Restore fallback when FastPath.root is empty. Fixes #353.

Author: jaraco

importlib_metadata/__init__.py

@@ -447,7 +447,7 @@ def joinpath(self, child):
 
     def children(self):
         with suppress(Exception):
-            return os.listdir(self.root or '')
+            return os.listdir(self.root or '.')
         with suppress(Exception):
             return self.zip_children()
         return []