Fix possible thread locking situation.

diff --git a/lib/python/mosquitto.py b/lib/python/mosquitto.py
index c00ac08659c1242ebb3ba1e9f7fe578cc5d9d445..86f6ce97e67a546df3612164bf81fb9282d514f3 100755 (executable)
--- a/lib/python/mosquitto.py
+++ b/lib/python/mosquitto.py
@@ -1511,7 +1511,7 @@ class Mosquitto:
             self._current_out_packet_mutex.release()
         self._out_packet_mutex.release()
 
-        if not self._in_callback:
+        if not self._in_callback and self._thread == None:
             return self.loop_write()
         else:
             return MOSQ_ERR_SUCCESS