client: Error out gracefully if we get an invalid limit.

pantalaimon/client.py

@@ -103,6 +103,8 @@ class UnknownRoomError(Exception):
 class InvalidOrderByError(Exception):
     pass
 
+class InvalidLimit(Exception):
+    pass
 
 class PanClient(AsyncClient):
     """A wrapper class around a nio AsyncClient extending its functionality."""
@@ -717,6 +719,10 @@ class PanClient(AsyncClient):
         term = search_terms["search_term"]
         search_filter = search_terms["filter"]
         limit = search_filter.get("limit", 10)
+
+        if limit <= 0:
+            raise InvalidLimit(f"The limit must be strictly greater than 0.")
+
         order_by = search_terms.get("order_by")
 
         if order_by not in ["rank", "recent"]:

pantalaimon/daemon.py

@@ -28,7 +28,8 @@ from multidict import CIMultiDict
 from nio import (Api, EncryptionError, LoginResponse, OlmTrustError,
                  SendRetryError)
 
-from pantalaimon.client import InvalidOrderByError, PanClient, UnknownRoomError
+from pantalaimon.client import (InvalidOrderByError, PanClient,
+                                UnknownRoomError, InvalidLimit)
 from pantalaimon.log import logger
 from pantalaimon.store import ClientInfo, PanStore
 from pantalaimon.thread_messages import (AcceptSasMessage, CancelSasMessage,
@@ -942,7 +943,7 @@ class ProxyDaemon:
                 },
                 status=400,
             )
-        except InvalidOrderByError as e:
+        except (InvalidOrderByError, InvalidLimit) as e:
             return web.json_response(
                 {
                     "errcode": "M_INVALID_PARAM",