add check for messages

Author: kxz2002

fastdeploy/entrypoints/openai/protocol.py

@@ -671,7 +671,7 @@ def to_dict_for_infer(self, request_id=None):
         if request_id is not None:
             req_dict["request_id"] = request_id
 
-        if "prompt_token_ids" not in req_dict:
+        if "prompt_token_ids" not in req_dict or not req_dict["prompt_token_ids"]:
             # If disable_chat_template is set, then the first message in messages will be used as the prompt.
             assert (
                 len(req_dict["messages"]) > 0