Move deprecation error back to _handle_request().

aiohttp/web_protocol.py

@@ -422,7 +422,10 @@ async def _handle_request(
                 resp = await self._request_handler(request)
             finally:
                 self._current_request = None
-        except (HTTPException, asyncio.CancelledError):
+        except HTTPException as exc:
+            resp = exc
+            reset = await self.finish_response(request, resp, start_time)
+        except asyncio.CancelledError:
             raise
         except asyncio.TimeoutError as exc:
             self.log_debug("Request handler timed out.", exc_info=exc)
@@ -432,6 +435,15 @@ async def _handle_request(
             resp = self.handle_error(request, 500, exc)
             reset = await self.finish_response(request, resp, start_time)
         else:
+            # Deprecation warning (See #2415)
+            if getattr(resp, "__http_exception__", False):
+                warnings.warn(
+                    "returning HTTPException object is deprecated "
+                    "(#2415) and will be removed, "
+                    "please raise the exception instead",
+                    DeprecationWarning,
+                )
+
             reset = await self.finish_response(request, resp, start_time)
 
         return resp, reset
@@ -478,21 +490,9 @@ async def start(self) -> None:
                 task = self._loop.create_task(self._handle_request(request, start))
                 try:
                     resp, reset = await task
-                except HTTPException as exc:
-                    resp = exc
-                    reset = await self.finish_response(request, resp, start)
                 except (asyncio.CancelledError, ConnectionError):
                     self.log_debug("Ignored premature client disconnection")
                     break
-                else:
-                    # Deprecation warning (See #2415)
-                    if getattr(resp, "__http_exception__", False):
-                        warnings.warn(
-                            "returning HTTPException object is deprecated "
-                            "(#2415) and will be removed, "
-                            "please raise the exception instead",
-                            DeprecationWarning,
-                        )
 
                 # Drop the processed task from asyncio.Task.all_tasks() early
                 del task