fix: "PHP Notice: Uninitialized string offset: 0 in ..."

libs/Tree/Directory.php

@@ -32,6 +32,8 @@ class Directory extends Entry implements \ArrayAccess, \IteratorAggregate
                 continue;
             }
 
+            if (!$name) continue;
+
             if ($name[0] == '-') {
                 if (is_numeric($name[1])) {
                     $exploded = explode('_', $name);