files-backend.c: factor out per-worktree code in loose_fill_ref_dir()

This is the first step for further cleaning up and extending this
function.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

refs/files-backend.c

@@ -213,6 +213,33 @@ static void files_ref_path(struct files_ref_store *refs,
 	}
 }
 
+/*
+ * Manually add refs/bisect and refs/worktree, which, being
+ * per-worktree, might not appear in the directory listing for
+ * refs/ in the main repo.
+ */
+static void add_per_worktree_entries_to_dir(struct ref_dir *dir, const char *dirname)
+{
+	int pos;
+
+	if (strcmp(dirname, "refs/"))
+		return;
+
+	pos = search_ref_dir(dir, "refs/bisect/", 12);
+	if (pos < 0) {
+		struct ref_entry *child_entry =
+			create_dir_entry(dir->cache, "refs/bisect/", 12, 1);
+		add_entry_to_dir(dir, child_entry);
+	}
+
+	pos = search_ref_dir(dir, "refs/worktree/", 11);
+	if (pos < 0) {
+		struct ref_entry *child_entry =
+			create_dir_entry(dir->cache, "refs/worktree/", 11, 1);
+		add_entry_to_dir(dir, child_entry);
+	}
+}
+
 /*
  * Read the loose references from the namespace dirname into dir
  * (without recursing).  dirname must end with '/'.  dir must be the
@@ -296,28 +323,7 @@ static void loose_fill_ref_dir(struct ref_store *ref_store,
 	strbuf_release(&path);
 	closedir(d);
 
-	/*
-	 * Manually add refs/bisect and refs/worktree, which, being
-	 * per-worktree, might not appear in the directory listing for
-	 * refs/ in the main repo.
-	 */
-	if (!strcmp(dirname, "refs/")) {
-		int pos = search_ref_dir(dir, "refs/bisect/", 12);
-
-		if (pos < 0) {
-			struct ref_entry *child_entry = create_dir_entry(
-					dir->cache, "refs/bisect/", 12, 1);
-			add_entry_to_dir(dir, child_entry);
-		}
-
-		pos = search_ref_dir(dir, "refs/worktree/", 11);
-
-		if (pos < 0) {
-			struct ref_entry *child_entry = create_dir_entry(
-					dir->cache, "refs/worktree/", 11, 1);
-			add_entry_to_dir(dir, child_entry);
-		}
-	}
+	add_per_worktree_entries_to_dir(dir, dirname);
 }
 
 static struct ref_cache *get_loose_ref_cache(struct files_ref_store *refs)