From 1c1b39ea2907a8619223a9fca61877634e3489b1 Mon Sep 17 00:00:00 2001
From: John <ebusd@ebusd.eu>
Date: Sat, 23 Sep 2023 12:34:21 +0200
Subject: [PATCH] send empty topic instead of logging an error on messages
 without a single field (fixes #817)

---
 src/ebusd/mqtthandler.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/ebusd/mqtthandler.cpp b/src/ebusd/mqtthandler.cpp
index d8969d92..f508f322 100755
--- a/src/ebusd/mqtthandler.cpp
+++ b/src/ebusd/mqtthandler.cpp
@@ -1381,6 +1381,10 @@ void MqttHandler::publishMessage(const Message* message, ostringstream* updates,
       *updates << message->getCircuit() << UI_FIELD_SEPARATOR << message->getName() << UI_FIELD_SEPARATOR;
     }
     result_t result = message->decodeLastData(false, nullptr, -1, outputFormat, updates);
+    if (result == RESULT_EMPTY) {
+      publishEmptyTopic(getTopic(message));  // alternatively: , json ? "null" : "");
+      return;
+    }
     if (result != RESULT_OK) {
       logOtherError("mqtt", "decode %s %s: %s", message->getCircuit().c_str(), message->getName().c_str(),
           getResultCode(result));