3 files changed, 17 insertions, 13 deletions
diff --git a/src/mqtt/qmqttconnection.cpp b/src/mqtt/qmqttconnection.cpp
index b9c821d..7092249 100644
--- a/src/mqtt/qmqttconnection.cpp
+++ b/src/mqtt/qmqttconnection.cpp
@@ -900,6 +900,7 @@ void QMqttConnection::readPublishProperties(QMqttPublishProperties &properties)
     m_missingData -= propertyLength;
 
     QMqttUserProperties userProperties;
+    QList<quint32> subscriptionIds;
 
     while (propertyLength > 0) {
         const quint8 propertyId = readBufferTyped<quint8>(&propertyLength);
@@ -942,7 +943,7 @@ void QMqttConnection::readPublishProperties(QMqttPublishProperties &properties)
             if (id < 0)
                 return; // readVariableByteInteger closes connection
             propertyLength -= idSize;
-            properties.setSubscriptionIdentifier(quint32(id));
+            subscriptionIds.append(quint32(id));
             break;
         }
         case 0x03: { // 3.3.2.3.9 Content Type
@@ -957,6 +958,9 @@ void QMqttConnection::readPublishProperties(QMqttPublishProperties &properties)
     }
     if (!userProperties.isEmpty())
         properties.setUserProperties(userProperties);
+
+    if (!subscriptionIds.isEmpty())
+        properties.setSubscriptionIdentifiers(subscriptionIds);
 }
 
 void QMqttConnection::readSubscriptionProperties(QMqttSubscription *sub)
@@ -1211,12 +1215,12 @@ QByteArray QMqttConnection::writePublishProperties(const QMqttPublishProperties
     }
 
     // 3.3.2.3.8 Subscription Identifier
-    if (properties.availableProperties() & QMqttPublishProperties::SubscriptionIdentifier &&
-            properties.subscriptionIdentifier() > 0) {
-        qCDebug(lcMqttConnectionVerbose) << "Publish Properties: Subscription ID:"
-                                         << properties.subscriptionIdentifier();
-        packet.append(char(0x0b));
-        packet.appendRawVariableInteger(properties.subscriptionIdentifier());
+    if (properties.availableProperties() & QMqttPublishProperties::SubscriptionIdentifier) {
+        for (auto id : properties.subscriptionIdentifiers()) {
+            qCDebug(lcMqttConnectionVerbose) << "Publish Properties: Subscription ID:" << id;
+            packet.append(char(0x0b));
+            packet.appendRawVariableInteger(id);
+        }
     }
 
     // 3.3.2.3.9 Content Type
diff --git a/src/mqtt/qmqttpublishproperties.cpp b/src/mqtt/qmqttpublishproperties.cpp
index d54fd35..66cc9e8 100644
--- a/src/mqtt/qmqttpublishproperties.cpp
+++ b/src/mqtt/qmqttpublishproperties.cpp
@@ -43,7 +43,7 @@ public:
     QString contentType;
     QByteArray correlationData;
     quint32 messageExpiry{0};
-    quint32 subscriptionIdentifier{0}; // Variable Integer
+    QList<quint32> subscriptionIdentifier;
     QMqttPublishProperties::PublishPropertyDetails details{QMqttPublishProperties::None};
     quint16 topicAlias{0};
     QMqtt::PayloadFormatIndicator payloadIndicator{QMqtt::PayloadFormatIndicator::Unspecified};
@@ -141,14 +141,14 @@ void QMqttPublishProperties::setUserProperties(const QMqttUserProperties &proper
     data->userProperties = properties;
 }
 
-quint32 QMqttPublishProperties::subscriptionIdentifier() const
+QList<quint32> QMqttPublishProperties::subscriptionIdentifiers() const
 {
     return data->subscriptionIdentifier;
 }
 
-void QMqttPublishProperties::setSubscriptionIdentifier(quint32 id)
+void QMqttPublishProperties::setSubscriptionIdentifiers(const QList<quint32> &id)
 {
-    if (id == 0) {
+    if (id.indexOf(0) != -1) {
         qCDebug(lcMqttClient) << "A subscription identifier with value 0 is not allowed.";
         return;
     }
diff --git a/src/mqtt/qmqttpublishproperties.h b/src/mqtt/qmqttpublishproperties.h
index 665311b..93ec6f9 100644
--- a/src/mqtt/qmqttpublishproperties.h
+++ b/src/mqtt/qmqttpublishproperties.h
@@ -82,8 +82,8 @@ public:
     QMqttUserProperties userProperties() const;
     void setUserProperties(const QMqttUserProperties &properties);
 
-    quint32 subscriptionIdentifier() const;
-    void setSubscriptionIdentifier(quint32 id);
+    QList<quint32> subscriptionIdentifiers() const;
+    void setSubscriptionIdentifiers(const QList<quint32> &id);
 
     QString contentType() const;
     void setContentType(const QString &type);