From 215bf150a61ed3aafba35df65c95f63c82cc94b2 Mon Sep 17 00:00:00 2001
From: Florian Greinacher <florian.greinacher@siemens.com>
Date: Wed, 26 Feb 2025 12:06:21 +0100
Subject: [PATCH] [Bugfix] Handle None parameters in Mistral function calls.
 (#13786)

---
 tests/tokenization/test_mistral_tokenizer.py  | 35 ++++++++++++++++++-
 vllm/transformers_utils/tokenizers/mistral.py |  3 +-
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/tests/tokenization/test_mistral_tokenizer.py b/tests/tokenization/test_mistral_tokenizer.py
index 03e1f1fa..f1c88028 100644
--- a/tests/tokenization/test_mistral_tokenizer.py
+++ b/tests/tokenization/test_mistral_tokenizer.py
@@ -41,7 +41,40 @@ from vllm.transformers_utils.tokenizers.mistral import (
                 )
             ],
         ),
-    )],
+    ),
+     (
+         {
+             "messages":
+             [{
+                 "role": "user",
+                 "content": "What is the current local date and time?",
+             }],
+             "tools": [{
+                 "type": "function",
+                 "function": {
+                     "description": "Fetch the current local date and time.",
+                     "name": "get_current_time",
+                     "parameters": None,
+                 },
+             }],
+         },
+         ChatCompletionRequest(
+             messages=[
+                 UserMessage(
+                     content="What is the current local date and time?")
+             ],
+             tools=[
+                 Tool(
+                     type="function",
+                     function=Function(
+                         name="get_current_time",
+                         description="Fetch the current local date and time.",
+                         parameters={},
+                     ),
+                 )
+             ],
+         ),
+     )],
 )
 def test_make_mistral_chat_completion_request(openai_request,
                                               expected_mistral_request):
diff --git a/vllm/transformers_utils/tokenizers/mistral.py b/vllm/transformers_utils/tokenizers/mistral.py
index 4e76f2dc..801597bd 100644
--- a/vllm/transformers_utils/tokenizers/mistral.py
+++ b/vllm/transformers_utils/tokenizers/mistral.py
@@ -164,7 +164,8 @@ def make_mistral_chat_completion_request(
                 tool["function"] for tool in tools
                 if tool["type"] == "function"
         ]:
-            function.setdefault("parameters", {})
+            if function.get("parameters") is None:
+                function["parameters"] = {}
 
     from mistral_common.protocol.instruct.request import ChatCompletionRequest
     return ChatCompletionRequest(messages=messages,