- Raise error on `publish.multiple()` when `msgs` is an empty list.

Closes #684. Thanks to Jinyu Liu.

ChangeLog.txt

@@ -4,6 +4,7 @@ v1.6.2 - 2021-xx-xx
 - Fix handling of MQTT v5.0 PUBREL messages with remaining length not equal to
   2. Closes #696.
 - Raise error on `subscribe()` when `topic` is an empty list. Closes #690.
+- Raise error on `publish.multiple()` when `msgs` is an empty list. Closes #684.
 
 
 v1.6.1 - 2021-10-21

src/paho/mqtt/publish.py

@@ -135,6 +135,8 @@ def multiple(msgs, hostname="localhost", port=1883, client_id="", keepalive=60,
 
     if not isinstance(msgs, Iterable):
         raise TypeError('msgs must be an iterable')
+    if len(msgs) == 0:
+        raise ValueError('msgs is empty')
 
 
     client = paho.Client(client_id=client_id, userdata=collections.deque(msgs),