🐛 Fix empty reponse body when default status_code is empty but the a Response parameter with response.status_code is set

fastapi/routing.py

@@ -258,7 +258,7 @@ async def app(request: Request) -> Response:
                 is_coroutine=is_coroutine,
             )
             response = actual_response_class(content, **response_args)
-            if not is_body_allowed_for_status_code(status_code):
+            if not is_body_allowed_for_status_code(response.status_code):
                 response.body = b""
             response.headers.raw.extend(sub_response.headers.raw)
             return response

tests/test_reponse_set_reponse_code.py

@@ -0,0 +1,31 @@
+from fastapi import FastAPI, Response
+from fastapi.params import Path
+from fastapi.testclient import TestClient
+
+msg = {"msg": "Status overwritten"}
+
+app = FastAPI()
+
+
+@app.delete(
+    "/{id}",
+    responses={
+        204: {"model": None, "description": "No Content"},
+    },
+    status_code=204,
+)
+async def delete_deployment(
+    id: str = Path(None),
+    response: Response = None,
+) -> None:
+    response.status_code = 400
+    return msg
+
+
+client = TestClient(app)
+
+
+def test_dependency_set_status_code():
+    response = client.delete("/1")
+    assert response.status_code == 400 and response.content
+    assert response.json() == msg