Merge remote-tracking branch 'origin/5.10' into dev

Change-Id: I2a9533a7b630538b422a1b254a5250067fc7bc16

32 files changed, 1529 insertions, 173 deletions

diff --git a/examples/mqtt/quicksubscription/qmlmqttclient.h b/examples/mqtt/quicksubscription/qmlmqttclient.h
index ffc45ea..2e1041b 100644
--- a/examples/mqtt/quicksubscription/qmlmqttclient.h
+++ b/examples/mqtt/quicksubscription/qmlmqttclient.h
@@ -60,7 +60,7 @@ class QmlMqttClient;
 class QmlMqttSubscription : public QObject
 {
     Q_OBJECT
-    Q_PROPERTY(QString topic MEMBER m_topic NOTIFY topicChanged)
+    Q_PROPERTY(QMqttTopicFilter topic MEMBER m_topic NOTIFY topicChanged)
 public:
     QmlMqttSubscription(QMqttSubscription *s, QmlMqttClient *c);
     ~QmlMqttSubscription();
@@ -76,7 +76,7 @@ private:
     Q_DISABLE_COPY(QmlMqttSubscription)
     QMqttSubscription *sub;
     QmlMqttClient *client;
-    QString m_topic;
+    QMqttTopicFilter m_topic;
 };
 
 class QmlMqttClient : public QMqttClient
diff --git a/examples/mqtt/simpleclient/mainwindow.cpp b/examples/mqtt/simpleclient/mainwindow.cpp
index 4f5e575..e40820b 100644
--- a/examples/mqtt/simpleclient/mainwindow.cpp
+++ b/examples/mqtt/simpleclient/mainwindow.cpp
@@ -68,10 +68,10 @@ MainWindow::MainWindow(QWidget *parent) :
     connect(m_client, &QMqttClient::stateChanged, this, &MainWindow::updateLogStateChange);
     connect(m_client, &QMqttClient::disconnected, this, &MainWindow::brokerDisconnected);
 
-    connect(m_client, &QMqttClient::messageReceived, this, [this](const QByteArray &message, const QString &topic) {
+    connect(m_client, &QMqttClient::messageReceived, this, [this](const QByteArray &message, const QMqttTopicName &topic) {
         const QString content = QDateTime::currentDateTime().toString()
                     + QLatin1String(" Received Topic: ")
-                    + topic
+                    + topic.name()
                     + QLatin1String(" Message: ")
                     + message
                     + QLatin1Char('\n');
diff --git a/examples/mqtt/subscriptions/mainwindow.cpp b/examples/mqtt/subscriptions/mainwindow.cpp
index 499d46a..e8fea99 100644
--- a/examples/mqtt/subscriptions/mainwindow.cpp
+++ b/examples/mqtt/subscriptions/mainwindow.cpp
@@ -69,10 +69,10 @@ MainWindow::MainWindow(QWidget *parent) :
     connect(m_client, &QMqttClient::stateChanged, this, &MainWindow::updateLogStateChange);
     connect(m_client, &QMqttClient::disconnected, this, &MainWindow::brokerDisconnected);
 
-    connect(m_client, &QMqttClient::messageReceived, this, [this](const QByteArray &message, const QString &topic) {
+    connect(m_client, &QMqttClient::messageReceived, this, [this](const QByteArray &message, const QMqttTopicName &topic) {
         const QString content = QDateTime::currentDateTime().toString()
                     + QLatin1String(" Received Topic: ")
-                    + topic
+                    + topic.name()
                     + QLatin1String(" Message: ")
                     + message
                     + QLatin1Char('\n');
@@ -156,7 +156,7 @@ void MainWindow::on_buttonSubscribe_clicked()
         return;
     }
     auto subWindow = new SubscriptionWindow(subscription);
-    subWindow->setWindowTitle(subscription->topic());
+    subWindow->setWindowTitle(subscription->topic().filter());
     subWindow->show();
 }
 
diff --git a/examples/mqtt/subscriptions/subscriptionwindow.cpp b/examples/mqtt/subscriptions/subscriptionwindow.cpp
index 0b6e0ba..5a87a51 100644
--- a/examples/mqtt/subscriptions/subscriptionwindow.cpp
+++ b/examples/mqtt/subscriptions/subscriptionwindow.cpp
@@ -58,7 +58,7 @@ SubscriptionWindow::SubscriptionWindow(QMqttSubscription *sub, QWidget *parent)
 {
     ui->setupUi(this);
 
-    ui->labelSub->setText(m_sub->topic());
+    ui->labelSub->setText(m_sub->topic().filter());
     ui->labelQoS->setText(QString::number(m_sub->qos()));
     updateStatus(m_sub->state());
     connect(m_sub, &QMqttSubscription::messageReceived, this, &SubscriptionWindow::updateMessage);
diff --git a/src/mqtt/doc/qtmqtt.qdocconf b/src/mqtt/doc/qtmqtt.qdocconf
index 6c62142..6fc50b4 100644
--- a/src/mqtt/doc/qtmqtt.qdocconf
+++ b/src/mqtt/doc/qtmqtt.qdocconf
@@ -37,6 +37,8 @@ imagedirs   += images \
                ../../../examples/mqtt/doc/images
 excludedirs += ../qt4support
 
+Cpp.ignoretokens += Q_MQTT_EXPORT
+
 depends += qtcore qtdoc qtnetwork qmake qtwebsockets
 
 #add generic thumbnail images for example documentation that does not have an image.
diff --git a/src/mqtt/mqtt.pro b/src/mqtt/mqtt.pro
index 3e71e07..c7866ba 100644
--- a/src/mqtt/mqtt.pro
+++ b/src/mqtt/mqtt.pro
@@ -11,7 +11,9 @@ PUBLIC_HEADERS += \
     qmqttglobal.h \
     qmqttclient.h \
     qmqttmessage.h \
-    qmqttsubscription.h
+    qmqttsubscription.h \
+    qmqtttopicfilter.h \
+    qmqtttopicname.h
 
 PRIVATE_HEADERS += \
     qmqttclient_p.h \
@@ -23,8 +25,10 @@ SOURCES += \
     qmqttclient.cpp \
     qmqttconnection.cpp \
     qmqttcontrolpacket.cpp \
+    qmqttmessage.cpp \
     qmqttsubscription.cpp \
-    qmqttmessage.cpp
+    qmqtttopicfilter.cpp \
+    qmqtttopicname.cpp
 
 HEADERS += $$PUBLIC_HEADERS $$PRIVATE_HEADERS
 
diff --git a/src/mqtt/qmqttclient.cpp b/src/mqtt/qmqttclient.cpp
index 69af887..23fb00f 100644
--- a/src/mqtt/qmqttclient.cpp
+++ b/src/mqtt/qmqttclient.cpp
@@ -236,7 +236,7 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \fn QMqttClient::messageReceived(const QByteArray &message, const QString &topic)
+    \fn QMqttClient::messageReceived(const QByteArray &message, const QMqttTopicName &topic)
 
     This signal is emitted when a new message has been received. The category of
     the message is specified by \a topic with the content being \a message.
@@ -271,10 +271,10 @@ QT_BEGIN_NAMESPACE
 /*!
     Creates a new MQTT client instance with the specified \a parent.
  */
-QMqttClient::QMqttClient(QObject *parent) : QObject(*(new QMqttClientPrivate), parent)
+QMqttClient::QMqttClient(QObject *parent) : QObject(*(new QMqttClientPrivate(this)), parent)
 {
     Q_D(QMqttClient);
-    d->m_connection.setClient(this, d);
+    d->m_connection.setClientPrivate(d);
 }
 
 /*!
@@ -313,7 +313,7 @@ QIODevice *QMqttClient::transport() const
     is subscribed twice, the return value points to the same subscription
     instance. The MQTT client is the owner of the subscription.
  */
-QMqttSubscription *QMqttClient::subscribe(const QString &topic, quint8 qos)
+QMqttSubscription *QMqttClient::subscribe(const QMqttTopicFilter &topic, quint8 qos)
 {
     Q_D(QMqttClient);
 
@@ -330,7 +330,7 @@ QMqttSubscription *QMqttClient::subscribe(const QString &topic, quint8 qos)
     \note If a client disconnects from a broker without unsubscribing, the
     broker will store all messages and publish them on the next reconnect.
  */
-void QMqttClient::unsubscribe(const QString &topic)
+void QMqttClient::unsubscribe(const QMqttTopicFilter &topic)
 {
     Q_D(QMqttClient);
     d->m_connection.sendControlUnsubscribe(topic);
@@ -345,7 +345,7 @@ void QMqttClient::unsubscribe(const QString &topic)
 
     Returns an ID that is used internally to identify the message.
  */
-qint32 QMqttClient::publish(const QString &topic, const QByteArray &message, quint8 qos, bool retain)
+qint32 QMqttClient::publish(const QMqttTopicName &topic, const QByteArray &message, quint8 qos, bool retain)
 {
     Q_D(QMqttClient);
     if (qos > 2)
@@ -419,8 +419,12 @@ void QMqttClient::connectToHost(bool encrypted, const QString &sslPeerName)
         d->setStateAndError(Disconnected, TransportInvalid);
         return;
     }
+    d->m_error = QMqttClient::NoError; // Fresh reconnect, unset error
     d->setStateAndError(Connecting);
 
+    if (d->m_cleanSession)
+        d->m_connection.cleanSubscriptions();
+
     if (!d->m_connection.ensureTransportOpen(sslPeerName)) {
         qWarning("Could not ensure that connection is open");
         d->setStateAndError(Disconnected, TransportInvalid);
@@ -670,13 +674,14 @@ void QMqttClient::setError(ClientError e)
     emit errorChanged(d->m_error);
 }
 
-QMqttClientPrivate::QMqttClientPrivate()
+QMqttClientPrivate::QMqttClientPrivate(QMqttClient *c)
     : QObjectPrivate()
 {
+    m_client = c;
     m_clientId = QUuid::createUuid().toString();
-    m_clientId.remove(QLatin1Char('{'), Qt::CaseInsensitive);
-    m_clientId.remove(QLatin1Char('}'), Qt::CaseInsensitive);
-    m_clientId.remove(QLatin1Char('-'), Qt::CaseInsensitive);
+    m_clientId.remove(QLatin1Char('{'));
+    m_clientId.remove(QLatin1Char('}'));
+    m_clientId.remove(QLatin1Char('-'));
     m_clientId.resize(23);
 }
 
@@ -690,7 +695,7 @@ void QMqttClientPrivate::setStateAndError(QMqttClient::ClientState s, QMqttClien
 
     if (s != m_state)
         q->setState(s);
-    if (m_error != QMqttClient::NoError && m_error != e)
+    if (e != QMqttClient::NoError && m_error != e)
         q->setError(e);
 }
 
diff --git a/src/mqtt/qmqttclient.h b/src/mqtt/qmqttclient.h
index 9a6990d..873f937 100644
--- a/src/mqtt/qmqttclient.h
+++ b/src/mqtt/qmqttclient.h
@@ -32,6 +32,7 @@
 
 #include <QtMqtt/qmqttglobal.h>
 #include <QtMqtt/QMqttSubscription>
+#include <QtMqtt/QMqttTopicFilter>
 
 #include <QtCore/QIODevice>
 #include <QtCore/QObject>
@@ -97,10 +98,10 @@ public:
     void setTransport(QIODevice *device, TransportType transport);
     QIODevice *transport() const;
 
-    QMqttSubscription *subscribe(const QString &topic, quint8 qos = 0);
-    void unsubscribe(const QString &topic);
+    QMqttSubscription *subscribe(const QMqttTopicFilter &topic, quint8 qos = 0);
+    void unsubscribe(const QMqttTopicFilter &topic);
 
-    Q_INVOKABLE qint32 publish(const QString &topic, const QByteArray &message = QByteArray(),
+    Q_INVOKABLE qint32 publish(const QMqttTopicName &topic, const QByteArray &message = QByteArray(),
                  quint8 qos = 0, bool retain = false);
     bool requestPing();
 
@@ -131,7 +132,7 @@ public:
 Q_SIGNALS:
     void connected();
     void disconnected();
-    void messageReceived(const QByteArray &message, const QString &topic = QString());
+    void messageReceived(const QByteArray &message, const QMqttTopicName &topic = QMqttTopicName());
     void messageSent(qint32 id);
     void pingResponseReceived();
     void brokerSessionRestored();
diff --git a/src/mqtt/qmqttclient_p.h b/src/mqtt/qmqttclient_p.h
index 8ae8d61..dc5760c 100644
--- a/src/mqtt/qmqttclient_p.h
+++ b/src/mqtt/qmqttclient_p.h
@@ -54,9 +54,10 @@ class QMqttClientPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QMqttClient)
 public:
-    QMqttClientPrivate();
+    QMqttClientPrivate(QMqttClient *c);
     ~QMqttClientPrivate() override;
     void setStateAndError(QMqttClient::ClientState s, QMqttClient::ClientError e = QMqttClient::NoError);
+    QMqttClient *m_client{nullptr};
     QString m_hostname;
     quint16 m_port{0};
     QMqttConnection m_connection;
diff --git a/src/mqtt/qmqttconnection.cpp b/src/mqtt/qmqttconnection.cpp
index 03ddab1..4db53c1 100644
--- a/src/mqtt/qmqttconnection.cpp
+++ b/src/mqtt/qmqttconnection.cpp
@@ -87,11 +87,15 @@ bool QMqttConnection::ensureTransport(bool createSecureIfNeeded)
 {
     qCDebug(lcMqttConnection) << Q_FUNC_INFO << m_transport;
 
-    if (m_transport)
-        return true;
+    if (m_transport) {
+        if (m_ownTransport)
+            delete m_transport;
+        else
+            return true;
+    }
 
     // We are asked to create a transport layer
-    if (m_client->hostname().isEmpty() || m_client->port() == 0) {
+    if (m_clientPrivate->m_hostname.isEmpty() || m_clientPrivate->m_port == 0) {
         qWarning("Trying to create a transport layer, but no hostname is specified");
         return false;
     }
@@ -102,7 +106,11 @@ bool QMqttConnection::ensureTransport(bool createSecureIfNeeded)
                                    new QTcpSocket();
     m_transport = socket;
     m_ownTransport = true;
-    m_transportType = createSecureIfNeeded ? QMqttClient::SecureSocket : QMqttClient::AbstractSocket;
+    m_transportType =
+#ifndef QT_NO_SSL
+        createSecureIfNeeded ? QMqttClient::SecureSocket :
+#endif
+                               QMqttClient::AbstractSocket;
 
     connect(socket, &QAbstractSocket::connected, this, &QMqttConnection::transportConnectionEstablished);
     connect(socket, &QAbstractSocket::disconnected, this, &QMqttConnection::transportConnectionClosed);
@@ -132,7 +140,7 @@ bool QMqttConnection::ensureTransportOpen(const QString &sslPeerName)
             return sendControlConnect();
 
         m_internalState = BrokerConnecting;
-        socket->connectToHost(m_client->hostname(), m_client->port());
+        socket->connectToHost(m_clientPrivate->m_hostname, m_clientPrivate->m_port);
     }
 #ifndef QT_NO_SSL
     else if (m_transportType == QMqttClient::SecureSocket) {
@@ -142,7 +150,7 @@ bool QMqttConnection::ensureTransportOpen(const QString &sslPeerName)
             return true;
 
         m_internalState = BrokerConnecting;
-        socket->connectToHostEncrypted(m_client->hostname(), m_client->port(), sslPeerName);
+        socket->connectToHostEncrypted(m_clientPrivate->m_hostname, m_clientPrivate->m_port, sslPeerName);
 
         if (!socket->waitForConnected()) {
             qWarning("Could not establish socket connection for transport");
@@ -170,50 +178,54 @@ bool QMqttConnection::sendControlConnect()
     // Variable header
     // 3.1.2.1 Protocol Name
     // 3.1.2.2 Protocol Level
-    const quint8 protocolVersion = m_client->protocolVersion();
-    if (protocolVersion == 3) {
+    switch (m_clientPrivate->m_protocolVersion) {
+    case QMqttClient::MQTT_3_1:
         packet.append("MQIsdp");
         packet.append(char(3)); // Version 3.1
-    } else if (protocolVersion == 4) {
+        break;
+    case QMqttClient::MQTT_3_1_1:
         packet.append("MQTT");
         packet.append(char(4)); // Version 3.1.1
-    } else {
-        qFatal("Illegal MQTT VERSION");
+        break;
+    default:
+        qCWarning(lcMqttConnection) << "Illegal MQTT Version";
+        m_clientPrivate->setStateAndError(QMqttClient::Disconnected, QMqttClient::InvalidProtocolVersion);
+        return false;
     }
 
     // 3.1.2.3 Connect Flags
     quint8 flags = 0;
     // Clean session
-    if (m_client->cleanSession())
+    if (m_clientPrivate->m_cleanSession)
         flags |= 1 << 1;
 
-    if (!m_client->willMessage().isEmpty()) {
+    if (!m_clientPrivate->m_willMessage.isEmpty()) {
         flags |= 1 << 2;
-        if (m_client->willQoS() > 2) {
+        if (m_clientPrivate->m_willQoS > 2) {
             qWarning("Will QoS does not have a valid value");
             return false;
         }
-        if (m_client->willQoS() == 1)
+        if (m_clientPrivate->m_willQoS == 1)
             flags |= 1 << 3;
-        else if (m_client->willQoS() == 2)
+        else if (m_clientPrivate->m_willQoS == 2)
             flags |= 1 << 4;
-        if (m_client->willRetain())
+        if (m_clientPrivate->m_willRetain)
             flags |= 1 << 5;
     }
-    if (m_client->username().size())
+    if (m_clientPrivate->m_username.size())
         flags |= 1 << 7;
 
-    if (m_client->password().size())
+    if (m_clientPrivate->m_password.size())
         flags |= 1 << 6;
 
     packet.append(char(flags));
 
     // 3.1.2.10 Keep Alive
-    packet.append(m_client->keepAlive());
+    packet.append(m_clientPrivate->m_keepAlive);
 
     // 3.1.3 Payload
     // 3.1.3.1 Client Identifier
-    const QByteArray clientStringArray = m_client->clientId().toUtf8();
+    const QByteArray clientStringArray = m_clientPrivate->m_clientId.toUtf8();
     if (clientStringArray.size()) {
         packet.append(clientStringArray);
     } else {
@@ -221,16 +233,16 @@ bool QMqttConnection::sendControlConnect()
         packet.append(char(0));
     }
 
-    if (!m_client->willMessage().isEmpty()) {
-        packet.append(m_client->willTopic().toUtf8());
-        packet.append(m_client->willMessage());
+    if (!m_clientPrivate->m_willMessage.isEmpty()) {
+        packet.append(m_clientPrivate->m_willTopic.toUtf8());
+        packet.append(m_clientPrivate->m_willMessage);
     }
 
-    if (m_client->username().size())
-        packet.append(m_client->username().toUtf8());
+    if (m_clientPrivate->m_username.size())
+        packet.append(m_clientPrivate->m_username.toUtf8());
 
-    if (m_client->password().size())
-        packet.append(m_client->password().toUtf8());
+    if (m_clientPrivate->m_password.size())
+        packet.append(m_clientPrivate->m_password.toUtf8());
 
     if (!writePacketToTransport(packet)) {
         qWarning("Could not write CONNECT frame to transport");
@@ -241,12 +253,12 @@ bool QMqttConnection::sendControlConnect()
     return true;
 }
 
-qint32 QMqttConnection::sendControlPublish(const QString &topic, const QByteArray &message, quint8 qos, bool retain)
+qint32 QMqttConnection::sendControlPublish(const QMqttTopicName &topic, const QByteArray &message, quint8 qos, bool retain)
 {
     qCDebug(lcMqttConnection) << Q_FUNC_INFO << topic << " Size:" << message.size() << " bytes."
                               << "QoS:" << qos << " Retain:" << retain;
 
-    if (topic.contains(QLatin1Char('#')) || topic.contains('+'))
+    if (!topic.isValid())
         return -1;
 
     quint8 header = QMqttControlPacket::PUBLISH;
@@ -259,15 +271,7 @@ qint32 QMqttConnection::sendControlPublish(const QString &topic, const QByteArra
         header |= 0x01;
 
     QSharedPointer<QMqttControlPacket> packet(new QMqttControlPacket(header));
-
-    QByteArray topicArray = topic.toUtf8();
-    const std::uint16_t u16max = std::numeric_limits<std::uint16_t>::max();
-    if (topicArray.size() > u16max) {
-        qWarning("Published topic is too long. Need to truncate");
-        topicArray.truncate(u16max);
-    }
-
-    packet->append(topicArray);
+    packet->append(topic.name().toUtf8());
     quint16 identifier = 0;
     if (qos > 0) {
         identifier = unusedPacketIdentifier();
@@ -318,7 +322,7 @@ bool QMqttConnection::sendControlPublishComp(quint16 id)
     return writePacketToTransport(packet);
 }
 
-QMqttSubscription *QMqttConnection::sendControlSubscribe(const QString &topic, quint8 qos)
+QMqttSubscription *QMqttConnection::sendControlSubscribe(const QMqttTopicFilter &topic, quint8 qos)
 {
     qCDebug(lcMqttConnection) << Q_FUNC_INFO << " Topic:" << topic << " qos:" << qos;
 
@@ -336,13 +340,12 @@ QMqttSubscription *QMqttConnection::sendControlSubscribe(const QString &topic, q
     packet.append(identifier);
 
     // Overflow protection
-    QByteArray topicArray = topic.toUtf8();
-    if (topicArray.size() > std::numeric_limits<std::uint16_t>::max()) {
-        qWarning("Subscribed topic is too long.");
+    if (!topic.isValid()) {
+        qWarning("Subscribed topic filter is not valid.");
         return nullptr;
     }
 
-    packet.append(topicArray);
+    packet.append(topic.filter().toUtf8());
 
     switch (qos) {
     case 0: packet.append(char(0x0)); break;
@@ -352,8 +355,8 @@ QMqttSubscription *QMqttConnection::sendControlSubscribe(const QString &topic, q
     }
 
     auto result = new QMqttSubscription(this);
-    result->setTopic(QString::fromUtf8(topicArray));
-    result->setClient(m_client);
+    result->setTopic(topic);
+    result->setClient(m_clientPrivate->m_client);
     result->setQos(qos);
     result->setState(QMqttSubscription::SubscriptionPending);
 
@@ -368,12 +371,12 @@ QMqttSubscription *QMqttConnection::sendControlSubscribe(const QString &topic, q
     return result;
 }
 
-bool QMqttConnection::sendControlUnsubscribe(const QString &topic)
+bool QMqttConnection::sendControlUnsubscribe(const QMqttTopicFilter &topic)
 {
     qCDebug(lcMqttConnection) << Q_FUNC_INFO << " Topic:" << topic;
 
     // MQTT-3.10.3-2
-    if (topic.isEmpty())
+    if (!topic.isValid())
         return false;
 
     if (!m_activeSubscriptions.contains(topic))
@@ -394,7 +397,7 @@ bool QMqttConnection::sendControlUnsubscribe(const QString &topic)
 
     packet.append(identifier);
 
-    packet.append(topic.toUtf8());
+    packet.append(topic.filter().toUtf8());
     auto sub = m_activeSubscriptions[topic];
     sub->setState(QMqttSubscription::UnsubscriptionPending);
 
@@ -446,9 +449,8 @@ bool QMqttConnection::sendControlDisconnect()
     return false;
 }
 
-void QMqttConnection::setClient(QMqttClient *client, QMqttClientPrivate *clientPrivate)
+void QMqttConnection::setClientPrivate(QMqttClientPrivate *clientPrivate)
 {
-    m_client = client;
     m_clientPrivate = clientPrivate;
 }
 
@@ -477,6 +479,21 @@ quint16 QMqttConnection::unusedPacketIdentifier() const
     return packetIdentifierCounter;
 }
 
+void QMqttConnection::cleanSubscriptions()
+{
+    for (auto item : m_pendingSubscriptionAck)
+        item->setState(QMqttSubscription::Unsubscribed);
+    m_pendingSubscriptionAck.clear();
+
+    for (auto item : m_pendingUnsubscriptions)
+        item->setState(QMqttSubscription::Unsubscribed);
+    m_pendingUnsubscriptions.clear();
+
+    for (auto item : m_activeSubscriptions)
+        item->setState(QMqttSubscription::Unsubscribed);
+    m_activeSubscriptions.clear();
+}
+
 void QMqttConnection::transportConnectionEstablished()
 {
     if (m_internalState != BrokerConnecting) {
@@ -495,8 +512,7 @@ void QMqttConnection::transportConnectionClosed()
 {
     m_readBuffer.clear();
     m_pingTimer.stop();
-    m_client->setState(QMqttClient::Disconnected);
-    m_client->setError(QMqttClient::TransportInvalid);
+    m_clientPrivate->setStateAndError(QMqttClient::Disconnected, QMqttClient::TransportInvalid);
 }
 
 void QMqttConnection::transportReadReady()
@@ -544,9 +560,13 @@ void QMqttConnection::finalize_connack()
 
     // MQTT-3.2.2-1 & MQTT-3.2.2-2
     if (sessionPresent) {
-        emit m_client->brokerSessionRestored();
-        if (m_client->cleanSession())
+        emit m_clientPrivate->m_client->brokerSessionRestored();
+        if (m_clientPrivate->m_cleanSession)
             qWarning("Connected with a clean session, ack contains session present");
+    } else {
+        // MQTT-4.1.0.-1 MQTT-4.1.0-2 Session not stored on broker side
+        // regardless whether cleanSession is false
+        cleanSubscriptions();
     }
 
     quint8 connectResultValue;
@@ -562,9 +582,9 @@ void QMqttConnection::finalize_connack()
         return;
     }
     m_internalState = BrokerConnected;
-    m_client->setState(QMqttClient::Connected);
+    m_clientPrivate->setStateAndError(QMqttClient::Connected);
 
-    m_pingTimer.setInterval(m_client->keepAlive() * 1000);
+    m_pingTimer.setInterval(m_clientPrivate->m_keepAlive * 1000);
     m_pingTimer.start();
 }
 
@@ -617,7 +637,7 @@ void QMqttConnection::finalize_publish()
 {
     // String topic
     const quint16 topicLength = qFromBigEndian<quint16>(reinterpret_cast<const quint16 *>(readBuffer(2).constData()));
-    const QString topic = QString::fromUtf8(reinterpret_cast<const char *>(readBuffer(topicLength).constData()));
+    const QMqttTopicName topic = QString::fromUtf8(reinterpret_cast<const char *>(readBuffer(topicLength).constData()));
 
     quint16 id = 0;
     if (m_currentPublish.qos > 0) {
@@ -631,39 +651,14 @@ void QMqttConnection::finalize_publish()
     qCDebug(lcMqttConnectionVerbose) << "Finalize PUBLISH: topic:" << topic
                                      << " payloadLength:" << payloadLength;;
 
-    emit m_client->messageReceived(message, topic);
+    emit m_clientPrivate->m_client->messageReceived(message, topic);
 
     QMqttMessage qmsg(topic, message, id, m_currentPublish.qos,
                       m_currentPublish.dup, m_currentPublish.retain);
 
     for (auto sub = m_activeSubscriptions.constBegin(); sub != m_activeSubscriptions.constEnd(); sub++) {
-        const QString subTopic = sub.key();
-
-        if (subTopic == topic) {
-            emit sub.value()->messageReceived(qmsg);
-            continue;
-        } else if (subTopic.endsWith(QLatin1Char('#')) && topic.startsWith(subTopic.leftRef(subTopic.size() - 1))) {
-            emit sub.value()->messageReceived(qmsg);
-            continue;
-        }
-
-        if (!subTopic.contains(QLatin1Char('+')))
-            continue;
-
-        const QVector<QStringRef> subTopicSplit = subTopic.splitRef(QLatin1Char('/'));
-        const QVector<QStringRef> topicSplit = topic.splitRef(QLatin1Char('/'));
-        if (subTopicSplit.size() != topicSplit.size())
-            continue;
-        bool match = true;
-        for (int i = 0; i < subTopicSplit.size() && match; ++i) {
-            if (subTopicSplit.at(i) == QLatin1Char('+') || subTopicSplit.at(i) == topicSplit.at(i))
-                continue;
-            match = false;
-        }
-
-        if (match) {
+        if (sub.key().match(topic))
             emit sub.value()->messageReceived(qmsg);
-        }
     }
 
     if (m_currentPublish.qos == 1)
@@ -684,7 +679,7 @@ void QMqttConnection::finalize_pubAckRecComp()
         auto pendingRelease = m_pendingReleaseMessages.take(id);
         if (!pendingRelease)
             qWarning("Received PUBCOMP for unknown released message");
-        emit m_client->messageSent(id);
+        emit m_clientPrivate->m_client->messageSent(id);
         return;
     }
 
@@ -699,7 +694,7 @@ void QMqttConnection::finalize_pubAckRecComp()
         sendControlPublishRelease(id);
     } else {
         qCDebug(lcMqttConnectionVerbose) << " PUBACK:" << id;
-        emit m_client->messageSent(id);
+        emit m_clientPrivate->m_client->messageSent(id);
     }
 }
 
@@ -726,7 +721,7 @@ void QMqttConnection::finalize_pingresp()
         closeConnection(QMqttClient::ProtocolViolation);
         return;
     }
-    emit m_client->pingResponseReceived();
+    emit m_clientPrivate->m_client->pingResponseReceived();
 }
 
 void QMqttConnection::processData()
@@ -769,12 +764,24 @@ void QMqttConnection::processData()
 
     // MQTT-2.2 A fixed header of a control packet must be at least 2 bytes. If the payload is
     // longer than 127 bytes the header can be up to 5 bytes long.
-    const int readBufferSize = m_readBuffer.size();
-    if (readBufferSize < 2
-        || (readBufferSize == 2 && (m_readBuffer.at(1) & 128) != 0)
-        || (readBufferSize == 3 && (m_readBuffer.at(2) & 128) != 0)
-        || (readBufferSize == 4 && (m_readBuffer.at(3) & 128) != 0)) {
+    switch (m_readBuffer.size()) {
+    case 0:
+    case 1:
         return;
+    case 2:
+        if ((m_readBuffer.at(1) & 128) != 0)
+            return;
+        break;
+    case 3:
+        if ((m_readBuffer.at(1) & 128) != 0 && (m_readBuffer.at(2) & 128) != 0)
+            return;
+        break;
+    case 4:
+        if ((m_readBuffer.at(1) & 128) != 0 && (m_readBuffer.at(2) & 128) != 0 && (m_readBuffer.at(3) & 128) != 0)
+            return;
+        break;
+    default:
+        break;
     }
 
     readBuffer((char*)&m_currentPacket, 1);
diff --git a/src/mqtt/qmqttconnection_p.h b/src/mqtt/qmqttconnection_p.h
index d747771..cf9c912 100644
--- a/src/mqtt/qmqttconnection_p.h
+++ b/src/mqtt/qmqttconnection_p.h
@@ -77,21 +77,23 @@ public:
     bool ensureTransportOpen(const QString &sslPeerName = QString());
 
     bool sendControlConnect();
-    qint32 sendControlPublish(const QString &topic, const QByteArray &message, quint8 qos = 0, bool retain = false);
+    qint32 sendControlPublish(const QMqttTopicName &topic, const QByteArray &message, quint8 qos = 0, bool retain = false);
     bool sendControlPublishAcknowledge(quint16 id);
     bool sendControlPublishRelease(quint16 id);
     bool sendControlPublishReceive(quint16 id);
     bool sendControlPublishComp(quint16 id);
-    QMqttSubscription *sendControlSubscribe(const QString &topic, quint8 qos = 0);
-    bool sendControlUnsubscribe(const QString &topic);
+    QMqttSubscription *sendControlSubscribe(const QMqttTopicFilter &topic, quint8 qos = 0);
+    bool sendControlUnsubscribe(const QMqttTopicFilter &topic);
     bool sendControlPingRequest();
     bool sendControlDisconnect();
 
-    void setClient(QMqttClient *client, QMqttClientPrivate *clientPrivate);
+    void setClientPrivate(QMqttClientPrivate *clientPrivate);
 
     inline quint16 unusedPacketIdentifier() const;
     inline InternalConnectionState internalState() const { return m_internalState; }
 
+    void cleanSubscriptions();
+
 public Q_SLOTS:
     void transportConnectionEstablished();
     void transportConnectionClosed();
@@ -101,7 +103,6 @@ public:
     QIODevice *m_transport{nullptr};
     QMqttClient::TransportType m_transportType{QMqttClient::IODevice};
     bool m_ownTransport{false};
-    QMqttClient *m_client{nullptr};
     QMqttClientPrivate *m_clientPrivate{nullptr};
 private:
     Q_DISABLE_COPY(QMqttConnection)
@@ -130,7 +131,7 @@ private:
     bool writePacketToTransport(const QMqttControlPacket &p);
     QMap<quint16, QMqttSubscription *> m_pendingSubscriptionAck;
     QMap<quint16, QMqttSubscription *> m_pendingUnsubscriptions;
-    QMap<QString, QMqttSubscription *> m_activeSubscriptions;
+    QMap<QMqttTopicFilter, QMqttSubscription *> m_activeSubscriptions;
     QMap<quint16, QSharedPointer<QMqttControlPacket>> m_pendingMessages;
     QMap<quint16, QSharedPointer<QMqttControlPacket>> m_pendingReleaseMessages;
     InternalConnectionState m_internalState{BrokerDisconnected};
diff --git a/src/mqtt/qmqttcontrolpacket.cpp b/src/mqtt/qmqttcontrolpacket.cpp
index f929f37..3d0db8d 100644
--- a/src/mqtt/qmqttcontrolpacket.cpp
+++ b/src/mqtt/qmqttcontrolpacket.cpp
@@ -80,12 +80,12 @@ void QMqttControlPacket::append(quint16 value)
 void QMqttControlPacket::append(const QByteArray &data)
 {
     append(static_cast<quint16>(data.size()));
-    m_payload.append(data.constData());
+    m_payload.append(data);
 }
 
 void QMqttControlPacket::appendRaw(const QByteArray &data)
 {
-    m_payload.append(data.constData());
+    m_payload.append(data);
 }
 
 QByteArray QMqttControlPacket::serialize() const
diff --git a/src/mqtt/qmqttmessage.cpp b/src/mqtt/qmqttmessage.cpp
index 1bdbdf7..25ed768 100644
--- a/src/mqtt/qmqttmessage.cpp
+++ b/src/mqtt/qmqttmessage.cpp
@@ -86,44 +86,117 @@ QT_BEGIN_NAMESPACE
     live update. A broker can store only one retained message per topic.
 */
 
-QByteArray QMqttMessage::payload() const
+class QMqttMessagePrivate : public QSharedData
 {
-    return m_payload;
+public:
+    bool operator==(const QMqttMessagePrivate &other) {
+        return m_topic == other.m_topic &&
+                m_payload == other.m_payload &&
+                m_id == other.m_id &&
+                m_qos == other.m_qos &&
+                m_duplicate == other.m_duplicate &&
+                m_retain == other.m_retain;
+    }
+    QMqttTopicName m_topic;
+    QByteArray m_payload;
+    quint16 m_id{0};
+    quint8 m_qos{0};
+    bool m_duplicate{false};
+    bool m_retain{false};
+};
+
+/*!
+    Creates a new MQTT message.
+*/
+QMqttMessage::QMqttMessage()
+    : d(new QMqttMessagePrivate())
+{
+}
+
+/*!
+    Constructs a new MQTT message that is a copy of \a other.
+*/
+QMqttMessage::QMqttMessage(const QMqttMessage &other)
+    : d(other.d)
+{
+}
+
+QMqttMessage::~QMqttMessage()
+{
+}
+
+/*!
+    Makes this object a copy of \a other and returns the new value of this object.
+*/
+QMqttMessage &QMqttMessage::operator=(const QMqttMessage &other)
+{
+    d = other.d;
+    return *this;
+}
+
+/*!
+    Returns \c true if the message and \a other are equal, otherwise returns \c false.
+*/
+bool QMqttMessage::operator==(const QMqttMessage &other) const
+{
+    return d == other.d;
+}
+
+/*!
+    Returns \c true if the message and \a other are not equal, otherwise returns \c false.
+*/
+bool QMqttMessage::operator!=(const QMqttMessage &other) const
+{
+    return !(*this == other);
+}
+
+const QByteArray &QMqttMessage::payload() const
+{
+    return d->m_payload;
 }
 
 quint8 QMqttMessage::qos() const
 {
-    return m_qos;
+    return d->m_qos;
 }
 
 quint16 QMqttMessage::id() const
 {
-    return m_id;
+    return d->m_id;
 }
 
-QString QMqttMessage::topic() const
+QMqttTopicName QMqttMessage::topic() const
 {
-    return m_topic;
+    return d->m_topic;
 }
 
 bool QMqttMessage::duplicate() const
 {
-    return m_duplicate;
+    return d->m_duplicate;
 }
 
 bool QMqttMessage::retain() const
 {
-    return m_retain;
+    return d->m_retain;
 }
 
-QMqttMessage::QMqttMessage(const QString &topic, const QByteArray &content, quint16 id, quint8 qos, bool dup, bool retain)
-    : m_topic(topic)
-    , m_payload(content)
-    , m_id(id)
-    , m_qos(qos)
-    , m_duplicate(dup)
-    , m_retain(retain)
+/*!
+    \internal
+    Constructs a new MQTT message with \a content on the topic \a topic.
+    Furthermore the properties \a id, \a qos, \a dup, \a retain must be specified.
+
+    This constructor is mostly used internally to construct a QMqttMessage at message
+    receival.
+*/
+QMqttMessage::QMqttMessage(const QMqttTopicName &topic, const QByteArray &content, quint16 id, quint8 qos, bool dup, bool retain)
+    : d(new QMqttMessagePrivate)
 {
+    d->m_topic = topic;
+    d->m_payload = content;
+    d->m_id = id;
+    d->m_qos = qos;
+    d->m_duplicate = dup;
+    d->m_retain = retain;
 }
 
 QT_END_NAMESPACE
diff --git a/src/mqtt/qmqttmessage.h b/src/mqtt/qmqttmessage.h
index 3f25d08..509e631 100644
--- a/src/mqtt/qmqttmessage.h
+++ b/src/mqtt/qmqttmessage.h
@@ -32,40 +32,51 @@
 
 #include "qmqttglobal.h"
 
+#include <QtMqtt/QMqttTopicName>
+
 #include <QtCore/QObject>
+#include <QtCore/QSharedDataPointer>
 
 QT_BEGIN_NAMESPACE
 
+class QMqttMessagePrivate;
+
 class Q_MQTT_EXPORT QMqttMessage
 {
     Q_GADGET
-    Q_PROPERTY(QString topic READ topic CONSTANT)
+    Q_PROPERTY(QMqttTopicName topic READ topic CONSTANT)
     Q_PROPERTY(QByteArray payload READ payload CONSTANT)
     Q_PROPERTY(quint16 id READ id CONSTANT)
     Q_PROPERTY(quint8 qos READ qos CONSTANT)
     Q_PROPERTY(bool duplicate READ duplicate CONSTANT)
     Q_PROPERTY(bool retain READ retain CONSTANT)
+
 public:
-    QByteArray payload() const;
+    QMqttMessage();
+    QMqttMessage(const QMqttMessage& other);
+    ~QMqttMessage();
+
+    QMqttMessage& operator=(const QMqttMessage &other);
+    bool operator==(const QMqttMessage &other) const;
+    inline bool operator!=(const QMqttMessage &other) const;
+
+    const QByteArray &payload() const;
     quint8 qos() const;
     quint16 id() const;
-    QString topic() const;
+    QMqttTopicName topic() const;
     bool duplicate() const;
     bool retain() const;
 
 private:
     friend class QMqttConnection;
-    explicit QMqttMessage(const QString &topic, const QByteArray &payload,
+    QMqttMessage(const QMqttTopicName &topic, const QByteArray &payload,
                           quint16 id, quint8 qos,
                           bool dup, bool retain);
-    QString m_topic;
-    QByteArray m_payload;
-    quint16 m_id;
-    quint8 m_qos;
-    bool m_duplicate;
-    bool m_retain;
+    QExplicitlySharedDataPointer<QMqttMessagePrivate> d;
 };
 
 QT_END_NAMESPACE
 
+Q_DECLARE_METATYPE(QMqttMessage)
+
 #endif // QMQTTMESSAGE_H
diff --git a/src/mqtt/qmqttsubscription.cpp b/src/mqtt/qmqttsubscription.cpp
index 80e8aed..750707f 100644
--- a/src/mqtt/qmqttsubscription.cpp
+++ b/src/mqtt/qmqttsubscription.cpp
@@ -108,7 +108,7 @@ QMqttSubscription::SubscriptionState QMqttSubscription::state() const
     return d->m_state;
 }
 
-QString QMqttSubscription::topic() const
+QMqttTopicFilter QMqttSubscription::topic() const
 {
     Q_D(const QMqttSubscription);
     return d->m_topic;
@@ -143,7 +143,7 @@ void QMqttSubscription::unsubscribe()
     setState(Unsubscribed);
 }
 
-void QMqttSubscription::setTopic(const QString &topic)
+void QMqttSubscription::setTopic(const QMqttTopicFilter &topic)
 {
     Q_D(QMqttSubscription);
     d->m_topic = topic;
diff --git a/src/mqtt/qmqttsubscription.h b/src/mqtt/qmqttsubscription.h
index a4dc53b..054e4ea 100644
--- a/src/mqtt/qmqttsubscription.h
+++ b/src/mqtt/qmqttsubscription.h
@@ -33,6 +33,8 @@
 #include "qmqttmessage.h"
 
 #include <QtMqtt/qmqttglobal.h>
+#include <QtMqtt/QMqttTopicFilter>
+
 #include <QtCore/QObject>
 
 QT_BEGIN_NAMESPACE
@@ -46,7 +48,7 @@ class Q_MQTT_EXPORT QMqttSubscription : public QObject
     Q_ENUMS(SubscriptionState)
     Q_PROPERTY(SubscriptionState state READ state NOTIFY stateChanged)
     Q_PROPERTY(quint8 qos READ qos NOTIFY qosChanged)
-    Q_PROPERTY(QString topic READ topic)
+    Q_PROPERTY(QMqttTopicFilter topic READ topic)
 public:
     ~QMqttSubscription() override;
     enum SubscriptionState {
@@ -58,7 +60,7 @@ public:
     };
 
     SubscriptionState state() const;
-    QString topic() const;
+    QMqttTopicFilter topic() const;
     quint8 qos() const;
 
 Q_SIGNALS:
@@ -73,7 +75,7 @@ private:
     Q_DECLARE_PRIVATE(QMqttSubscription)
     Q_DISABLE_COPY(QMqttSubscription)
     void setState(SubscriptionState state);
-    void setTopic(const QString &topic);
+    void setTopic(const QMqttTopicFilter &topic);
     void setClient(QMqttClient *client);
     void setQos(quint8 qos);
     friend class QMqttConnection;
diff --git a/src/mqtt/qmqttsubscription_p.h b/src/mqtt/qmqttsubscription_p.h
index 104c4fc..89ffdf0 100644
--- a/src/mqtt/qmqttsubscription_p.h
+++ b/src/mqtt/qmqttsubscription_p.h
@@ -54,7 +54,7 @@ public:
     ~QMqttSubscriptionPrivate() override = default;
     QMqttClient *m_client{nullptr};
     QMqttSubscription::SubscriptionState m_state{QMqttSubscription::Unsubscribed};
-    QString m_topic;
+    QMqttTopicFilter m_topic;
     quint8 m_qos{0};
 };
 
diff --git a/src/mqtt/qmqtttopicfilter.cpp b/src/mqtt/qmqtttopicfilter.cpp
new file mode 100644
index 0000000..d2071c7
--- /dev/null
+++ b/src/mqtt/qmqtttopicfilter.cpp
@@ -0,0 +1,314 @@
+/******************************************************************************
+**
+** Copyright (C) 2017 Lorenz Haas
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtMqtt module.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+******************************************************************************/
+
+#include "qmqtttopicfilter.h"
+
+#include <QtCore/QDebug>
+#include <QtCore/QVector>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \class QMqttTopicFilter
+    \inmodule QtMqtt
+    \reentrant
+    \ingroup shared
+
+    \brief The QMqttTopicFilter class represents a MQTT topic filter.
+
+    QMqttTopicFilter is a thin wrapper around a QString providing an expressive
+    data type for MQTT topic filters. Beside the benefits of having a strong
+    type preventing unintended misuse, QMqttTopicFilter provides convenient
+    functions related to topic filters like isValid() or match().
+
+    For example, the following code would fail to compile and prevent a possible
+    unintended and meaningless matching of two filters, especially if the
+    variable names were less expressive:
+
+    \code
+    QMqttTopicFilter globalFilter{"foo/#"};
+    QMqttTopicFilter specificFilter{"foo/bar"};
+    if (globalFilter.match(specificFilter)) {
+        //...
+    }
+    \endcode
+
+    The usability, however, is not affected since the following snippet compiles
+    and runs as expected:
+
+    \code
+    QMqttTopicFilter globalFilter{"foo/#"};
+    if (globalFilter.match("foo/bar")) {
+        //...
+    }
+    \endcode
+
+    \sa QMqttTopicName
+ */
+
+/*!
+    \fn void QMqttTopicFilter::swap(QMqttTopicFilter &other)
+    Swaps the MQTT topic filter \a other with this MQTT topic filter. This
+    operation is very fast and never fails.
+ */
+
+/*!
+    \enum QMqttTopicFilter::MatchOption
+
+    This enum value holds the matching options for the topic filter.
+
+    \value NoMatchOption
+        No match options are set.
+    \value WildcardsDontMatchDollarTopicMatchOption
+        A wildcard at the filter's beginning does not match a topic name that
+        starts with the dollar sign ($).
+ */
+
+class QMqttTopicFilterPrivate : public QSharedData
+{
+public:
+    QString filter;
+};
+
+/*!
+    Creates a new MQTT topic filter with the specified \a filter.
+ */
+QMqttTopicFilter::QMqttTopicFilter(const QString &filter) : d(new QMqttTopicFilterPrivate)
+{
+    d->filter = filter;
+}
+
+/*!
+    Creates a new MQTT topic filter with the specified \a filter.
+ */
+QMqttTopicFilter::QMqttTopicFilter(const QLatin1String &filter) : d(new QMqttTopicFilterPrivate)
+{
+    d->filter = filter;
+}
+
+/*!
+    Creates a new MQTT topic filter as a copy of \a filter.
+ */
+QMqttTopicFilter::QMqttTopicFilter(const QMqttTopicFilter &filter) : d(filter.d)
+{
+}
+
+/*!
+    Destroys the QMqttTopicFilter object.
+ */
+QMqttTopicFilter::~QMqttTopicFilter()
+{
+}
+
+/*!
+    Assigns the MQTT topic filter \a filter to this object, and returns a
+    reference to the copy.
+ */
+QMqttTopicFilter &QMqttTopicFilter::operator=(const QMqttTopicFilter &filter)
+{
+    d = filter.d;
+    return *this;
+}
+
+/*!
+    Returns the topic filter.
+ */
+QString QMqttTopicFilter::filter() const
+{
+    return d->filter;
+}
+
+/*!
+    Sets the topic filter to \a filter.
+ */
+void QMqttTopicFilter::setFilter(const QString &filter)
+{
+    d.detach();
+    d->filter = filter;
+}
+
+/*!
+    Returns \c true if the topic filter is valid according to the MQTT standard
+    section 4.7, or \c false otherwise.
+ */
+bool QMqttTopicFilter::isValid() const
+{
+    // MQTT-4.7.3-1, MQTT-4.7.3-3, and MQTT-4.7.3-2
+    const int size = d->filter.size();
+    if (size == 0 || size > 65535 || d->filter.contains(QChar(QChar::Null)))
+        return false;
+
+    if (size == 1)
+        return true;
+
+    // '#' MUST be last and its own level. It MUST NOT appear more than at most once.
+    const int multiLevelPosition = d->filter.indexOf(QLatin1Char('#'));
+    if (multiLevelPosition != -1
+        && (multiLevelPosition != size - 1 || d->filter.at(size-2) != QLatin1Char('/'))) {
+        return false;
+    }
+
+    // '+' MAY occur multiple times but MUST be its own level.
+    int singleLevelPosition = d->filter.indexOf(QLatin1Char('+'));
+    while (singleLevelPosition != -1) {
+        if ((singleLevelPosition != 0 && d->filter.at(singleLevelPosition - 1) != QLatin1Char('/'))
+            || (singleLevelPosition < size - 1 && d->filter.at(singleLevelPosition + 1) != QLatin1Char('/'))) {
+            return false;
+        }
+        singleLevelPosition = d->filter.indexOf(QLatin1Char('#'), singleLevelPosition + 1);
+    }
+
+    return true;
+}
+
+/*!
+    Returns \c true if the topic filter matches the topic name \a name
+    honoring the given \a matchOptions, or \c false otherwise.
+ */
+bool QMqttTopicFilter::match(const QMqttTopicName &name, MatchOptions matchOptions) const
+{
+    if (!name.isValid() || !isValid())
+        return false;
+
+    const QString topic = name.name();
+    if (topic == d->filter)
+        return true;
+
+    if (matchOptions.testFlag(WildcardsDontMatchDollarTopicMatchOption)
+        && topic.startsWith(QLatin1Char('$'))
+        && (d->filter.startsWith(QLatin1Char('+'))
+            || d->filter == QLatin1Char('#')
+            || d->filter == QLatin1String("/#"))) {
+        return false;
+    }
+
+    if (d->filter.endsWith(QLatin1Char('#'))) {
+        QStringRef root = d->filter.leftRef(d->filter.size() - 1);
+        if (root.endsWith(QLatin1Char('/'))) // '#' also represents the parent level!
+            root = root.left(root.size() - 1);
+        return topic.startsWith(root);
+    }
+
+    if (d->filter.contains(QLatin1Char('+'))) {
+        const QVector<QStringRef> filterLevels = d->filter.splitRef(QLatin1Char('/'));
+        const QVector<QStringRef> topicLevels = topic.splitRef(QLatin1Char('/'));
+        if (filterLevels.size() != topicLevels.size())
+            return false;
+        for (int i = 0; i < filterLevels.size(); ++i) {
+            const QStringRef &level = filterLevels.at(i);
+            if (level != QLatin1Char('+') && level != topicLevels.at(i))
+                return false;
+        }
+        return true;
+    }
+
+    return false;
+}
+
+/*!
+    \relates QMqttTopicFilter
+
+    Returns \c true if the topic filters \a lhs and \a rhs are equal,
+    otherwise returns \c false.
+ */
+bool operator==(const QMqttTopicFilter &lhs, const QMqttTopicFilter &rhs) Q_DECL_NOTHROW
+{
+    return (lhs.d == rhs.d) || (lhs.d->filter == rhs.d->filter);
+}
+
+/*!
+    \fn bool operator!=(const QMqttTopicFilter &lhs, const QMqttTopicFilter &rhs)
+    \relates QMqttTopicFilter
+
+    Returns \c true if the topic filters \a lhs and \a rhs are different,
+    otherwise returns \c false.
+ */
+
+/*!
+    \relates QMqttTopicFilter
+
+    Returns \c true if the topic filter \a lhs is lexically less than the topic
+    filter \a rhs; otherwise returns \c false.
+ */
+bool operator<(const QMqttTopicFilter &lhs, const QMqttTopicFilter &rhs) Q_DECL_NOTHROW
+{
+    return lhs.d->filter < rhs.d->filter;
+}
+
+/*!
+    \relates QHash
+
+    Returns the hash value for \a filter. If specified, \a seed is used to
+    initialize the hash.
+*/
+uint qHash(const QMqttTopicFilter &filter, uint seed) Q_DECL_NOTHROW
+{
+    return qHash(filter.d->filter, seed);
+}
+
+#ifndef QT_NO_DATASTREAM
+/*! \relates QMqttTopicFilter
+
+    Writes the topic filter \a filter to the stream \a out and returns a
+    reference to the stream.
+
+    \sa{Serializing Qt Data Types}{Format of the QDataStream operators}
+*/
+QDataStream &operator<<(QDataStream &out, const QMqttTopicFilter &filter)
+{
+    out << filter.filter();
+    return out;
+}
+
+/*! \relates QMqttTopicFilter
+
+    Reads a topic filter into \a filter from the stream \a in and returns a
+    reference to the stream.
+
+    \sa{Serializing Qt Data Types}{Format of the QDataStream operators}
+*/
+QDataStream &operator>>(QDataStream &in, QMqttTopicFilter &filter)
+{
+    QString f;
+    in >> f;
+    filter.setFilter(f);
+    return in;
+}
+#endif // QT_NO_DATASTREAM
+
+#ifndef QT_NO_DEBUG_STREAM
+QDebug operator<<(QDebug d, const QMqttTopicFilter &filter)
+{
+    QDebugStateSaver saver(d);
+    d.nospace() << "QMqttTopicFilter(" << filter.filter() << ')';
+    return d;
+}
+#endif
+
+QT_END_NAMESPACE
diff --git a/src/mqtt/qmqtttopicfilter.h b/src/mqtt/qmqtttopicfilter.h
new file mode 100644
index 0000000..8834a9a
--- /dev/null
+++ b/src/mqtt/qmqtttopicfilter.h
@@ -0,0 +1,101 @@
+/******************************************************************************
+**
+** Copyright (C) 2017 Lorenz Haas
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtMqtt module.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+******************************************************************************/
+
+#ifndef QMQTTTOPICFILTER_H
+#define QMQTTTOPICFILTER_H
+
+#include "qmqttglobal.h"
+
+#include <QtMqtt/QMqttTopicName>
+
+#include <QtCore/QExplicitlySharedDataPointer>
+#include <QtCore/QMetaType>
+#include <QtCore/QString>
+
+QT_BEGIN_NAMESPACE
+
+class QMqttTopicFilterPrivate;
+
+class QMqttTopicFilter;
+// qHash is a friend, but we can't use default arguments for friends (§8.3.6.4)
+Q_MQTT_EXPORT uint qHash(const QMqttTopicFilter &name, uint seed = 0) Q_DECL_NOTHROW;
+
+class Q_MQTT_EXPORT QMqttTopicFilter
+{
+public:
+    enum MatchOption {
+        NoMatchOption                            = 0x0000,
+        WildcardsDontMatchDollarTopicMatchOption = 0x0001
+    };
+    Q_DECLARE_FLAGS(MatchOptions, MatchOption)
+
+    QMqttTopicFilter(const QString &filter = QString());
+    QMqttTopicFilter(const QLatin1String &filter);
+    QMqttTopicFilter(const QMqttTopicFilter &filter);
+    ~QMqttTopicFilter();
+    QMqttTopicFilter &operator=(const QMqttTopicFilter &filter);
+
+#ifdef Q_COMPILER_RVALUE_REFS
+    inline QMqttTopicFilter &operator=(QMqttTopicFilter &&other) Q_DECL_NOTHROW { qSwap(d, other.d); return *this; }
+#endif
+
+    inline void swap(QMqttTopicFilter &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+
+    QString filter() const;
+    void setFilter(const QString &filter);
+
+    Q_REQUIRED_RESULT bool isValid() const;
+    Q_REQUIRED_RESULT bool match(const QMqttTopicName &name, MatchOptions matchOptions = NoMatchOption) const;
+
+    friend Q_MQTT_EXPORT bool operator==(const QMqttTopicFilter &lhs, const QMqttTopicFilter &rhs) Q_DECL_NOTHROW;
+    friend inline bool operator!=(const QMqttTopicFilter &lhs, const QMqttTopicFilter &rhs) Q_DECL_NOTHROW { return !(lhs == rhs); }
+    friend Q_MQTT_EXPORT bool operator<(const QMqttTopicFilter &lhs, const QMqttTopicFilter &rhs) Q_DECL_NOTHROW;
+    friend Q_MQTT_EXPORT uint qHash(const QMqttTopicFilter &filter, uint seed) Q_DECL_NOTHROW;
+
+private:
+    QExplicitlySharedDataPointer<QMqttTopicFilterPrivate> d;
+};
+
+Q_DECLARE_SHARED(QMqttTopicFilter)
+Q_DECLARE_OPERATORS_FOR_FLAGS(QMqttTopicFilter::MatchOptions)
+
+#ifndef QT_NO_DATASTREAM
+Q_MQTT_EXPORT QDataStream &operator<<(QDataStream &, const QMqttTopicFilter &);
+Q_MQTT_EXPORT QDataStream &operator>>(QDataStream &, QMqttTopicFilter &);
+#endif
+
+#ifndef QT_NO_DEBUG_STREAM
+Q_MQTT_EXPORT QDebug operator<<(QDebug, const QMqttTopicFilter &);
+#endif
+
+QT_END_NAMESPACE
+
+Q_DECLARE_METATYPE(QMqttTopicFilter)
+
+#endif // QMQTTTOPICFILTER_H
diff --git a/src/mqtt/qmqtttopicname.cpp b/src/mqtt/qmqtttopicname.cpp
new file mode 100644
index 0000000..d414db0
--- /dev/null
+++ b/src/mqtt/qmqtttopicname.cpp
@@ -0,0 +1,231 @@
+/******************************************************************************
+**
+** Copyright (C) 2017 Lorenz Haas
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtMqtt module.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+******************************************************************************/
+
+#include "qmqtttopicname.h"
+
+#include <QtCore/QDebug>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \class QMqttTopicName
+    \inmodule QtMqtt
+    \reentrant
+    \ingroup shared
+
+    \brief The QMqttTopicName class represents a MQTT topic name.
+
+    QMqttTopicName is a thin wrapper around a QString providing an expressive
+    data type for MQTT topic names. Beside the benefits of having a strong type
+    preventing unintended misuse, QMqttTopicName provides convenient functions
+    related to topic names like isValid() or levels().
+
+    \sa QMqttTopicFilter
+ */
+
+/*!
+    \fn void QMqttTopicName::swap(QMqttTopicName &other)
+    Swaps the MQTT topic name \a other with this MQTT topic name. This
+    operation is very fast and never fails.
+ */
+
+class QMqttTopicNamePrivate : public QSharedData
+{
+public:
+    QString name;
+};
+
+/*!
+    Creates a new MQTT topic name with the specified \a name.
+ */
+QMqttTopicName::QMqttTopicName(const QString &name) : d(new QMqttTopicNamePrivate)
+{
+    d->name = name;
+}
+
+/*!
+    Creates a new MQTT topic name with the specified \a name.
+ */
+QMqttTopicName::QMqttTopicName(const QLatin1String &name) : d(new QMqttTopicNamePrivate)
+{
+    d->name = name;
+}
+
+/*!
+    Creates a new MQTT topic name as a copy of \a name.
+ */
+QMqttTopicName::QMqttTopicName(const QMqttTopicName &name) : d(name.d)
+{
+}
+
+/*!
+    Destroys the QMqttTopicName object.
+ */
+QMqttTopicName::~QMqttTopicName()
+{
+}
+
+/*!
+    Assigns the MQTT topic name \a name to this object, and returns a reference
+    to the copy.
+ */
+QMqttTopicName &QMqttTopicName::operator=(const QMqttTopicName &name)
+{
+    d = name.d;
+    return *this;
+}
+
+/*!
+    Returns the topic name.
+ */
+QString QMqttTopicName::name() const
+{
+    return d->name;
+}
+
+/*!
+    Sets the topic name to \a name.
+ */
+void QMqttTopicName::setName(const QString &name)
+{
+    d.detach();
+    d->name = name;
+}
+
+/*!
+    Returns \c true if the topic name is valid according to the MQTT standard
+    section 4.7, or \c false otherwise.
+ */
+bool QMqttTopicName::isValid() const
+{
+    const int bytes = d->name.size();
+    return bytes > 0                                    // [MQTT-4.7.3-1]
+           && bytes < 65536                             // [MQTT-4.7.3-3]
+           && !d->name.contains(QLatin1Char('#'))       // [MQTT-4.7.1-1]
+           && !d->name.contains(QLatin1Char('+'))       // [MQTT-4.7.1-1]
+           && !d->name.contains(QChar(QChar::Null));    // [MQTT-4.7.3-2]
+}
+
+/*!
+    Returns the total number of topic levels.
+ */
+int QMqttTopicName::levelCount() const
+{
+    return d->name.isEmpty() ? 0 : d->name.count(QLatin1Char('/')) + 1;
+}
+
+/*!
+    Returns the topic levels.
+ */
+QStringList QMqttTopicName::levels() const
+{
+    return d->name.split(QLatin1Char('/'), QString::KeepEmptyParts);
+}
+
+/*!
+    \relates QMqttTopicName
+
+    Returns \c true if the topic names \a lhs and \a rhs are equal,
+    otherwise returns \c false.
+ */
+bool operator==(const QMqttTopicName &lhs, const QMqttTopicName &rhs) Q_DECL_NOTHROW
+{
+    return (lhs.d == rhs.d) || (lhs.d->name == rhs.d->name);
+}
+
+/*!
+    \fn bool operator!=(const QMqttTopicName &lhs, const QMqttTopicName &rhs)
+    \relates QMqttTopicName
+
+    Returns \c true if the topic names \a lhs and \a rhs are different,
+    otherwise returns \c false.
+ */
+
+/*!
+    \relates QMqttTopicName
+
+    Returns \c true if the topic name \a lhs is lexically less than the topic
+    name \a rhs; otherwise returns \c false.
+ */
+bool operator<(const QMqttTopicName &lhs, const QMqttTopicName &rhs) Q_DECL_NOTHROW
+{
+    return lhs.d->name < rhs.d->name;
+}
+
+/*!
+    \relates QHash
+
+    Returns the hash value for \a name. If specified, \a seed is used to
+    initialize the hash.
+*/
+uint qHash(const QMqttTopicName &name, uint seed) Q_DECL_NOTHROW
+{
+    return qHash(name.d->name, seed);
+}
+
+#ifndef QT_NO_DATASTREAM
+/*! \relates QMqttTopicName
+
+    Writes the topic name \a name to the stream \a out and returns a reference
+    to the stream.
+
+    \sa{Serializing Qt Data Types}{Format of the QDataStream operators}
+*/
+QDataStream &operator<<(QDataStream &out, const QMqttTopicName &name)
+{
+    out << name.name();
+    return out;
+}
+
+/*! \relates QMqttTopicName
+
+    Reads a topic name into \a name from the stream \a in and returns a
+    reference to the stream.
+
+    \sa{Serializing Qt Data Types}{Format of the QDataStream operators}
+*/
+QDataStream &operator>>(QDataStream &in, QMqttTopicName &name)
+{
+    QString n;
+    in >> n;
+    name.setName(n);
+    return in;
+}
+#endif // QT_NO_DATASTREAM
+
+#ifndef QT_NO_DEBUG_STREAM
+QDebug operator<<(QDebug d, const QMqttTopicName &name)
+{
+    QDebugStateSaver saver(d);
+    d.nospace() << "QMqttTopicName(" << name.name() << ')';
+    return d;
+}
+#endif
+
+QT_END_NAMESPACE
diff --git a/src/mqtt/qmqtttopicname.h b/src/mqtt/qmqtttopicname.h
new file mode 100644
index 0000000..09898bf
--- /dev/null
+++ b/src/mqtt/qmqtttopicname.h
@@ -0,0 +1,94 @@
+/******************************************************************************
+**
+** Copyright (C) 2017 Lorenz Haas
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtMqtt module.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+******************************************************************************/
+
+#ifndef QMQTTTOPICNAME_H
+#define QMQTTTOPICNAME_H
+
+#include "qmqttglobal.h"
+
+#include <QtCore/QExplicitlySharedDataPointer>
+#include <QtCore/QMetaType>
+#include <QtCore/QString>
+#include <QtCore/QStringList>
+
+QT_BEGIN_NAMESPACE
+
+class QMqttTopicNamePrivate;
+
+class QMqttTopicName;
+// qHash is a friend, but we can't use default arguments for friends (§8.3.6.4)
+Q_MQTT_EXPORT uint qHash(const QMqttTopicName &name, uint seed = 0) Q_DECL_NOTHROW;
+
+class Q_MQTT_EXPORT QMqttTopicName
+{
+public:
+    QMqttTopicName(const QString &name = QString());
+    QMqttTopicName(const QLatin1String &name);
+    QMqttTopicName(const QMqttTopicName &name);
+    ~QMqttTopicName();
+    QMqttTopicName &operator=(const QMqttTopicName &name);
+
+#ifdef Q_COMPILER_RVALUE_REFS
+    inline QMqttTopicName &operator=(QMqttTopicName &&other) Q_DECL_NOTHROW { qSwap(d, other.d); return *this; }
+#endif
+
+    inline void swap(QMqttTopicName &other) Q_DECL_NOTHROW { qSwap(d, other.d); }
+
+    QString name() const;
+    void setName(const QString &name);
+
+    Q_REQUIRED_RESULT bool isValid() const;
+    Q_REQUIRED_RESULT int levelCount() const;
+    Q_REQUIRED_RESULT QStringList levels() const;
+
+    friend Q_MQTT_EXPORT bool operator==(const QMqttTopicName &lhs, const QMqttTopicName &rhs) Q_DECL_NOTHROW;
+    friend inline bool operator!=(const QMqttTopicName &lhs, const QMqttTopicName &rhs) Q_DECL_NOTHROW { return !(lhs == rhs); }
+    friend Q_MQTT_EXPORT bool operator<(const QMqttTopicName &lhs, const QMqttTopicName &rhs) Q_DECL_NOTHROW;
+    friend Q_MQTT_EXPORT uint qHash(const QMqttTopicName &name, uint seed) Q_DECL_NOTHROW;
+
+private:
+    QExplicitlySharedDataPointer<QMqttTopicNamePrivate> d;
+};
+
+Q_DECLARE_SHARED(QMqttTopicName)
+
+#ifndef QT_NO_DATASTREAM
+Q_MQTT_EXPORT QDataStream &operator<<(QDataStream &, const QMqttTopicName &);
+Q_MQTT_EXPORT QDataStream &operator>>(QDataStream &, QMqttTopicName &);
+#endif
+
+#ifndef QT_NO_DEBUG_STREAM
+Q_MQTT_EXPORT QDebug operator<<(QDebug, const QMqttTopicName &);
+#endif
+
+QT_END_NAMESPACE
+
+Q_DECLARE_METATYPE(QMqttTopicName)
+
+#endif // QMQTTTOPICNAME_H
diff --git a/sync.profile b/sync.profile
index 77d0e2e..a9e8018 100644
--- a/sync.profile
+++ b/sync.profile
@@ -3,5 +3,5 @@
 );
 
 %dependencies = (
-        "qtbase" => ""
+        "qtbase" => "",
 );
diff --git a/tests/README.txt b/tests/README.txt
new file mode 100644
index 0000000..3a8bf51
--- /dev/null
+++ b/tests/README.txt
@@ -0,0 +1,21 @@
+The tests included in the subdirectories check for functionality and
+conformance of the Qt MQTT module.
+
+To be able to run the tests successfully, a broker needs to be available and
+reachable.
+
+The continuous integration utilized the paho conformance test broker. It can
+be obtained at this location:
+https://github.com/eclipse/paho.mqtt.testing
+
+For the unit tests being able to locate this script, use the
+MQTT_TEST_BROKER_LOCATION environment variable and set it
+to “<install-path>/interoperability/startbroker.py”.
+
+Alternatively, any broker can be instantiated and passed to the auto tests
+by using the environment variable MQTT_TEST_BROKER. This must point to a
+valid url. The broker must run on the standardized port 1883.
+
+Note, that the unit tests verify functionality against the MQTT 3.1.1 version
+of the standard, hence the broker needs to be compliant to the adherent
+specifications.
diff --git a/tests/auto/auto.pro b/tests/auto/auto.pro
index dfa905c..ecd1207 100644
--- a/tests/auto/auto.pro
+++ b/tests/auto/auto.pro
@@ -4,4 +4,6 @@ win32|if(linux:!cross_compile): SUBDIRS += cmake \
                                       conformance \
                                       qmqttcontrolpacket \
                                       qmqttclient \
-                                      qmqttsubscription
+                                      qmqttsubscription \
+                                      qmqtttopicname \
+                                      qmqtttopicfilter
diff --git a/tests/auto/conformance/tst_conformance.cpp b/tests/auto/conformance/tst_conformance.cpp
index c748fb9..ca3cc61 100644
--- a/tests/auto/conformance/tst_conformance.cpp
+++ b/tests/auto/conformance/tst_conformance.cpp
@@ -274,15 +274,15 @@ void Tst_MqttConformance::offline_message_queueing_test()
     QTRY_VERIFY2(publisher.state() == QMqttClient::Connected, "Could not connect to broker.");
 
     QSignalSpy pubCounter(&publisher, SIGNAL(messageSent(qint32)));
-    publisher.publish("Qt/offline/foo/bar", "msg1", 1);
-    publisher.publish("Qt/offline/foo/bar2", "msg2", 1);
-    publisher.publish("Qt/offline/foo2/bar", "msg3", 1);
+    publisher.publish(QLatin1String("Qt/offline/foo/bar"), "msg1", 1);
+    publisher.publish(QLatin1String("Qt/offline/foo/bar2"), "msg2", 1);
+    publisher.publish(QLatin1String("Qt/offline/foo2/bar"), "msg3", 1);
     QTRY_VERIFY2(pubCounter.size() == 3, "Could not publish all messages.");
 
     publisher.disconnectFromHost();
     QTRY_VERIFY2(publisher.state() == QMqttClient::Disconnected, "Could not disconnect.");
 
-    QSignalSpy receiveCounter(&client, SIGNAL(messageReceived(QByteArray,QString)));
+    QSignalSpy receiveCounter(&client, SIGNAL(messageReceived(QByteArray,QMqttTopicName)));
 
     client.connectToHost();
     QTRY_VERIFY2(client.state() == QMqttClient::Connected, "Could not connect to broker.");
@@ -306,7 +306,7 @@ void Tst_MqttConformance::subscribe_failure_test()
     client.connectToHost();
     QTRY_VERIFY2(client.state() == QMqttClient::Connected, "Could not connect to broker.");
 
-    auto sub = client.subscribe(forbiddenTopic, 1);
+    auto sub = client.subscribe(QMqttTopicFilter(forbiddenTopic), 1);
     QVERIFY2(sub->state() == QMqttSubscription::SubscriptionPending, "Could not initiate subscription");
 
     QTRY_VERIFY2(sub->state() == QMqttSubscription::Error, "Did not receive error state for sub.");
diff --git a/tests/auto/qmqttclient/tst_qmqttclient.cpp b/tests/auto/qmqttclient/tst_qmqttclient.cpp
index 58290e4..6c70007 100644
--- a/tests/auto/qmqttclient/tst_qmqttclient.cpp
+++ b/tests/auto/qmqttclient/tst_qmqttclient.cpp
@@ -29,6 +29,7 @@
 #include "broker_connection.h"
 
 #include <QtCore/QString>
+#include <QtNetwork/QTcpServer>
 #include <QtTest/QtTest>
 #include <QtTest/QSignalSpy>
 #include <QtMqtt/QMqttClient>
@@ -50,9 +51,12 @@ private Q_SLOTS:
     void sendReceive();
     void retainMessage();
     void willMessage();
-    void longTopic_data();
-    void longTopic();
+    void compliantTopic_data();
+    void compliantTopic();
     void subscribeLongTopic();
+    void dataIncludingZero();
+    void publishLongTopic();
+    void reconnect_QTBUG65726();
 private:
     QProcess m_brokerProcess;
     QString m_testBroker;
@@ -201,7 +205,7 @@ void Tst_QMqttClient::retainMessage()
                 msgCount++;
         });
 
-        QSignalSpy messageSpy(&sub, SIGNAL(messageReceived(QByteArray,QString)));
+        QSignalSpy messageSpy(&sub, SIGNAL(messageReceived(QByteArray,QMqttTopicName)));
         sub.connectToHost();
         QTRY_COMPARE(sub.state(), QMqttClient::Connected);
 
@@ -270,7 +274,7 @@ void Tst_QMqttClient::willMessage()
     }
 }
 
-void Tst_QMqttClient::longTopic_data()
+void Tst_QMqttClient::compliantTopic_data()
 {
     QTest::addColumn<QString>("topic");
     QTest::newRow("simple") << QString::fromLatin1("topic");
@@ -279,11 +283,9 @@ void Tst_QMqttClient::longTopic_data()
     QString l;
     l.fill(QLatin1Char('T'), std::numeric_limits<std::uint16_t>::max());
     QTest::newRow("maxSize") << l;
-    l.fill(QLatin1Char('M'), 2 * std::numeric_limits<std::uint16_t>::max());
-    QTest::newRow("overflow") << l;
 }
 
-void Tst_QMqttClient::longTopic()
+void Tst_QMqttClient::compliantTopic()
 {
     QFETCH(QString, topic);
     QString truncTopic = topic;
@@ -307,7 +309,7 @@ void Tst_QMqttClient::longTopic()
 
     bool received = false;
     bool verified = false;
-    connect(&subscriber, &QMqttClient::messageReceived, [&](const QByteArray &, const QString &t) {
+    connect(&subscriber, &QMqttClient::messageReceived, [&](const QByteArray &, const QMqttTopicName &t) {
         received = true;
         verified = t == truncTopic;
     });
@@ -337,6 +339,114 @@ void Tst_QMqttClient::subscribeLongTopic()
     QCOMPARE(sub, nullptr);
 }
 
+void Tst_QMqttClient::dataIncludingZero()
+{
+    QByteArray data;
+    const int dataSize = 200;
+    data.fill('A', dataSize);
+    data[100] = '\0';
+
+    QMqttClient client;
+    client.setHostname(m_testBroker);
+    client.setPort(m_port);
+
+    client.connectToHost();
+    QTRY_COMPARE(client.state(), QMqttClient::Connected);
+
+    bool received = false;
+    bool verified = false;
+    bool correctSize = false;
+    const QString testTopic(QLatin1String("some/topic"));
+    auto sub = client.subscribe(testTopic, 1);
+    QVERIFY(sub);
+    connect(sub, &QMqttSubscription::messageReceived, [&](QMqttMessage msg) {
+        verified = msg.payload() == data;
+        correctSize = msg.payload().size() == dataSize;
+        received = true;
+    });
+
+    QTRY_COMPARE(sub->state(), QMqttSubscription::Subscribed);
+
+    client.publish(testTopic, data, 1);
+
+    QTRY_VERIFY2(received, "Subscriber did not receive message");
+    QVERIFY2(verified, "Subscriber received different message");
+    QVERIFY2(correctSize, "Subscriber received message of different size");
+}
+
+void Tst_QMqttClient::publishLongTopic()
+{
+    QMqttClient publisher;
+    publisher.setClientId(QLatin1String("publisher"));
+    publisher.setHostname(m_testBroker);
+    publisher.setPort(m_port);
+
+    publisher.connectToHost();
+    QTRY_COMPARE(publisher.state(), QMqttClient::Connected);
+
+    QString topic;
+    topic.fill(QLatin1Char('s'), 2 * std::numeric_limits<std::uint16_t>::max());
+    auto pub = publisher.publish(topic);
+    QCOMPARE(pub, -1);
+}
+
+class FakeServer : public QObject
+{
+    Q_OBJECT
+public:
+    FakeServer() {
+        server = new QTcpServer();
+        connect(server, &QTcpServer::newConnection, this, &FakeServer::createSocket);
+        server->listen(QHostAddress::Any, 5726);
+    }
+public slots:
+    void createSocket() {
+        socket = server->nextPendingConnection();
+        connect(socket, &QTcpSocket::readyRead, this, &FakeServer::connectionRequested);
+    }
+
+    void connectionRequested() {
+        // We assume it is always a connect statement, so no verification is done
+        socket->readAll();
+        QByteArray response;
+        response += 0x20;
+        response += quint8(2); // Payload size
+        if (!connectionSuccess) {
+            response += quint8(255); // Causes ProtocolViolation
+            response += quint8(13);
+        } else {
+            response += char(0); // ackFlags
+            response += char(0); // result
+        }
+        qDebug() << "Fake server response:" << connectionSuccess;
+        socket->write(response);
+    }
+public:
+    QTcpServer *server;
+    QTcpSocket *socket;
+    bool connectionSuccess{false};
+};
+
+void Tst_QMqttClient::reconnect_QTBUG65726()
+{
+    FakeServer server;
+
+    QMqttClient client;
+    client.setClientId(QLatin1String("bugclient"));
+    client.setHostname(QLatin1String("localhost"));
+    client.setPort(5726);
+
+    client.connectToHost();
+    QTRY_COMPARE(client.state(), QMqttClient::Disconnected);
+    QTRY_COMPARE(client.error(), QMqttClient::ProtocolViolation);
+
+    server.connectionSuccess = true;
+
+    client.connectToHost();
+    QTRY_COMPARE(client.state(), QMqttClient::Connected);
+    QTRY_COMPARE(client.error(), QMqttClient::NoError);
+}
+
 QTEST_MAIN(Tst_QMqttClient)
 
 #include "tst_qmqttclient.moc"
diff --git a/tests/auto/qmqttcontrolpacket/tst_qmqttcontrolpacket.cpp b/tests/auto/qmqttcontrolpacket/tst_qmqttcontrolpacket.cpp
index 7a0827d..de0e404 100644
--- a/tests/auto/qmqttcontrolpacket/tst_qmqttcontrolpacket.cpp
+++ b/tests/auto/qmqttcontrolpacket/tst_qmqttcontrolpacket.cpp
@@ -123,6 +123,19 @@ void Tst_QMqttControlPacket::append()
     payload = packet.payload();
     QCOMPARE(payload.size(), data.size());
     QCOMPARE(payload, data);
+
+    const QByteArray containsZero("Some data\0 with zero", 21);
+    packet.clear();
+    packet.appendRaw(containsZero);
+    payload = packet.payload();
+    QCOMPARE(containsZero, payload);
+    QCOMPARE(payload.size(), 21);
+
+    packet.clear();
+    packet.append(containsZero);
+    payload = packet.payload().mid(2); // mid because size got prepended
+    QCOMPARE(containsZero, payload);
+    QCOMPARE(payload.size(), 21);
 #else
     QSKIP("This test requires a Qt -developer-build.");
 #endif
diff --git a/tests/auto/qmqttsubscription/tst_qmqttsubscription.cpp b/tests/auto/qmqttsubscription/tst_qmqttsubscription.cpp
index 7f51dd5..fda8ef6 100644
--- a/tests/auto/qmqttsubscription/tst_qmqttsubscription.cpp
+++ b/tests/auto/qmqttsubscription/tst_qmqttsubscription.cpp
@@ -47,6 +47,7 @@ private Q_SLOTS:
     void getSetCheck();
     void wildCards_data();
     void wildCards();
+    void reconnect();
 private:
     QProcess m_brokerProcess;
     QString m_testBroker;
@@ -141,6 +142,81 @@ void Tst_QMqttSubscription::wildCards()
     QTRY_VERIFY2(publisher.state() == QMqttClient::Disconnected, "Could not disconnect.");
 }
 
+void Tst_QMqttSubscription::reconnect()
+{
+    // QTBUG-64042
+    //    - Connect with clean session
+    QMqttClient client;
+
+    client.setHostname(m_testBroker);
+    client.setPort(m_port);
+    client.setCleanSession(true);
+    client.connectToHost();
+    QTRY_VERIFY2(client.state() == QMqttClient::Connected, "Could not connect to broker.");
+
+    //    - Subscribe to topic A
+    const QString subscription("topics/resub");
+    auto sub = client.subscribe(subscription, 1);
+    QTRY_VERIFY2(sub->state() == QMqttSubscription::Subscribed, "Could not subscribe to topic.");
+
+    //    - Loose connection / connection drop
+    QAbstractSocket *transport = qobject_cast<QAbstractSocket *>(client.transport());
+    QVERIFY2(transport, "Transport has to be QAbstractSocket-based.");
+    transport->disconnectFromHost();
+    QTRY_VERIFY2(client.state() == QMqttClient::Disconnected, "State not correctly switched.");
+
+    //    - Reconnect (keeping cleansession)
+    client.connectToHost();
+    QTRY_VERIFY2(client.state() == QMqttClient::Connected, "Could not connect to broker.");
+    // old subs should get updated / invalidated
+    QCOMPARE(sub->state(), QMqttSubscription::Unsubscribed);
+
+    //    - Resubscribe
+    auto reSub = client.subscribe(subscription, 1);
+    QTRY_VERIFY2(reSub->state() == QMqttSubscription::Subscribed, "Could not re-subscribe to topic.");
+    QSignalSpy receivalSpy(reSub, SIGNAL(messageReceived(QMqttMessage)));
+
+    QSignalSpy pubSpy(&client, SIGNAL(messageSent(qint32)));
+    client.publish(subscription, "Sending after reconnect 1", 1);
+    QTRY_VERIFY2(pubSpy.size() == 1, "Could not publish message.");
+
+    QTRY_VERIFY2(receivalSpy.size() == 1, "Did not receive message on re-subscribe.");
+
+    //    - Loose connection / connection drop
+    transport = qobject_cast<QAbstractSocket *>(client.transport());
+    QVERIFY2(transport, "Transport has to be QAbstractSocket-based.");
+    transport->disconnectFromHost();
+    QTRY_VERIFY2(client.state() == QMqttClient::Disconnected, "State not correctly switched.");
+
+    //    - Reconnect (no cleansession)
+    QSignalSpy restoredSpy(&client, SIGNAL(brokerSessionRestored()));
+
+    client.setCleanSession(false);
+    client.connectToHost();
+    QTRY_VERIFY2(client.state() == QMqttClient::Connected, "Could not connect to broker.");
+    // Could not identify a broker doing this. The specs states:
+    // [MQTT-4.1.0-1] The Client and Server MUST store Session state for the entire
+    //                duration of the Session.
+    // [MQTT-4.1.0-2] A Session MUST last at least as long it has an active Network Connection.
+    // All testbrokers delete the session at transport disconnect, regardless of DISCONNECT been
+    // send before or not.
+    if (restoredSpy.count() > 0) {
+        QCOMPARE(reSub->state(), QMqttSubscription::Subscribed);
+        pubSpy.clear();
+        receivalSpy.clear();
+        client.publish(subscription, "Sending after reconnect 2", 1);
+        QTRY_VERIFY2(pubSpy.size() == 1, "Could not publish message.");
+        QTRY_VERIFY2(receivalSpy.size() == 1, "Did not receive message on re-subscribe.");
+    } else {
+        // No need to test this
+        qDebug() << "Test broker does not support long-livety sessions.";
+    }
+    //    - Old subscription is still active
+
+    client.disconnectFromHost();
+    QTRY_VERIFY2(client.state() == QMqttClient::Disconnected, "Could not disconnect.");
+}
+
 QTEST_MAIN(Tst_QMqttSubscription)
 
 #include "tst_qmqttsubscription.moc"
diff --git a/tests/auto/qmqtttopicfilter/qmqtttopicfilter.pro b/tests/auto/qmqtttopicfilter/qmqtttopicfilter.pro
new file mode 100644
index 0000000..3ce2d77
--- /dev/null
+++ b/tests/auto/qmqtttopicfilter/qmqtttopicfilter.pro
@@ -0,0 +1,11 @@
+CONFIG += testcase
+QT       += testlib mqtt
+QT       -= gui
+QT_PRIVATE += mqtt-private
+
+TARGET = tst_qmqtttopicfilter
+
+SOURCES += \
+    tst_qmqtttopicfilter.cpp
+
+DEFINES += SRCDIR=\\\"$$PWD/\\\"
diff --git a/tests/auto/qmqtttopicfilter/tst_qmqtttopicfilter.cpp b/tests/auto/qmqtttopicfilter/tst_qmqtttopicfilter.cpp
new file mode 100644
index 0000000..f83999c
--- /dev/null
+++ b/tests/auto/qmqtttopicfilter/tst_qmqtttopicfilter.cpp
@@ -0,0 +1,144 @@
+/******************************************************************************
+**
+** Copyright (C) 2017 Lorenz Haas
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtMqtt module.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+******************************************************************************/
+
+#include <QtCore/QHash>
+#include <QtCore/QMap>
+#include <QtCore/QVector>
+#include <QtMqtt/QMqttTopicFilter>
+#include <QtTest/QtTest>
+
+class Tst_QMqttTopicFilter : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void checkValidity();
+    void matches();
+
+    void usableWithQVector();
+    void usableWithQMap();
+    void usableWithQHash();
+};
+
+void Tst_QMqttTopicFilter::checkValidity()
+{
+    QVERIFY(QMqttTopicFilter("a").isValid());
+    QVERIFY(QMqttTopicFilter("/").isValid());
+    QVERIFY(QMqttTopicFilter("a b").isValid());
+    QVERIFY(QMqttTopicFilter("#").isValid());
+    QVERIFY(QMqttTopicFilter("/#").isValid());
+    QVERIFY(QMqttTopicFilter("a/#").isValid());
+    QVERIFY(QMqttTopicFilter("/a/#").isValid());
+    QVERIFY(QMqttTopicFilter("+").isValid());
+    QVERIFY(QMqttTopicFilter("/+").isValid());
+    QVERIFY(QMqttTopicFilter("+/").isValid());
+    QVERIFY(QMqttTopicFilter("/+/").isValid());
+    QVERIFY(QMqttTopicFilter("/+/+").isValid());
+    QVERIFY(QMqttTopicFilter("+/#").isValid());
+    QVERIFY(QMqttTopicFilter("a/+/b").isValid());
+
+    QVERIFY(!QMqttTopicFilter("").isValid());
+    QVERIFY(!QMqttTopicFilter("#/").isValid());
+    QVERIFY(!QMqttTopicFilter("/a/#/").isValid());
+    QVERIFY(!QMqttTopicFilter("#/#").isValid());
+    QVERIFY(!QMqttTopicFilter("a#").isValid());
+    QVERIFY(!QMqttTopicFilter("/a#").isValid());
+
+    QVERIFY(!QMqttTopicFilter("a+").isValid());
+    QVERIFY(!QMqttTopicFilter("+a").isValid());
+    QVERIFY(!QMqttTopicFilter("++").isValid());
+
+    QVERIFY(!QMqttTopicFilter(QString(3, QChar(QChar::Null))).isValid());
+}
+
+void Tst_QMqttTopicFilter::matches()
+{
+    // Non normative comment's examples [4.7.1.2]
+    QMqttTopicFilter filter("sport/tennis/player1/#");
+    QVERIFY(filter.match(QMqttTopicName("sport/tennis/player1")));
+    QVERIFY(filter.match(QMqttTopicName("sport/tennis/player1/ranking")));
+    QVERIFY(filter.match(QMqttTopicName("sport/tennis/player1/score/wimbledon")));
+
+    filter = QMqttTopicFilter("sport/#");
+    QVERIFY(filter.match(QMqttTopicName("sport")));
+
+    // Non normative comment's examples [4.7.1.3]
+    filter = QMqttTopicFilter("sport/tennis/+");
+    QVERIFY(filter.match(QMqttTopicName("sport/tennis/player1")));
+    QVERIFY(!filter.match(QMqttTopicName("sport/tennis/player1/ranking")));
+
+    filter = QMqttTopicFilter("sport/+");
+    QVERIFY(filter.match(QMqttTopicName("sport/")));
+    QVERIFY(!filter.match(QMqttTopicName("sport")));
+
+    QVERIFY(QMqttTopicFilter("+/+").match(QMqttTopicName("/finance")));
+    QVERIFY(QMqttTopicFilter("/+").match(QMqttTopicName("/finance")));
+    QVERIFY(!QMqttTopicFilter("+").match(QMqttTopicName("/finance")));
+
+    // Non normative comment's examples [4.7.2]
+    QVERIFY(QMqttTopicFilter("#").match(QMqttTopicName("$SYS/foo")));
+    QVERIFY(!QMqttTopicFilter("#").match(QMqttTopicName("$SYS/foo"), QMqttTopicFilter::WildcardsDontMatchDollarTopicMatchOption));
+
+    QVERIFY(QMqttTopicFilter("+/monitor/Clients").match(QMqttTopicName("$SYS/monitor/Clients")));
+    QVERIFY(!QMqttTopicFilter("+/monitor/Clients").match(QMqttTopicName("$SYS/monitor/Clients"), QMqttTopicFilter::WildcardsDontMatchDollarTopicMatchOption));
+
+    QVERIFY(QMqttTopicFilter("$SYS/#").match(QMqttTopicName("$SYS/foo")));
+    QVERIFY(QMqttTopicFilter("$SYS/#").match(QMqttTopicName("$SYS/foo"), QMqttTopicFilter::WildcardsDontMatchDollarTopicMatchOption));
+
+    QVERIFY(QMqttTopicFilter("$SYS/monitor/+").match(QMqttTopicName("$SYS/monitor/Clients")));
+    QVERIFY(QMqttTopicFilter("$SYS/monitor/+").match(QMqttTopicName("$SYS/monitor/Clients"), QMqttTopicFilter::WildcardsDontMatchDollarTopicMatchOption));
+}
+
+void Tst_QMqttTopicFilter::usableWithQVector()
+{
+    const QMqttTopicFilter topic{"a/b"};
+    QVector<QMqttTopicFilter> names;
+    names.append(topic);
+    QCOMPARE(topic, names.constFirst());
+}
+
+void Tst_QMqttTopicFilter::usableWithQMap()
+{
+    const QMqttTopicFilter topic{"a/b"};
+    QMap<QMqttTopicFilter, int> names;
+    names.insert(topic, 42);
+    QCOMPARE(names[topic], 42);
+}
+
+void Tst_QMqttTopicFilter::usableWithQHash()
+{
+    const QMqttTopicFilter topic{"a/b"};
+    QHash<QMqttTopicFilter, int> names;
+    names.insert(topic, 42);
+    QCOMPARE(names[topic], 42);
+}
+
+QTEST_MAIN(Tst_QMqttTopicFilter)
+
+#include "tst_qmqtttopicfilter.moc"
diff --git a/tests/auto/qmqtttopicname/qmqtttopicname.pro b/tests/auto/qmqtttopicname/qmqtttopicname.pro
new file mode 100644
index 0000000..30d7d05
--- /dev/null
+++ b/tests/auto/qmqtttopicname/qmqtttopicname.pro
@@ -0,0 +1,11 @@
+CONFIG += testcase
+QT       += testlib mqtt
+QT       -= gui
+QT_PRIVATE += mqtt-private
+
+TARGET = tst_qmqtttopicname
+
+SOURCES += \
+    tst_qmqtttopicname.cpp
+
+DEFINES += SRCDIR=\\\"$$PWD/\\\"
diff --git a/tests/auto/qmqtttopicname/tst_qmqtttopicname.cpp b/tests/auto/qmqtttopicname/tst_qmqtttopicname.cpp
new file mode 100644
index 0000000..6f33e8c
--- /dev/null
+++ b/tests/auto/qmqtttopicname/tst_qmqtttopicname.cpp
@@ -0,0 +1,121 @@
+/******************************************************************************
+**
+** Copyright (C) 2017 Lorenz Haas
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtMqtt module.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+******************************************************************************/
+
+#include <QtCore/QHash>
+#include <QtCore/QMap>
+#include <QtCore/QVector>
+#include <QtMqtt/QMqttTopicName>
+#include <QtTest/QtTest>
+
+class Tst_QMqttTopicName : public QObject
+{
+    Q_OBJECT
+
+private Q_SLOTS:
+    void checkValidity();
+    void checkLevelCount();
+    void checkLevels_data();
+    void checkLevels();
+    void usableWithQVector();
+    void usableWithQMap();
+    void usableWithQHash();
+};
+
+void Tst_QMqttTopicName::checkValidity()
+{
+    QVERIFY(QMqttTopicName("a").isValid());
+    QVERIFY(QMqttTopicName("/").isValid());
+    QVERIFY(QMqttTopicName("a b").isValid());
+
+    QVERIFY(!QMqttTopicName("").isValid());
+    QVERIFY(!QMqttTopicName("/a/#").isValid());
+    QVERIFY(!QMqttTopicName("/+/a").isValid());
+    QVERIFY(!QMqttTopicName(QString(3, QChar(QChar::Null))).isValid());
+}
+
+void Tst_QMqttTopicName::checkLevelCount()
+{
+    QCOMPARE(QMqttTopicName("a").levelCount(), 1);
+    QCOMPARE(QMqttTopicName("/").levelCount(), 2);
+    QCOMPARE(QMqttTopicName("/a").levelCount(), 2);
+    QCOMPARE(QMqttTopicName("a/").levelCount(), 2);
+    QCOMPARE(QMqttTopicName("a/b").levelCount(), 2);
+    QCOMPARE(QMqttTopicName("a/b/").levelCount(), 3);
+}
+
+void Tst_QMqttTopicName::checkLevels_data()
+{
+    QTest::addColumn<QMqttTopicName>("name");
+    QTest::addColumn<QStringList>("levels");
+
+    QTest::newRow("1") << QMqttTopicName("a") << QStringList{"a"};
+    QTest::newRow("2") << QMqttTopicName("/") << QStringList{"", ""};
+    QTest::newRow("3") << QMqttTopicName("//") << QStringList{"", "", ""};
+    QTest::newRow("4") << QMqttTopicName("a/") << QStringList{"a", ""};
+    QTest::newRow("5") << QMqttTopicName("/a") << QStringList{"", "a"};
+    QTest::newRow("6") << QMqttTopicName("a/b") << QStringList{"a", "b"};
+    QTest::newRow("7") << QMqttTopicName("a/b/") << QStringList{"a", "b", ""};
+    QTest::newRow("8") << QMqttTopicName("/a/b") << QStringList{"", "a", "b"};
+}
+
+void Tst_QMqttTopicName::checkLevels()
+{
+    QFETCH(QMqttTopicName, name);
+    QFETCH(QStringList, levels);
+
+    QCOMPARE(name.levels(), levels);
+}
+
+void Tst_QMqttTopicName::usableWithQVector()
+{
+    const QMqttTopicName topic{"a/b"};
+    QVector<QMqttTopicName> names;
+    names.append(topic);
+    QCOMPARE(topic, names.constFirst());
+}
+
+void Tst_QMqttTopicName::usableWithQMap()
+{
+    const QMqttTopicName topic{"a/b"};
+    QMap<QMqttTopicName, int> names;
+    names.insert(topic, 42);
+    QCOMPARE(names[topic], 42);
+}
+
+void Tst_QMqttTopicName::usableWithQHash()
+{
+    const QMqttTopicName topic{"a/b"};
+    QHash<QMqttTopicName, int> names;
+    names.insert(topic, 42);
+    QCOMPARE(names[topic], 42);
+}
+
+QTEST_MAIN(Tst_QMqttTopicName)
+
+#include "tst_qmqtttopicname.moc"