ref-filter: populate symref from iterator

With a previous commit, the reference the symbolic ref points is saved
in the ref iterator records. Instead of making a separate call to
resolve_refdup() each time, we can just populate the ref_array_item with
the value from the iterator.

Signed-off-by: John Cai <johncai86@gmail.com>

ref-filter.c

@@ -2781,7 +2781,7 @@ static int filter_ref_kind(struct ref_filter *filter, const char *refname)
 	return ref_kind_from_refname(refname);
 }
 
-static struct ref_array_item *apply_ref_filter(const char *refname, const struct object_id *oid,
+static struct ref_array_item *apply_ref_filter(const char *refname, const char *referent, const struct object_id *oid,
 			    int flag, struct ref_filter *filter)
 {
 	struct ref_array_item *ref;
@@ -2850,6 +2850,8 @@ static struct ref_array_item *apply_ref_filter(const char *refname, const struct
 	ref->commit = commit;
 	ref->flag = flag;
 	ref->kind = kind;
+	if (referent)
+		ref->symref = xstrdup(referent);
 
 	return ref;
 }
@@ -2863,12 +2865,12 @@ struct ref_filter_cbdata {
  * A call-back given to for_each_ref().  Filter refs and keep them for
  * later object processing.
  */
-static int filter_one(const char *refname, const char *referent UNUSED, const struct object_id *oid, int flag, void *cb_data)
+static int filter_one(const char *refname, const char *referent, const struct object_id *oid, int flag, void *cb_data)
 {
 	struct ref_filter_cbdata *ref_cbdata = cb_data;
 	struct ref_array_item *ref;
 
-	ref = apply_ref_filter(refname, oid, flag, ref_cbdata->filter);
+	ref = apply_ref_filter(refname, referent, oid, flag, ref_cbdata->filter);
 	if (ref)
 		ref_array_append(ref_cbdata->array, ref);
 
@@ -2898,13 +2900,13 @@ struct ref_filter_and_format_cbdata {
 	} internal;
 };
 
-static int filter_and_format_one(const char *refname, const char *referent UNUSED, const struct object_id *oid, int flag, void *cb_data)
+static int filter_and_format_one(const char *refname, const char *referent, const struct object_id *oid, int flag, void *cb_data)
 {
 	struct ref_filter_and_format_cbdata *ref_cbdata = cb_data;
 	struct ref_array_item *ref;
 	struct strbuf output = STRBUF_INIT, err = STRBUF_INIT;
 
-	ref = apply_ref_filter(refname, oid, flag, ref_cbdata->filter);
+	ref = apply_ref_filter(refname, referent, oid, flag, ref_cbdata->filter);
 	if (!ref)
 		return 0;