fix: always set `doctype` from `options` for child

frappe/model/base_document.py

@@ -221,10 +221,9 @@ class BaseDocument(object):
 		if not self.doctype:
 			return value
 		if not isinstance(value, BaseDocument):
-			if "doctype" not in value or value['doctype'] is None:
-				value["doctype"] = self.get_table_field_doctype(key)
-				if not value["doctype"]:
-					raise AttributeError(key)
+			value["doctype"] = self.get_table_field_doctype(key)
+			if not value["doctype"]:
+				raise AttributeError(key)
 
 			value = get_controller(value["doctype"])(value)
 			value.init_valid_columns()