remote: read symbolic refs via `refs_read_symbolic_ref()`

We have two cases in the remote code where we check whether a reference
is symbolic or not, but don't mind in case it doesn't exist or in case
it exists but is a non-symbolic reference. Convert these two callsites
to use the new `refs_read_symbolic_ref()` function, whose intent is to
implement exactly that usecase.

No change in behaviour is expected from this change.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/remote.c

@@ -766,13 +766,15 @@ static int mv(int argc, const char **argv)
 	for_each_ref(read_remote_branches, &rename);
 	for (i = 0; i < remote_branches.nr; i++) {
 		struct string_list_item *item = remote_branches.items + i;
-		int flag = 0;
+		struct strbuf referent = STRBUF_INIT;
 
-		read_ref_full(item->string, RESOLVE_REF_READING, NULL, &flag);
-		if (!(flag & REF_ISSYMREF))
+		if (refs_read_symbolic_ref(get_main_ref_store(the_repository), item->string,
+					   &referent))
 			continue;
 		if (delete_ref(NULL, item->string, NULL, REF_NO_DEREF))
 			die(_("deleting '%s' failed"), item->string);
+
+		strbuf_release(&referent);
 	}
 	for (i = 0; i < remote_branches.nr; i++) {
 		struct string_list_item *item = remote_branches.items + i;

remote.c

@@ -1945,13 +1945,9 @@ const char *branch_get_push(struct branch *branch, struct strbuf *err)
 	return branch->push_tracking_ref;
 }
 
-static int ignore_symref_update(const char *refname)
+static int ignore_symref_update(const char *refname, struct strbuf *scratch)
 {
-	int flag;
-
-	if (!resolve_ref_unsafe(refname, 0, NULL, &flag))
-		return 0; /* non-existing refs are OK */
-	return (flag & REF_ISSYMREF);
+	return !refs_read_symbolic_ref(get_main_ref_store(the_repository), refname, scratch);
 }
 
 /*
@@ -1964,6 +1960,7 @@ static int ignore_symref_update(const char *refname)
 static struct ref *get_expanded_map(const struct ref *remote_refs,
 				    const struct refspec_item *refspec)
 {
+	struct strbuf scratch = STRBUF_INIT;
 	const struct ref *ref;
 	struct ref *ret = NULL;
 	struct ref **tail = &ret;
@@ -1971,11 +1968,13 @@ static struct ref *get_expanded_map(const struct ref *remote_refs,
 	for (ref = remote_refs; ref; ref = ref->next) {
 		char *expn_name = NULL;
 
+		strbuf_reset(&scratch);
+
 		if (strchr(ref->name, '^'))
 			continue; /* a dereference item */
 		if (match_name_with_pattern(refspec->src, ref->name,
 					    refspec->dst, &expn_name) &&
-		    !ignore_symref_update(expn_name)) {
+		    !ignore_symref_update(expn_name, &scratch)) {
 			struct ref *cpy = copy_ref(ref);
 
 			cpy->peer_ref = alloc_ref(expn_name);
@@ -1987,6 +1986,7 @@ static struct ref *get_expanded_map(const struct ref *remote_refs,
 		free(expn_name);
 	}
 
+	strbuf_release(&scratch);
 	return ret;
 }