From f2c04c550430a4cdaac12c2ca84bfed2da3b80ed Mon Sep 17 00:00:00 2001
From: Manuel <71137295+mverch67@users.noreply.github.com>
Date: Wed, 24 Jan 2024 21:01:50 +0100
Subject: [PATCH] fix MQTT crash (#3127)

---
 src/mqtt/MQTT.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/mqtt/MQTT.cpp b/src/mqtt/MQTT.cpp
index c91bdef29..d2d3f3b21 100644
--- a/src/mqtt/MQTT.cpp
+++ b/src/mqtt/MQTT.cpp
@@ -131,7 +131,10 @@ void MQTT::onReceive(char *topic, byte *payload, size_t length)
         }
         delete json_value;
     } else {
-        if (!pb_decode_from_bytes(payload, length, &meshtastic_ServiceEnvelope_msg, &e)) {
+        if (length == 0) {
+            LOG_WARN("Empty MQTT payload received, topic %s!\n", topic);
+            return;
+        } else if (!pb_decode_from_bytes(payload, length, &meshtastic_ServiceEnvelope_msg, &e)) {
             LOG_ERROR("Invalid MQTT service envelope, topic %s, len %u!\n", topic, length);
             return;
         } else {