Prep virtual mqtt_data prt3

tasmota/support.ino

@@ -1178,10 +1178,12 @@ uint32_t ResponseLength(void) {
 }
 
 void ResponseClear(void) {
+  // Reset string length to zero
   TasmotaGlobal.mqtt_data[0] = '\0';
 }
 
 void ResponseJsonStart(void) {
+  // Insert a JSON start bracket {
   TasmotaGlobal.mqtt_data[0] = '{';
 }
 

tasmota/support_command.ino

@@ -305,18 +305,6 @@ void CommandHandler(char* topicBuf, char* dataBuf, uint32_t data_len)
   }
 
   if (ResponseLength()) {
-/*
-    // Add "Command":"POWERONSTATE", like:
-    // 12:15:37 MQT: stat/wemos4/RESULT = {"Command":"POWERONSTATE","PowerOnState":3}
-    char json_command[TOPSZ];
-    snprintf_P(json_command, sizeof(json_command), PSTR("{\"" D_JSON_COMMAND "\":\"%s\","), type);
-    uint32_t jc_len = strlen(json_command);
-    uint32_t mq_len = ResponseLength() +1;
-    if (mq_len < ResponseSize() - jc_len) {
-      memmove(TasmotaGlobal.mqtt_data +jc_len -1, TasmotaGlobal.mqtt_data, mq_len);
-      memmove(TasmotaGlobal.mqtt_data, json_command, jc_len);
-    }
-*/
     MqttPublishPrefixTopicRulesProcess_P(RESULT_OR_STAT, type);
   }
   TasmotaGlobal.fallback_topic_flag = false;

tasmota/tasmota_globals.h

@@ -268,6 +268,7 @@ const uint16_t LOG_BUFFER_SIZE = 4000;         // Max number of characters in lo
 
 #ifndef MQTT_MAX_PACKET_SIZE
 #define MQTT_MAX_PACKET_SIZE        1200       // Bytes
+//#define MQTT_MAX_PACKET_SIZE        2048       // Bytes
 #endif
 #ifndef MQTT_KEEPALIVE
 #define MQTT_KEEPALIVE              30         // Seconds
@@ -288,6 +289,8 @@ const uint16_t LOG_BUFFER_SIZE = 4000;         // Max number of characters in lo
 #ifndef MESSZ
 //#define MESSZ                       1040     // Max number of characters in JSON message string (Hass discovery and nice MQTT_MAX_PACKET_SIZE = 1200)
 #define MESSZ                       (MQTT_MAX_PACKET_SIZE -TOPSZ -7)  // Max number of characters in JSON message string
+//#define MESSZ                       MQTT_MAX_PACKET_SIZE // Max number of characters in JSON message string
+//#define MESSZ                       2048       // Max number of characters in JSON message string
 #endif
 
 #ifndef USE_DEVICE_GROUPS

tasmota/xdrv_02_mqtt_1_file.ino

@@ -259,8 +259,7 @@ void CmndFileUpload(void) {
 
       /*
         The upload chunk size is the data size of the payload.
-        It can be larger than the download chunksize which is bound by MESSZ
+        The PubSubClient upload buffer with length MQTT_MAX_PACKET_SIZE contains
-        The PubSubClient upload buffer with length MQTT_MAX_PACKET_SIZE (1200) contains
           - Header of 5 bytes (MQTT_MAX_HEADER_SIZE)
           - Topic string terminated with a zero (stat/demo/FILEUPLOAD<null>)
           - Payload ({"Id":116,"Data":"<base64 encoded chunk_size>"}<null>) or (<binary data>)
@@ -378,36 +377,40 @@ void CmndFileDownload(void) {
 */
   if (FMqtt.file_buffer) {
     if (FMqtt.file_pos < FMqtt.file_size) {
+      uint32_t chunk_size = 4096;
+      if (!FMqtt.file_binary) {
+        /*
+          The download chunk size is the data size before it is encoded to base64.
+          The download buffer contains
+            - Payload ({"Id":117,"Data":"<base64 encoded mqtt_file_chuck_size>"}<null>)
+        */
+        chunk_size = (((ResponseSize() - FileTransferHeaderSize) / 4) * 3) -2;
+      }
       uint32_t bytes_left = FMqtt.file_size - FMqtt.file_pos;
-
-      /*
-        The download chunk size is the data size before it is encoded to base64.
-        It is smaller than the upload chunksize as it is bound by MESSZ
-        The download buffer with length MESSZ (1042) contains
-          - Payload ({"Id":117,"Data":"<base64 encoded mqtt_file_chuck_size>"}<null>)
-      */
-      const uint32_t mqtt_file_chunk_size = (((MESSZ - FileTransferHeaderSize) / 4) * 3) -2;
-      uint32_t chunk_size = (FMqtt.file_binary) ? 4096 : mqtt_file_chunk_size;
       uint32_t write_bytes = (bytes_left < chunk_size) ? bytes_left : chunk_size;
-
       uint8_t* buffer = FMqtt.file_buffer + FMqtt.file_pos;
       FMqtt.md5.add(buffer, write_bytes);
-
       FMqtt.file_pos += write_bytes;
 
       if (FMqtt.file_binary) {
+        // Binary data up to 4k
         MqttPublishPayloadPrefixTopic_P(STAT, XdrvMailbox.command, (const char*)buffer, write_bytes);
       } else {
         // {"Id":117,"Data":"CRJcTQ9fYGF ... OT1BRUlNUVVZXWFk="}
-        Response_P(PSTR("{\"Id\":%d,\"Data\":\""), FMqtt.file_id);  // FileTransferHeaderSize
+        char* base64_data = (char*)malloc(encode_base64_length(write_bytes) +2);
-        char base64_data[encode_base64_length(write_bytes)];
+        if (base64_data) {
-        encode_base64((unsigned char*)buffer, write_bytes, (unsigned char*)base64_data);
+          Response_P(PSTR("{\"Id\":%d,\"Data\":\""), FMqtt.file_id);  // FileTransferHeaderSize
-        ResponseAppend_P(base64_data);
+          encode_base64((unsigned char*)buffer, write_bytes, (unsigned char*)base64_data);
-        ResponseAppend_P("\"}");
+          ResponseAppend_P(base64_data);
-        MqttPublishPrefixTopic_P(STAT, XdrvMailbox.command);
+          ResponseAppend_P("\"}");
+          MqttPublishPrefixTopic_P(STAT, XdrvMailbox.command);
+          free(base64_data);
+        } else {
+          XdrvMailbox.payload = 0;                           // Abort
+        }
       }
       ResponseClear();
-      return;
+      if (XdrvMailbox.payload != 0) { return; }              // No error
     } else {
       FMqtt.md5.calculate();
 

tasmota/xdrv_02_mqtt_9_impl.ino

@@ -534,7 +534,6 @@ void MqttDataHandler(char* mqtt_topic, uint8_t* mqtt_data, unsigned int data_len
 
 //  AddLog(LOG_LEVEL_DEBUG, PSTR(D_LOG_MQTT "BufferSize %d, Topic |%s|, Length %d, data_len %d"), MqttClient.getBufferSize(), mqtt_topic, strlen(mqtt_topic), data_len);
 
-  // Save MQTT data ASAP as it's data is discarded by PubSubClient with next publish as used in MQTTlog
   char topic[TOPSZ];
 #ifdef USE_MQTT_AZURE_IOT
   // for Azure, we read the topic from the property of the message
@@ -557,8 +556,6 @@ void MqttDataHandler(char* mqtt_topic, uint8_t* mqtt_data, unsigned int data_len
   strlcpy(topic, mqtt_topic, sizeof(topic));
 #endif  // USE_MQTT_AZURE_IOT
   mqtt_data[data_len] = 0;
-  char data[data_len +1];
-  memcpy(data, mqtt_data, sizeof(data));
 
   if (Mqtt.disable_logging) {
     TasmotaGlobal.masterlog_level = LOG_LEVEL_DEBUG_MORE;  // Hide logging
@@ -568,12 +565,12 @@ void MqttDataHandler(char* mqtt_topic, uint8_t* mqtt_data, unsigned int data_len
   XdrvMailbox.index = strlen(topic);
   XdrvMailbox.data_len = data_len;
   XdrvMailbox.topic = topic;
-  XdrvMailbox.data = (char*)data;
+  XdrvMailbox.data = (char*)mqtt_data;
   if (XdrvCall(FUNC_MQTT_DATA)) { return; }
 
   ShowSource(SRC_MQTT);
 
-  CommandHandler(topic, data, data_len);
+  CommandHandler(topic, (char*)mqtt_data, data_len);
 
   if (Mqtt.disable_logging) {
     TasmotaGlobal.masterlog_level = LOG_LEVEL_NONE;  // Enable logging
@@ -608,7 +605,7 @@ void MqttPublishLoggingAsync(bool refresh) {
     char stopic[TOPSZ];
     GetTopic_P(stopic, STAT, TasmotaGlobal.mqtt_topic, PSTR("LOGGING"));
 //    strlcpy(TasmotaGlobal.mqtt_data, line, len);  // No JSON and ugly!!
-//    MqttPublishLib(stopic, (const uint8_t*)TasmotaGlobal.mqtt_data, strlen(TasmotaGlobal.mqtt_data), false);
+//    MqttPublishLib(stopic, (const uint8_t*)TasmotaGlobal.mqtt_data, ResponseLength(), false);
     MqttPublishLib(stopic, (const uint8_t*)line, len -1, false);
   }
 }

tasmota/xdrv_10_rules.ino

@@ -984,7 +984,7 @@ void RulesEvery100ms(void) {
     TasmotaGlobal.tele_period = 2;                                   // Do not allow HA updates during next function call
     XsnsNextCall(FUNC_JSON_APPEND, xsns_index);                      // ,"INA219":{"Voltage":4.494,"Current":0.020,"Power":0.089}
     TasmotaGlobal.tele_period = tele_period_save;
-    if (strlen(TasmotaGlobal.mqtt_data)) {
+    if (ResponseLength()) {
       ResponseJsonStart();                                           // {"INA219":{"Voltage":4.494,"Current":0.020,"Power":0.089}
       ResponseJsonEnd();
       RulesProcessEvent(TasmotaGlobal.mqtt_data);

tasmota/xdrv_10_scripter.ino

@@ -2424,9 +2424,9 @@ chknext:
                 }
               } else {
                 // preserve mqtt_data
-                char *mqd = (char*)malloc(MESSZ+2);
+                char *mqd = (char*)malloc(ResponseSize()+2);
                 if (mqd) {
-                  strlcpy(mqd, TasmotaGlobal.mqtt_data, MESSZ);
+                  strlcpy(mqd, TasmotaGlobal.mqtt_data, ResponseSize());
                   wd = mqd;
                   char *lwd = wd;
                   while (index) {
@@ -7703,7 +7703,7 @@ int32_t http_req(char *host, char *request) {
   }
 
 #ifdef USE_WEBSEND_RESPONSE
-  strlcpy(TasmotaGlobal.mqtt_data, http.getString().c_str(), MESSZ);
+  strlcpy(TasmotaGlobal.mqtt_data, http.getString().c_str(), ResponseSize());
   //AddLog(LOG_LEVEL_INFO, PSTR("HTTP RESULT %s"), TasmotaGlobal.mqtt_data);
   Run_Scripter(">E", 2, TasmotaGlobal.mqtt_data);
   glob_script_mem.glob_error = 0;

tasmota/xdrv_12_home_assistant.ino

@@ -876,7 +876,7 @@ void HAssAnnounceSensors(void)
     TasmotaGlobal.tele_period = 2;                                 // Do not allow HA updates during next function call
     XsnsNextCall(FUNC_JSON_APPEND, hass_xsns_index); // ,"INA219":{"Voltage":4.494,"Current":0.020,"Power":0.089}
     TasmotaGlobal.tele_period = tele_period_save;
-    size_t sensordata_len = strlen(TasmotaGlobal.mqtt_data);
+    size_t sensordata_len = ResponseLength();
     char sensordata[sensordata_len+2];   // dynamically adjust the size
     strcpy(sensordata, TasmotaGlobal.mqtt_data);    // we can use strcpy since the buffer has the right size
 

tasmota/xdrv_13_display.ino

@@ -1292,7 +1292,7 @@ void draw_dt_vars(void) {
 void DisplayDTVarsTeleperiod(void) {
   ResponseClear();
   MqttShowState();
-  uint32_t jlen = strlen(TasmotaGlobal.mqtt_data);
+  uint32_t jlen = ResponseLength();
 
   if (jlen < DTV_JSON_SIZE) {
     char *json = (char*)malloc(jlen + 2);

tasmota/xdrv_49_pid.ino

@@ -393,7 +393,7 @@ void PIDRun(void) {
   // `%topic%/PID {"power":"0.000"}`
   char str_buf[FLOATSZ];
   dtostrfd(power, 3, str_buf);
-  snprintf_P(TasmotaGlobal.mqtt_data, sizeof(TasmotaGlobal.mqtt_data), PSTR("{\"%s\":\"%s\"}"), "power", str_buf);
+  Response_P(PSTR("{\"%s\":\"%s\"}"), "power", str_buf);
   MqttPublishPrefixTopicRulesProcess_P(TELE, "PID");
 #endif // PID_DONT_USE_PID_TOPIC
 

tasmota/xdrv_79_esp32_ble.ino

@@ -3145,10 +3145,9 @@ static void BLEPostMQTTSeenDevices(int type) {
   nextSeenDev = 0;
 
   memset(TasmotaGlobal.mqtt_data, 0, sizeof(TasmotaGlobal.mqtt_data));
-  ResponseTime_P(PSTR(""));
+  int timelen = ResponseTime_P(PSTR(""));
-  int timelen = strlen(TasmotaGlobal.mqtt_data);
   char *dest = TasmotaGlobal.mqtt_data + timelen;
-  int maxlen = (sizeof(TasmotaGlobal.mqtt_data)-20) - timelen;
+  int maxlen = ResponseSize() -20 -timelen;
 
 //  if (!TasmotaGlobal.ota_state_flag){
   do {

tasmota/xdrv_99_debug.ino

@@ -512,10 +512,10 @@ void CmndCfgPoke(void)
 void CmndCfgXor(void)
 {
   if (XdrvMailbox.data_len > 0) {
-    Web.config_xor_on_set = XdrvMailbox.payload;
+    config_xor_on_set = XdrvMailbox.payload;
   }
   char temp[10];
-  snprintf_P(temp, sizeof(temp), PSTR("0x%02X"), Web.config_xor_on_set);
+  snprintf_P(temp, sizeof(temp), PSTR("0x%02X"), config_xor_on_set);
   ResponseCmndChar(temp);
 }
 #endif  // USE_WEBSERVER

tasmota/xsns_61_MI_NRF24.ino

@@ -1708,7 +1708,7 @@ void MINRFShow(bool json)
 
       ResponseAppend_P(PSTR(",\"%s-%02x%02x%02x\":"),kMINRFDeviceType[MIBLEsensors[i].type-1],MIBLEsensors[i].MAC[3],MIBLEsensors[i].MAC[4],MIBLEsensors[i].MAC[5]);
 
-      uint32_t _positionCurlyBracket = strlen(TasmotaGlobal.mqtt_data); // ... this will be a ',' first, but later be replaced
+      uint32_t _positionCurlyBracket = ResponseLength(); // ... this will be a ',' first, but later be replaced
 
       if((!MINRF.mode.triggeredTele && !MINRF.option.minimalSummary)||MINRF.mode.triggeredTele){
         bool tempHumSended = false;
@@ -1811,7 +1811,7 @@ void MINRFShow(bool json)
           }
         }
       }
-      if(_positionCurlyBracket==strlen(TasmotaGlobal.mqtt_data)) ResponseAppend_P(PSTR(",")); // write some random char, to be overwritten in the next step
+      if(_positionCurlyBracket==ResponseLength()) ResponseAppend_P(PSTR(",")); // write some random char, to be overwritten in the next step
       ResponseAppend_P(PSTR("}"));
       TasmotaGlobal.mqtt_data[_positionCurlyBracket] = '{';
       MIBLEsensors[i].eventType.raw = 0;

tasmota/xsns_62_MI_HM10.ino

@@ -459,7 +459,7 @@ void HM10_ReverseMAC(uint8_t _mac[]){
  */
 
 void HM10nullifyEndOfMQTT_DATA(){
-  char *p = TasmotaGlobal.mqtt_data + strlen(TasmotaGlobal.mqtt_data);
+  char *p = TasmotaGlobal.mqtt_data + ResponseLength();
   while(true){
     *p--;
     if(p[0]==':'){
@@ -1052,12 +1052,14 @@ void HM10addBeacon(uint8_t index, char* data){
 void HM10showScanResults(){
   size_t _size = MIBLEscanResult.size();
   ResponseAppend_P(PSTR(",\"BLEScan\":{\"Found\":%u,\"Devices\":["), _size);
+  bool add_comma = false;
   for(auto _scanResult : MIBLEscanResult){
     char _MAC[18];
     ToHex_P(_scanResult.MAC,6,_MAC,18,':');
-    ResponseAppend_P(PSTR("{\"MAC\":\"%s\",\"CID\":\"0x%04x\",\"SVC\":\"0x%04x\",\"UUID\":\"0x%04x\",\"RSSI\":%d},"), _MAC, _scanResult.CID, _scanResult.SVC, _scanResult.UUID, _scanResult.RSSI);
+    ResponseAppend_P(PSTR("%s{\"MAC\":\"%s\",\"CID\":\"0x%04x\",\"SVC\":\"0x%04x\",\"UUID\":\"0x%04x\",\"RSSI\":%d}"),
+      (add_comma)?",":"", _MAC, _scanResult.CID, _scanResult.SVC, _scanResult.UUID, _scanResult.RSSI);
+    add_comma = true;  
   }
-  if(_size != 0)TasmotaGlobal.mqtt_data[strlen(TasmotaGlobal.mqtt_data)-1] = 0; // delete last comma
   ResponseAppend_P(PSTR("]}"));
   MIBLEscanResult.clear();
   HM10.mode.shallShowScanResult = 0;
@@ -1065,12 +1067,13 @@ void HM10showScanResults(){
 
 void HM10showBlockList(){
   ResponseAppend_P(PSTR(",\"Block\":["));
+  bool add_comma = false;
   for(auto _scanResult : MIBLEBlockList){
     char _MAC[18];
     ToHex_P(_scanResult.buf,6,_MAC,18,':');
-    ResponseAppend_P(PSTR("\"%s\","), _MAC);
+    ResponseAppend_P(PSTR("%s\"%s\""), (add_comma)?",":"", _MAC);
+    add_comma = true;  
   }
-  if(MIBLEBlockList.size()!=0) TasmotaGlobal.mqtt_data[strlen(TasmotaGlobal.mqtt_data)-1] = 0; // delete last comma
   ResponseAppend_P(PSTR("]"));
   HM10.mode.shallShowBlockList = 0;
 }
@@ -1782,7 +1785,7 @@ void HM10Show(bool json)
         kHM10DeviceType[MIBLEsensors[i].type-1],
         MIBLEsensors[i].MAC[3], MIBLEsensors[i].MAC[4], MIBLEsensors[i].MAC[5]);
 
-      uint32_t _positionCurlyBracket = strlen(TasmotaGlobal.mqtt_data); // ... this will be a ',' first, but later be replaced
+      uint32_t _positionCurlyBracket = ResponseLength(); // ... this will be a ',' first, but later be replaced
 
       if((!HM10.mode.triggeredTele && !HM10.option.minimalSummary)||HM10.mode.triggeredTele){
         bool tempHumSended = false;
@@ -1910,7 +1913,7 @@ void HM10Show(bool json)
       if (HM10.option.showRSSI) ResponseAppend_P(PSTR(",\"RSSI\":%d"), MIBLEsensors[i].rssi);
 
 
-      if(_positionCurlyBracket==strlen(TasmotaGlobal.mqtt_data)) ResponseAppend_P(PSTR(",")); // write some random char, to be overwritten in the next step
+      if(_positionCurlyBracket==ResponseLength()) ResponseAppend_P(PSTR(",")); // write some random char, to be overwritten in the next step
       ResponseAppend_P(PSTR("}"));
       TasmotaGlobal.mqtt_data[_positionCurlyBracket] = '{';
       MIBLEsensors[i].eventType.raw = 0;

tasmota/xsns_62_esp32_mi.ino

@@ -634,7 +634,7 @@ int MI32_decryptPacket(char *_buf, uint16_t _bufSize, uint32_t _type){
  */
 
 void MI32nullifyEndOfMQTT_DATA(){
-  char *p = TasmotaGlobal.mqtt_data + strlen(TasmotaGlobal.mqtt_data);
+  char *p = TasmotaGlobal.mqtt_data + ResponseLength();
   while(true){
     *p--;
     if(p[0]==':'){
@@ -1598,12 +1598,14 @@ void MI32addBeacon(uint8_t index, char* data){
 void MI32showScanResults(){
   size_t _size = MIBLEscanResult.size();
   ResponseAppend_P(PSTR(",\"BLEScan\":{\"Found\":%u,\"Devices\":["), _size);
+  bool add_comma = false;
   for(auto _scanResult : MIBLEscanResult){
     char _MAC[18];
     ToHex_P(_scanResult.MAC,6,_MAC,18,':');
-    ResponseAppend_P(PSTR("{\"MAC\":\"%s\",\"CID\":\"0x%04x\",\"SVC\":\"0x%04x\",\"UUID\":\"0x%04x\",\"RSSI\":%d},"), _MAC, _scanResult.CID, _scanResult.SVC, _scanResult.UUID, _scanResult.RSSI);
+    ResponseAppend_P(PSTR("%s{\"MAC\":\"%s\",\"CID\":\"0x%04x\",\"SVC\":\"0x%04x\",\"UUID\":\"0x%04x\",\"RSSI\":%d}"),
+      (add_comma)?",":"", _MAC, _scanResult.CID, _scanResult.SVC, _scanResult.UUID, _scanResult.RSSI);
+    add_comma = true;  
   }
-  if(_size != 0)TasmotaGlobal.mqtt_data[strlen(TasmotaGlobal.mqtt_data)-1] = 0; // delete last comma
   ResponseAppend_P(PSTR("]}"));
   MIBLEscanResult.clear();
   MI32.mode.shallShowScanResult = 0;
@@ -1611,12 +1613,13 @@ void MI32showScanResults(){
 
 void MI32showBlockList(){
   ResponseAppend_P(PSTR(",\"Block\":["));
+  bool add_comma = false;
   for(auto _scanResult : MIBLEBlockList){
     char _MAC[18];
     ToHex_P(_scanResult.buf,6,_MAC,18,':');
-    ResponseAppend_P(PSTR("\"%s\","), _MAC);
+    ResponseAppend_P(PSTR("%s\"%s\""), (add_comma)?",":"", _MAC);
+    add_comma = true;  
   }
-  if(MIBLEBlockList.size()!=0) TasmotaGlobal.mqtt_data[strlen(TasmotaGlobal.mqtt_data)-1] = 0; // delete last comma
   ResponseAppend_P(PSTR("]"));
   MI32.mode.shallShowBlockList = 0;
 }
@@ -2027,7 +2030,7 @@ void MI32Show(bool json)
         kMI32DeviceType[MIBLEsensors[i].type-1],
         MIBLEsensors[i].MAC[3], MIBLEsensors[i].MAC[4], MIBLEsensors[i].MAC[5]);
 
-      uint32_t _positionCurlyBracket = strlen(TasmotaGlobal.mqtt_data); // ... this will be a ',' first, but later be replaced
+      uint32_t _positionCurlyBracket = ResponseLength(); // ... this will be a ',' first, but later be replaced
 
       if((!MI32.mode.triggeredTele && !MI32.option.minimalSummary)||MI32.mode.triggeredTele){
         bool tempHumSended = false;
@@ -2158,7 +2161,7 @@ void MI32Show(bool json)
       }
       if (MI32.option.showRSSI) ResponseAppend_P(PSTR(",\"RSSI\":%d"), MIBLEsensors[i].RSSI);
 
-      if(_positionCurlyBracket==strlen(TasmotaGlobal.mqtt_data)) ResponseAppend_P(PSTR(",")); // write some random char, to be overwritten in the next step
+      if(_positionCurlyBracket==ResponseLength()) ResponseAppend_P(PSTR(",")); // write some random char, to be overwritten in the next step
       ResponseAppend_P(PSTR("}"));
       TasmotaGlobal.mqtt_data[_positionCurlyBracket] = '{';
       MIBLEsensors[i].eventType.raw = 0;

tasmota/xsns_62_esp32_mi_ble.ino

@@ -1341,7 +1341,7 @@ int MIParsePacket(const uint8_t* slotmac, struct mi_beacon_data_t *parsed, const
  */
 
 void MI32nullifyEndOfMQTT_DATA(){
-  char *p = TasmotaGlobal.mqtt_data + strlen(TasmotaGlobal.mqtt_data);
+  char *p = TasmotaGlobal.mqtt_data + ResponseLength();
   while(true){
     *p--;
     if(p[0]==':'){

tasmota/xsns_75_prometheus.ino

@@ -132,7 +132,7 @@ void HandleMetrics(void) {
 
   ResponseClear();
   MqttShowSensor(); //Pull sensor data
-  char json[strlen(TasmotaGlobal.mqtt_data)+1];
+  char json[ResponseLength()+1];
   snprintf_P(json, sizeof(json), TasmotaGlobal.mqtt_data);
   String jsonStr = json;
   JsonParser parser((char *)jsonStr.c_str());