Avoid duplicate publish of config_version when config is updated

Author: mathieucarbou

src/app_config.cpp

@@ -31,7 +31,7 @@
 #define FACTORY_OFFSET    CONFIG_SIZE
 #define FACTORY_SIZE      1024
 
-uint32_t config_ver = 1;
+uint32_t config_ver = INITIAL_CONFIG_VERSION;
 
 // Wifi Network Strings
 String esid;

src/app_config.h

@@ -128,6 +128,8 @@ extern uint32_t flags;
 #define CONFIG_WIZARD               (1 << 25)
 #define CONFIG_DEFAULT_STATE        (1 << 26)
 
+#define INITIAL_CONFIG_VERSION  1
+
 inline bool config_emoncms_enabled() {
   return CONFIG_SERVICE_EMONCMS == (flags & CONFIG_SERVICE_EMONCMS);
 }

src/mqtt.cpp

@@ -519,9 +519,11 @@ mqtt_publish_config() {
   config_serialize(doc, true, false, true);
   mqtt_publish_json(doc, "/config");
 
-  String fulltopic = mqtt_topic + "/config_version";
-  String payload = String(config_version());
-  mqttclient.publish(fulltopic, payload, true);
+  if(config_version() == INITIAL_CONFIG_VERSION) {
+    String fulltopic = mqtt_topic + "/config_version";
+    String payload = String(config_version());
+    mqttclient.publish(fulltopic, payload, true);
+  }
 
   return true;
 }