client: Fetch room members before the first encrytped send.

pantalaimon/client.py

@@ -143,6 +143,8 @@ class PanClient(AsyncClient):
         self.task = None
         self.queue = queue
 
+        self.room_members_fetched = defaultdict(bool)
+
         self.send_semaphores = defaultdict(asyncio.Semaphore)
         self.send_decision_queues = dict()  # type: asyncio.Queue
 

pantalaimon/daemon.py

@@ -807,6 +807,17 @@ class ProxyDaemon:
         sem = client.send_semaphores[room_id]
 
         async with sem:
+            # Even though we request the full state we don't receive room
+            # members since we're using lazy loading. The summary is for some
+            # reason empty so nio can't know if room members are missing from
+            # our state. Fetch the room members here instead.
+            if not client.room_members_fetched[room_id]:
+                try:
+                    await client.joined_members(room_id)
+                    client.room_members_fetched[room_id] = True
+                except ClientConnectionError as e:
+                    return web.Response(status=500, text=str(e))
+
             try:
                 return await _send(self.conf.ignore_verification)
             except OlmTrustError as e: