From d3f2687e32719700b0ac9d4bc59c1d3632d02d90 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Holger=20Mu=CC=88ller?= <github@euhm.de>
Date: Tue, 12 Nov 2024 21:19:39 +0100
Subject: [PATCH 1/2] add return value to poll()

---
 src/MqttClient.cpp | 20 +++++++++++++++-----
 src/MqttClient.h   |  2 +-
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/MqttClient.cpp b/src/MqttClient.cpp
index 221b230..75cddf4 100644
--- a/src/MqttClient.cpp
+++ b/src/MqttClient.cpp
@@ -411,7 +411,12 @@ int MqttClient::unsubscribe(const String& topic)
   return unsubscribe(topic.c_str());
 }
 
-void MqttClient::poll()
+/**
+ * @brief  Call poll() regularly to receive MQTT messages and send MQTT keep alives.
+ * @return 0 - client is no longer connected.
+ *         1 - client is still connected.
+ */
+int MqttClient::poll()
 {
   if (clientAvailable() == 0 && !clientConnected()) {
     _rxState = MQTT_CLIENT_RX_STATE_READ_TYPE;
@@ -441,8 +446,7 @@ void MqttClient::poll()
         if (_rxLengthMultiplier > (128 * 128 * 128L)) {
           // malformed
           stop();
-
-          return;
+          return 0;
         }
 
         if ((b & 0x80) == 0) { // length done
@@ -469,7 +473,7 @@ void MqttClient::poll()
 
           if (malformedResponse) {
             stop();
-            return;
+            return 0;
           }
 
           if (_rxType == MQTT_PUBLISH) {
@@ -543,7 +547,7 @@ void MqttClient::poll()
           } else {
             if (_rxLength < _rxMessageTopicLength) {
               stop();
-              return;
+              return 0;
             }
           }
 
@@ -645,6 +649,8 @@ void MqttClient::poll()
       stop();
     }
   }
+
+  return _connected ? 1 : 0;
 }
 
 int MqttClient::connect(IPAddress ip, uint16_t port)
@@ -1150,6 +1156,10 @@ uint8_t MqttClient::clientConnected()
   return _client->connected();
 }
 
+/**
+ * @brief  Return number of available received bytes.
+ * @return Number of available bytes received.
+ */
 int MqttClient::clientAvailable()
 {
   return _client->available();
diff --git a/src/MqttClient.h b/src/MqttClient.h
index 522f023..8e13335 100644
--- a/src/MqttClient.h
+++ b/src/MqttClient.h
@@ -76,7 +76,7 @@ class MqttClient : public Client {
   int unsubscribe(const char* topic);
   int unsubscribe(const String& topic);
 
-  void poll();
+  int poll();
 
   // from Client
   virtual int connect(IPAddress ip, uint16_t port = 1883);

From 5eeec198713fbb8e6ac5f285de9e299dd3266a5e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Holger=20Mu=CC=88ller?= <github@euhm.de>
Date: Tue, 12 Nov 2024 21:36:04 +0100
Subject: [PATCH 2/2] add return value to poll()

---
 src/MqttClient.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/MqttClient.cpp b/src/MqttClient.cpp
index 75cddf4..e78a193 100644
--- a/src/MqttClient.cpp
+++ b/src/MqttClient.cpp
@@ -542,7 +542,7 @@ int MqttClient::poll()
           if (_rxMessageQoS) {
             if (_rxLength < (_rxMessageTopicLength + 2)) {
               stop();
-              return;
+              return 0;
             }
           } else {
             if (_rxLength < _rxMessageTopicLength) {