[PATCH v2 20/21] refs.c: refactor do_head_ref(... to do_one_head_ref("HEAD", ...

@@ -1721,32 +1721,33 @@ static int do_for_each_ref(struct ref_cache *refs, const char *base,
 	return do_for_each_entry(refs, base, do_one_ref, &data);
 }
 
-static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
+static int do_one_head_ref(const char *ref, const char *submodule,
+		      each_ref_fn fn, void *cb_data)
 {
 	unsigned char sha1[20];
 	int flag;
 
 	if (submodule) {
-		if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
-			return fn("HEAD", sha1, 0, cb_data);
+		if (resolve_gitlink_ref(submodule, ref, sha1) == 0)
+			return fn(ref, sha1, 0, cb_data);
 
 		return 0;
 	}
 
-	if (!read_ref_full("HEAD", sha1, 1, &flag))
-		return fn("HEAD", sha1, flag, cb_data);
+	if (!read_ref_full(ref, sha1, 1, &flag))
+		return fn(ref, sha1, flag, cb_data);
 
 	return 0;
 }
 
 int head_ref(each_ref_fn fn, void *cb_data)
 {
-	return do_head_ref(NULL, fn, cb_data);
+	return do_one_head_ref("HEAD", NULL, fn, cb_data);
 }
 
 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
 {
-	return do_head_ref(submodule, fn, cb_data);
+	return do_one_head_ref("HEAD", submodule, fn, cb_data);
 }
 
 int for_each_ref(each_ref_fn fn, void *cb_data)