From 7008ec077b1b058953d55a7a33749a01f69d4a3f Mon Sep 17 00:00:00 2001
From: Dirk Alders <dirk@mount-mockery.de>
Date: Tue, 22 Jul 2025 20:23:20 +0200
Subject: [PATCH] fix for exception, when sending mqtt messages without topic

---
 mqtt_sniffer.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mqtt_sniffer.py b/mqtt_sniffer.py
index 6a4a54d..a52d865 100644
--- a/mqtt_sniffer.py
+++ b/mqtt_sniffer.py
@@ -130,7 +130,10 @@ class MqttSniffer(App):
         """Event handler called when a button is pressed."""
         if event.button.id == "send_button":
             if self.mqtt is not None:
-                self.mqtt.send(self.send_topic, self.send_payload)
+                if len(self.send_topic) > 0:
+                    self.mqtt.send(self.send_topic, self.send_payload)
+                else:
+                    logger.warning("Can't send mqtt message with empty topic. topic=%s; payload=%s", repr(self.send_topic), repr(self.send_payload))
 
 
 if __name__ == "__main__":