Now that the string list is populated by default, '--no-sort' is the only
way to empty the 'sorting_options' string list. Update
'ref_sorting_options()' to return a NULL 'struct ref_sorting *' if the
string list is empty, and add a condition to 'ref_array_sort()' to skip the
sort altogether if the sort structure is NULL. Note that other functions
using 'struct ref_sorting *' do not need any changes because they already
ignore NULL values.

Finally, remove the condition around sorting in 'ls-remote', since it's no
longer necessary. Unlike 'for-each-ref' et. al., it does *not* do any
sorting by default. This default is preserved by simply leaving its sort key
string list empty before parsing options; if no additional sort keys are
set, 'struct ref_sorting *' is NULL and sorting is skipped.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 16 deletions

diff --git a/ref-filter.c b/ref-filter.c
index 9dbc4f7..f65551d 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -3058,7 +3058,8 @@ void ref_sorting_set_sort_flags_all(struct ref_sorting *sorting,
 
 void ref_array_sort(struct ref_sorting *sorting, struct ref_array *array)
 {
-	QSORT_S(array->items, array->nr, compare_refs, sorting);
+	if (sorting)
+		QSORT_S(array->items, array->nr, compare_refs, sorting);
 }
 
 static void append_literal(const char *cp, const char *ep, struct ref_formatting_state *state)
@@ -3164,18 +3165,6 @@ static int parse_sorting_atom(const char *atom)
 	return res;
 }
 
-/*  If no sorting option is given, use refname to sort as default */
-static struct ref_sorting *ref_default_sorting(void)
-{
-	static const char cstr_name[] = "refname";
-
-	struct ref_sorting *sorting = xcalloc(1, sizeof(*sorting));
-
-	sorting->next = NULL;
-	sorting->atom = parse_sorting_atom(cstr_name);
-	return sorting;
-}
-
 static void parse_ref_sorting(struct ref_sorting **sorting_tail, const char *arg)
 {
 	struct ref_sorting *s;
@@ -3199,9 +3188,7 @@ struct ref_sorting *ref_sorting_options(struct string_list *options)
 	struct string_list_item *item;
 	struct ref_sorting *sorting = NULL, **tail = &sorting;
 
-	if (!options->nr) {
-		sorting = ref_default_sorting();
-	} else {
+	if (options->nr) {
 		for_each_string_list_item(item, options)
 			parse_ref_sorting(tail, item->string);
 	}