Fix AttributeError: 'NoneType' object has no attribute 'name' (#3127)

There is a bug related to the interplay between the society of mind agent and the FileLogger, probably somewhere around https://github.com/microsoft/autogen/blob/main/autogen/agentchat/contrib/society_of_mind_agent.py#L181, which causes an empty name property to be sent. The FileLogger should gracefully handle this circumstance and not return an error to the function caller.

Co-authored-by: Chi Wang <[email protected]>
Co-authored-by: Jack Gerrits <[email protected]>

autogen/logger/file_logger.py

@@ -90,7 +90,7 @@ def log_chat_completion(
         thread_id = threading.get_ident()
         source_name = None
         if isinstance(source, str):
-            source_name = source
+            source_name = getattr(source, "name", "unknown")
         else:
             source_name = source.name
         try: