Fix: mess count might be 0

Author: bnmnetp

controllers/peer.py

@@ -274,7 +274,12 @@ def num_answers():
         & (db.mchoice_answers.timestamp > parse(request.vars.start_time))
     ).count(distinct=db.mchoice_answers.sid)
     r = redis.from_url(os.environ.get("REDIS_URI", "redis://redis:6379/0"))
-    mess_count = int(r.hget(f"{auth.user.course_name}_state", "mess_count"))
+    res = r.hget(f"{auth.user.course_name}_state", "mess_count")
+    if res is not None:
+        mess_count = int(res)
+    else:
+        mess_count = 0
+
     return json.dumps({"count": acount, "mess_count": mess_count})