config: T5228: fix key shift in merge_defaults

python/vyos/xml_ref/definition.py

@@ -213,19 +213,20 @@ def merge_defaults(self, path: list, conf: dict) -> dict:
 
         This merges non-recursive defaults relative to the config dict.
         """
-        if path[-1] in list(conf):
-            config = conf[path[-1]]
-            if not isinstance(config, dict):
+        if not path:
+            shift = False
+        elif path[-1] in list(conf):
+            conf = conf[path[-1]]
+            if not isinstance(conf, dict):
                 raise TypeError('conf at path is not of type dict')
             shift = False
         else:
-            config = conf
             shift = True
 
-        if not self._well_defined(path, config):
+        if not self._well_defined(path, conf):
             print('path to config dict does not define config paths; conf returned unchanged')
             return conf
 
-        d = self.relative_defaults(path, conf=config, get_first_key=shift)
+        d = self.relative_defaults(path, conf=conf, get_first_key=shift)
         d = dict_merge(d, conf)
         return d