From 9a7b6a5e80b87df50451d7d5a17933f0465ad3c1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cornelius=20K=C3=B6pp?= <cornelius.koepp@fhdw.de>
Date: Fri, 1 Nov 2024 19:28:25 +0100
Subject: [PATCH] Fix `valueNoSendCompare`: DPT Conversion Fail Resulted in
 Setting KO to 0

---
 src/knx/group_object.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/knx/group_object.cpp b/src/knx/group_object.cpp
index 5a9ad28..d600bdc 100644
--- a/src/knx/group_object.cpp
+++ b/src/knx/group_object.cpp
@@ -301,7 +301,13 @@ bool GroupObject::valueNoSendCompare(const KNXValue& value, const Dpt& type)
         // convert new value to given dtp
         uint8_t newData[_dataLength];
         memset(newData, 0, _dataLength);
-        KNX_Encode_Value(value, newData, _dataLength, type);
+        const bool encodingDone = KNX_Encode_Value(value, newData, _dataLength, type);
+        if (!encodingDone)
+        {
+            // value conversion to DPT failed
+            // do NOT update the value of the KO!
+            return false;
+        }
 
         // check for change in converted value / update value on change only
         const bool dataChanged = memcmp(_data, newData, _dataLength);