From ca18d2c8419e3bfcd5c33a046d72baae093f9502 Mon Sep 17 00:00:00 2001
From: Thomas Basler <thomas@familie-basler.net>
Date: Thu, 4 Jan 2024 14:09:58 +0100
Subject: [PATCH] Prevent empty HASS auto discovery topics if memory allocation
 fails

---
 include/Utils.h        |  2 ++
 src/MqttHandleHass.cpp | 24 ++++++++++++++++++++++++
 src/Utils.cpp          | 11 +++++++++++
 3 files changed, 37 insertions(+)

diff --git a/include/Utils.h b/include/Utils.h
index 6de962b0..4d4bfee3 100644
--- a/include/Utils.h
+++ b/include/Utils.h
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
 
+#include <ArduinoJson.h>
 #include <cstdint>
 
 class Utils {
@@ -9,4 +10,5 @@ public:
     static uint64_t generateDtuSerial();
     static int getTimezoneOffset();
     static void restartDtu();
+    static bool checkJsonAlloc(const DynamicJsonDocument& doc, const char* function, const uint16_t line);
 };
diff --git a/src/MqttHandleHass.cpp b/src/MqttHandleHass.cpp
index 88553e15..0f5c293c 100644
--- a/src/MqttHandleHass.cpp
+++ b/src/MqttHandleHass.cpp
@@ -135,6 +135,10 @@ void MqttHandleHassClass::publishInverterField(std::shared_ptr<InverterAbstract>
         }
 
         DynamicJsonDocument root(1024);
+        if (!Utils::checkJsonAlloc(root, __FUNCTION__, __LINE__)) {
+            return;
+        }
+
         root["name"] = name;
         root["stat_t"] = stateTopic;
         root["uniq_id"] = serial + "_ch" + chanNum + "_" + fieldName;
@@ -179,6 +183,10 @@ void MqttHandleHassClass::publishInverterButton(std::shared_ptr<InverterAbstract
     const String cmdTopic = MqttSettings.getPrefix() + serial + "/" + subTopic;
 
     DynamicJsonDocument root(1024);
+    if (!Utils::checkJsonAlloc(root, __FUNCTION__, __LINE__)) {
+        return;
+    }
+
     root["name"] = caption;
     root["uniq_id"] = serial + "_" + buttonId;
     if (strcmp(icon, "")) {
@@ -217,6 +225,10 @@ void MqttHandleHassClass::publishInverterNumber(
     const String statTopic = MqttSettings.getPrefix() + serial + "/" + stateTopic;
 
     DynamicJsonDocument root(1024);
+    if (!Utils::checkJsonAlloc(root, __FUNCTION__, __LINE__)) {
+        return;
+    }
+
     root["name"] = caption;
     root["uniq_id"] = serial + "_" + buttonId;
     if (strcmp(icon, "")) {
@@ -251,6 +263,10 @@ void MqttHandleHassClass::publishInverterBinarySensor(std::shared_ptr<InverterAb
     const String statTopic = MqttSettings.getPrefix() + serial + "/" + subTopic;
 
     DynamicJsonDocument root(1024);
+    if (!Utils::checkJsonAlloc(root, __FUNCTION__, __LINE__)) {
+        return;
+    }
+
     root["name"] = caption;
     root["uniq_id"] = serial + "_" + sensorId;
     root["stat_t"] = statTopic;
@@ -275,6 +291,10 @@ void MqttHandleHassClass::publishDtuSensor(const char* name, const char* device_
     }
 
     DynamicJsonDocument root(1024);
+    if (!Utils::checkJsonAlloc(root, __FUNCTION__, __LINE__)) {
+        return;
+    }
+
     root["name"] = name;
     root["uniq_id"] = getDtuUniqueId() + "_" + id;
     if (strcmp(device_class, "")) {
@@ -317,6 +337,10 @@ void MqttHandleHassClass::publishDtuBinarySensor(const char* name, const char* d
     }
 
     DynamicJsonDocument root(1024);
+    if (!Utils::checkJsonAlloc(root, __FUNCTION__, __LINE__)) {
+        return;
+    }
+
     root["name"] = name;
     root["uniq_id"] = getDtuUniqueId() + "_" + id;
     root["stat_t"] = MqttSettings.getPrefix() + topic;
diff --git a/src/Utils.cpp b/src/Utils.cpp
index 89350961..386e0ed1 100644
--- a/src/Utils.cpp
+++ b/src/Utils.cpp
@@ -5,6 +5,7 @@
 #include "Utils.h"
 #include "Display_Graphic.h"
 #include "Led_Single.h"
+#include "MessageOutput.h"
 #include <Esp.h>
 
 uint32_t Utils::getChipId()
@@ -65,3 +66,13 @@ void Utils::restartDtu()
     yield();
     ESP.restart();
 }
+
+bool Utils::checkJsonAlloc(const DynamicJsonDocument& doc, const char* function, const uint16_t line)
+{
+    if (doc.capacity() == 0) {
+        MessageOutput.printf("Alloc failed: %s, %d\r\n", function, line);
+        return false;
+    }
+
+    return true;
+}