Show correct error when logging out and access token is missing

changelog.d/5256.bugfix

@@ -0,0 +1 @@
+Show the correct error when logging out and access token is missing.

synapse/rest/client/v1/logout.py

@@ -17,8 +17,6 @@
 
 from twisted.internet import defer
 
-from synapse.api.errors import AuthError
-
 from .base import ClientV1RestServlet, client_path_patterns
 
 logger = logging.getLogger(__name__)
@@ -38,23 +36,16 @@ def on_OPTIONS(self, request):
 
     @defer.inlineCallbacks
     def on_POST(self, request):
-        try:
-            requester = yield self.auth.get_user_by_req(request)
-        except AuthError:
-            # this implies the access token has already been deleted.
-            defer.returnValue((401, {
-                "errcode": "M_UNKNOWN_TOKEN",
-                "error": "Access Token unknown or expired"
-            }))
+        requester = yield self.auth.get_user_by_req(request)
+
+        if requester.device_id is None:
+            # the acccess token wasn't associated with a device.
+            # Just delete the access token
+            access_token = self._auth.get_access_token_from_request(request)
+            yield self._auth_handler.delete_access_token(access_token)
         else:
-            if requester.device_id is None:
-                # the acccess token wasn't associated with a device.
-                # Just delete the access token
-                access_token = self._auth.get_access_token_from_request(request)
-                yield self._auth_handler.delete_access_token(access_token)
-            else:
-                yield self._device_handler.delete_device(
-                    requester.user.to_string(), requester.device_id)
+            yield self._device_handler.delete_device(
+                requester.user.to_string(), requester.device_id)
 
         defer.returnValue((200, {}))