REvert loop misc but make it only disconnect on _last_msg_in, not _ping_t

Author: JamesParrott

src/paho/mqtt/client.py

@@ -2153,30 +2153,27 @@ def loop_misc(self) -> MQTTErrorCode:
         now = time_func()
         self._check_keepalive()
 
-        if self._ping_t == 0:
-            return MQTTErrorCode.MQTT_ERR_SUCCESS
-        if now - self._ping_t < self._keepalive:
-            return MQTTErrorCode.MQTT_ERR_SUCCESS
-        if now - self._last_msg_in < self._keepalive:
-            return MQTTErrorCode.MQTT_ERR_SUCCESS
+        if self._ping_t > 0 and now - self._last_msg_in >= self._keepalive:
+            # client->ping_t != 0 means we are waiting for a pingresp.
+            # This hasn't happened in the keepalive time so we should disconnect.
+            self._sock_close()
 
-        # client->ping_t != 0 means we are waiting for a pingresp.
-        # This hasn't happened in the keepalive time so we should disconnect.
-        self._sock_close()
+            if self._state in (_ConnectionState.MQTT_CS_DISCONNECTING, _ConnectionState.MQTT_CS_DISCONNECTED):
+                self._state = _ConnectionState.MQTT_CS_DISCONNECTED
+                rc = MQTTErrorCode.MQTT_ERR_SUCCESS
+            else:
+                self._state = _ConnectionState.MQTT_CS_CONNECTION_LOST
+                rc = MQTTErrorCode.MQTT_ERR_KEEPALIVE
 
-        if self._state in (_ConnectionState.MQTT_CS_DISCONNECTING, _ConnectionState.MQTT_CS_DISCONNECTED):
-            self._state = _ConnectionState.MQTT_CS_DISCONNECTED
-            rc = MQTTErrorCode.MQTT_ERR_SUCCESS
-        else:
-            self._state = _ConnectionState.MQTT_CS_CONNECTION_LOST
-            rc = MQTTErrorCode.MQTT_ERR_KEEPALIVE
+            self._do_on_disconnect(
+                packet_from_broker=False,
+                v1_rc=rc,
+            )
 
-        self._do_on_disconnect(
-            packet_from_broker=False,
-            v1_rc=rc,
-        )
+            return MQTTErrorCode.MQTT_ERR_CONN_LOST
+
+        return MQTTErrorCode.MQTT_ERR_SUCCESS
 
-        return MQTTErrorCode.MQTT_ERR_CONN_LOST
 
 
     def max_inflight_messages_set(self, inflight: int) -> None: