pack-objects: simplify --filter handling

pack-objects uses OPT_PARSE_LIST_OBJECTS_FILTER_INIT() to initialize the
a rev_info struct lazily before populating its filter member using the
--filter option values.  It tracks whether the initialization is needed
using the .have_revs member of the callback data.

There is a better way: Use a stand-alone list_objects_filter_options
struct and build a rev_info struct with its .filter member after option
parsing.  This allows using the simpler OPT_PARSE_LIST_OBJECTS_FILTER()
and getting rid of the extra callback mechanism.

Even simpler would be using a struct rev_info as before 5cb2827
(pack-objects: lazily set up "struct rev_info", don't leak, 2022-03-28),
but that would expose a memory leak caused by repo_init_revisions()
followed by release_revisions() without a setup_revisions() call in
between.

Using list_objects_filter_options also allows pushing the rev_info
struct into get_object_list(), where it arguably belongs. Either way,
this is all left for later.

Helped-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: René Scharfe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

builtin/pack-objects.c

@@ -4149,22 +4149,6 @@ static int option_parse_cruft_expiration(const struct option *opt,
 	return 0;
 }
 
-struct po_filter_data {
-	unsigned have_revs:1;
-	struct rev_info revs;
-};
-
-static struct list_objects_filter_options *po_filter_revs_init(void *value)
-{
-	struct po_filter_data *data = value;
-
-	if (!data->have_revs)
-		repo_init_revisions(the_repository, &data->revs, NULL);
-	data->have_revs = 1;
-
-	return &data->revs.filter;
-}
-
 int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 {
 	int use_internal_rev_list = 0;
@@ -4175,7 +4159,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	int rev_list_index = 0;
 	int stdin_packs = 0;
 	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
-	struct po_filter_data pfd = { .have_revs = 0 };
+	struct list_objects_filter_options filter_options =
+		LIST_OBJECTS_FILTER_INIT;
 
 	struct option pack_objects_options[] = {
 		OPT_SET_INT('q', "quiet", &progress,
@@ -4266,7 +4251,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			      &write_bitmap_index,
 			      N_("write a bitmap index if possible"),
 			      WRITE_BITMAP_QUIET, PARSE_OPT_HIDDEN),
-		OPT_PARSE_LIST_OBJECTS_FILTER_INIT(&pfd, po_filter_revs_init),
+		OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
 		OPT_CALLBACK_F(0, "missing", NULL, N_("action"),
 		  N_("handling for missing objects"), PARSE_OPT_NONEG,
 		  option_parse_missing_action),
@@ -4386,7 +4371,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (!rev_list_all || !rev_list_reflog || !rev_list_index)
 		unpack_unreachable_expiration = 0;
 
-	if (pfd.have_revs && pfd.revs.filter.choice) {
+	if (filter_options.choice) {
 		if (!pack_to_stdout)
 			die(_("cannot use --filter without --stdout"));
 		if (stdin_packs)
@@ -4473,13 +4458,11 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		read_cruft_objects();
 	} else if (!use_internal_rev_list) {
 		read_object_list_from_stdin();
-	} else if (pfd.have_revs) {
-		get_object_list(&pfd.revs, rp.nr, rp.v);
-		release_revisions(&pfd.revs);
 	} else {
 		struct rev_info revs;
 
 		repo_init_revisions(the_repository, &revs, NULL);
+		list_objects_filter_copy(&revs.filter, &filter_options);
 		get_object_list(&revs, rp.nr, rp.v);
 		release_revisions(&revs);
 	}
@@ -4514,6 +4497,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 			   reuse_packfile_objects);
 
 cleanup:
+	list_objects_filter_release(&filter_options);
 	strvec_clear(&rp);
 
 	return 0;