fetch: refactor to make function args narrower

Refactor find_non_local_tags and get_ref_map to only take the
information they need instead of the entire transport struct. Besides
improving code clarity, this also improves their flexibility, allowing
for a different set of refs to be used instead of relying on the ones
stored in the transport struct.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fetch.c

@@ -254,7 +254,7 @@ static int will_fetch(struct ref **head, const unsigned char *sha1)
 	return 0;
 }
 
-static void find_non_local_tags(struct transport *transport,
+static void find_non_local_tags(const struct ref *refs,
 				struct ref **head,
 				struct ref ***tail)
 {
@@ -264,7 +264,7 @@ static void find_non_local_tags(struct transport *transport,
 	struct string_list_item *item = NULL;
 
 	for_each_ref(add_existing, &existing_refs);
-	for (ref = transport_get_remote_refs(transport, NULL); ref; ref = ref->next) {
+	for (ref = refs; ref; ref = ref->next) {
 		if (!starts_with(ref->name, "refs/tags/"))
 			continue;
 
@@ -338,7 +338,8 @@ static void find_non_local_tags(struct transport *transport,
 	string_list_clear(&remote_refs, 0);
 }
 
-static struct ref *get_ref_map(struct transport *transport,
+static struct ref *get_ref_map(struct remote *remote,
+			       const struct ref *remote_refs,
 			       struct refspec *rs,
 			       int tags, int *autotags)
 {
@@ -346,27 +347,11 @@ static struct ref *get_ref_map(struct transport *transport,
 	struct ref *rm;
 	struct ref *ref_map = NULL;
 	struct ref **tail = &ref_map;
-	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 
 	/* opportunistically-updated references: */
 	struct ref *orefs = NULL, **oref_tail = &orefs;
 
 	struct string_list existing_refs = STRING_LIST_INIT_DUP;
-	const struct ref *remote_refs;
-
-	if (rs->nr)
-		refspec_ref_prefixes(rs, &ref_prefixes);
-	else if (transport->remote && transport->remote->fetch.nr)
-		refspec_ref_prefixes(&transport->remote->fetch, &ref_prefixes);
-
-	if (ref_prefixes.argc &&
-	    (tags == TAGS_SET || (tags == TAGS_DEFAULT && !rs->nr))) {
-		argv_array_push(&ref_prefixes, "refs/tags/");
-	}
-
-	remote_refs = transport_get_remote_refs(transport, &ref_prefixes);
-
-	argv_array_clear(&ref_prefixes);
 
 	if (rs->nr) {
 		struct refspec *fetch_refspec;
@@ -403,7 +388,7 @@ static struct ref *get_ref_map(struct transport *transport,
 		if (refmap.nr)
 			fetch_refspec = &refmap;
 		else
-			fetch_refspec = &transport->remote->fetch;
+			fetch_refspec = &remote->fetch;
 
 		for (i = 0; i < fetch_refspec->nr; i++)
 			get_fetch_map(ref_map, &fetch_refspec->items[i], &oref_tail, 1);
@@ -411,7 +396,6 @@ static struct ref *get_ref_map(struct transport *transport,
 		die("--refmap option is only meaningful with command-line refspec(s).");
 	} else {
 		/* Use the defaults */
-		struct remote *remote = transport->remote;
 		struct branch *branch = branch_get(NULL);
 		int has_merge = branch_has_merge_config(branch);
 		if (remote &&
@@ -450,7 +434,7 @@ static struct ref *get_ref_map(struct transport *transport,
 		/* also fetch all tags */
 		get_fetch_map(remote_refs, tag_refspec, &tail, 0);
 	else if (tags == TAGS_DEFAULT && *autotags)
-		find_non_local_tags(transport, &ref_map, &tail);
+		find_non_local_tags(remote_refs, &ref_map, &tail);
 
 	/* Now append any refs to be updated opportunistically: */
 	*tail = orefs;
@@ -1143,6 +1127,8 @@ static int do_fetch(struct transport *transport,
 	struct ref *ref_map;
 	int autotags = (transport->remote->fetch_tags == 1);
 	int retcode = 0;
+	const struct ref *remote_refs;
+	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
 
 	if (tags == TAGS_DEFAULT) {
 		if (transport->remote->fetch_tags == 2)
@@ -1158,7 +1144,21 @@ static int do_fetch(struct transport *transport,
 			goto cleanup;
 	}
 
-	ref_map = get_ref_map(transport, rs, tags, &autotags);
+	if (rs->nr)
+		refspec_ref_prefixes(rs, &ref_prefixes);
+	else if (transport->remote && transport->remote->fetch.nr)
+		refspec_ref_prefixes(&transport->remote->fetch, &ref_prefixes);
+
+	if (ref_prefixes.argc &&
+	    (tags == TAGS_SET || (tags == TAGS_DEFAULT && !rs->nr))) {
+		argv_array_push(&ref_prefixes, "refs/tags/");
+	}
+
+	remote_refs = transport_get_remote_refs(transport, &ref_prefixes);
+	argv_array_clear(&ref_prefixes);
+
+	ref_map = get_ref_map(transport->remote, remote_refs, rs,
+			      tags, &autotags);
 	if (!update_head_ok)
 		check_not_current_branch(ref_map);
 
@@ -1190,7 +1190,7 @@ static int do_fetch(struct transport *transport,
 	if (tags == TAGS_DEFAULT && autotags) {
 		struct ref **tail = &ref_map;
 		ref_map = NULL;
-		find_non_local_tags(transport, &ref_map, &tail);
+		find_non_local_tags(remote_refs, &ref_map, &tail);
 		if (ref_map)
 			backfill_tags(transport, ref_map);
 		free_refs(ref_map);