fix: reasoning parser when request have enable_thinking flag (#8933)

Signed-off-by: Xinyuan Tong <xinyuantong.cs@gmail.com>

python/sglang/srt/entrypoints/openai/serving_chat.py

@@ -840,11 +840,15 @@ class OpenAIServingChat(OpenAIServingBase):
             reasoning_text = None
             reasoning_parser = self.tokenizer_manager.server_args.reasoning_parser
             if reasoning_parser and request.separate_reasoning:
+                is_force_reasoning = (
+                    self.template_manager.force_reasoning
+                    or self._get_enable_thinking_from_request(request)
+                )
                 try:
                     parser = ReasoningParser(
                         model_type=reasoning_parser,
                         stream_reasoning=False,
-                        force_reasoning=self.template_manager.force_reasoning,
+                        force_reasoning=is_force_reasoning,
                     )
                     reasoning_text, text = parser.parse_non_stream(text)
                 except Exception as e:
@@ -1007,10 +1011,14 @@ class OpenAIServingChat(OpenAIServingBase):
     ) -> tuple[Optional[str], str]:
         """Process reasoning content in streaming response"""
         if index not in reasoning_parser_dict:
+            is_force_reasoning = (
+                self.template_manager.force_reasoning
+                or self._get_enable_thinking_from_request(request)
+            )
             reasoning_parser_dict[index] = ReasoningParser(
                 self.tokenizer_manager.server_args.reasoning_parser,
                 request.stream_reasoning,
-                self.template_manager.force_reasoning,
+                is_force_reasoning,
             )
         reasoning_parser = reasoning_parser_dict[index]
         return reasoning_parser.parse_stream_chunk(delta)