Fix type of _protocol field

Author: PierreF

src/paho/mqtt/client.py

@@ -732,7 +732,7 @@ def __init__(
         client_id: str | None = "",
         clean_session: bool | None = None,
         userdata: Any = None,
-        protocol: int = MQTTv311,
+        protocol: MQTTProtocolVersion = MQTTv311,
         transport: Literal["tcp", "websockets"] = "tcp",
         reconnect_on_failure: bool = True,
         manual_ack: bool = False,
@@ -3462,7 +3462,7 @@ def _send_simple_command(self, command: int) -> MQTTErrorCode:
         return self._packet_queue(command, packet, 0, 0)
 
     def _send_connect(self, keepalive: int) -> MQTTErrorCode:
-        proto_ver = self._protocol
+        proto_ver = int(self._protocol)
         # hard-coded UTF-8 encoded string
         protocol = b"MQTT" if proto_ver >= MQTTv311 else b"MQIsdp"
 

src/paho/mqtt/publish.py

@@ -24,7 +24,7 @@
 from collections.abc import Iterable
 from typing import TYPE_CHECKING, Any, List, Tuple, Union
 
-from paho.mqtt.enums import CallbackAPIVersion
+from paho.mqtt.enums import CallbackAPIVersion, MQTTProtocolVersion
 from paho.mqtt.properties import Properties
 from paho.mqtt.reasoncodes import ReasonCode
 
@@ -112,7 +112,7 @@ def multiple(
     will: MessageDict | None = None,
     auth: AuthParameter | None = None,
     tls: TLSParameter | None = None,
-    protocol: int = paho.MQTTv311,
+    protocol: MQTTProtocolVersion = paho.MQTTv311,
     transport: Literal["tcp", "websockets"] = "tcp",
     proxy_args: Any | None = None,
 ) -> None:
@@ -240,7 +240,7 @@ def single(
     will: MessageDict | None = None,
     auth: AuthParameter | None = None,
     tls: TLSParameter | None = None,
-    protocol: int = paho.MQTTv311,
+    protocol: MQTTProtocolVersion = paho.MQTTv311,
     transport: Literal["tcp", "websockets"] = "tcp",
     proxy_args: Any | None = None,
 ) -> None: