fixbug: getting empty value

main/protocols/mqtt_protocol.cc

@@ -39,7 +39,6 @@ bool MqttProtocol::StartMqttClient() {
     client_id_ = settings.GetString("client_id");
     username_ = settings.GetString("username");
     password_ = settings.GetString("password");
-    subscribe_topic_ = settings.GetString("subscribe_topic");
     publish_topic_ = settings.GetString("publish_topic");
 
     if (endpoint_.empty()) {
@@ -92,9 +91,6 @@ bool MqttProtocol::StartMqttClient() {
     }
 
     ESP_LOGI(TAG, "Connected to endpoint");
-    if (!subscribe_topic_.empty()) {
-        mqtt_->Subscribe(subscribe_topic_, 2);
-    }
     return true;
 }
 

main/protocols/mqtt_protocol.h

@@ -37,7 +37,6 @@ private:
     std::string client_id_;
     std::string username_;
     std::string password_;
-    std::string subscribe_topic_;
     std::string publish_topic_;
 
     std::mutex channel_mutex_;

main/settings.cc

@@ -31,7 +31,7 @@ std::string Settings::GetString(const std::string& key, const std::string& defau
     std::string value;
     value.resize(length);
     ESP_ERROR_CHECK(nvs_get_str(nvs_handle_, key.c_str(), value.data(), &length));
-    while (value.back() == '\0') {
+    while (!value.empty() && value.back() == '\0') {
         value.pop_back();
     }
     return value;