Disallow property changes while connected

Certain properties cannot be changed while connected and hence this
should be reflected in the behavior.

Task-number: QTBUG-67176
Change-Id: Ib9baafa1ac8d99d7a071839c892187efb51491e0
Reviewed-by: hjk <hjk@qt.io>

src/mqtt/qmqttclient.cpp

@@ -580,6 +580,12 @@ quint16 QMqttClient::keepAlive() const
 void QMqttClient::setHostname(const QString &hostname)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing hostname while connected is not possible.";
+        return;
+    }
+
     if (d->m_hostname == hostname)
         return;
 
@@ -590,6 +596,12 @@ void QMqttClient::setHostname(const QString &hostname)
 void QMqttClient::setPort(quint16 port)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing port while connected is not possible.";
+        return;
+    }
+
     if (d->m_port == port)
         return;
 
@@ -600,11 +612,12 @@ void QMqttClient::setPort(quint16 port)
 void QMqttClient::setClientId(const QString &clientId)
 {
     Q_D(QMqttClient);
-    if (d->m_clientId == clientId)
-        return;
 
-    d->m_clientId = clientId;
-    emit clientIdChanged(clientId);
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing client ID while connected is not possible.";
+        return;
+    }
+    d->setClientId(clientId);
 }
 
 void QMqttClient::setKeepAlive(quint16 keepAlive)
@@ -625,6 +638,12 @@ void QMqttClient::setKeepAlive(quint16 keepAlive)
 void QMqttClient::setProtocolVersion(ProtocolVersion protocolVersion)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing protocol version while connected is not possible.";
+        return;
+    }
+
     if (d->m_protocolVersion == protocolVersion)
         return;
 
@@ -652,6 +671,12 @@ void QMqttClient::setState(ClientState state)
 void QMqttClient::setUsername(const QString &username)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing username while connected is not possible.";
+        return;
+    }
+
     if (d->m_username == username)
         return;
 
@@ -662,6 +687,12 @@ void QMqttClient::setUsername(const QString &username)
 void QMqttClient::setPassword(const QString &password)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing password while connected is not possible.";
+        return;
+    }
+
     if (d->m_password == password)
         return;
 
@@ -672,6 +703,12 @@ void QMqttClient::setPassword(const QString &password)
 void QMqttClient::setCleanSession(bool cleanSession)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing clean session while connected is not possible.";
+        return;
+    }
+
     if (d->m_cleanSession == cleanSession)
         return;
 
@@ -682,6 +719,12 @@ void QMqttClient::setCleanSession(bool cleanSession)
 void QMqttClient::setWillTopic(const QString &willTopic)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing will topic while connected is not possible.";
+        return;
+    }
+
     if (d->m_willTopic == willTopic)
         return;
 
@@ -692,6 +735,12 @@ void QMqttClient::setWillTopic(const QString &willTopic)
 void QMqttClient::setWillQoS(quint8 willQoS)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing will qos while connected is not possible.";
+        return;
+    }
+
     if (d->m_willQoS == willQoS)
         return;
 
@@ -702,6 +751,12 @@ void QMqttClient::setWillQoS(quint8 willQoS)
 void QMqttClient::setWillMessage(const QByteArray &willMessage)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing will message while connected is not possible.";
+        return;
+    }
+
     if (d->m_willMessage == willMessage)
         return;
 
@@ -712,6 +767,12 @@ void QMqttClient::setWillMessage(const QByteArray &willMessage)
 void QMqttClient::setWillRetain(bool willRetain)
 {
     Q_D(QMqttClient);
+
+    if (state() != QMqttClient::Disconnected) {
+        qCDebug(lcMqttClient) << "Changing will retain while connected is not possible.";
+        return;
+    }
+
     if (d->m_willRetain == willRetain)
         return;
 
@@ -763,4 +824,15 @@ void QMqttClientPrivate::setStateAndError(QMqttClient::ClientState s, QMqttClien
         q->setError(e);
 }
 
+void QMqttClientPrivate::setClientId(const QString &id)
+{
+    Q_Q(QMqttClient);
+
+    if (m_clientId == id)
+        return;
+
+    m_clientId = id;
+    emit q->clientIdChanged(id);
+}
+
 QT_END_NAMESPACE

src/mqtt/qmqttclient_p.h

@@ -57,6 +57,7 @@ public:
     QMqttClientPrivate(QMqttClient *c);
     ~QMqttClientPrivate() override;
     void setStateAndError(QMqttClient::ClientState s, QMqttClient::ClientError e = QMqttClient::NoError);
+    void setClientId(const QString &id);
     QMqttClient *m_client{nullptr};
     QString m_hostname;
     quint16 m_port{0};

src/mqtt/qmqttconnection.cpp

@@ -691,7 +691,7 @@ void QMqttConnection::readConnackProperties()
         case 0x12: { // 3.2.2.3.7 Assigned clientId
             const QString assignedClientId = readBufferTyped<QString>(&propertyLength);
             serverProperties.serverData->details |= QMqttServerConnectionProperties::AssignedClientId;
-            m_clientPrivate->m_client->setClientId(assignedClientId);
+            m_clientPrivate->setClientId(assignedClientId);
             break;
         }
         case 0x22: { // 3.2.2.3.8 Topic Alias Maximum

tests/auto/qmqttclient/tst_qmqttclient.cpp

@@ -66,6 +66,8 @@ private Q_SLOTS:
     void reconnect_QTBUG65726();
     void openIODevice_QTBUG66955_data();
     void openIODevice_QTBUG66955();
+    void staticProperties_QTBUG_67176_data();
+    void staticProperties_QTBUG_67176();
 private:
     QProcess m_brokerProcess;
     QString m_testBroker;
@@ -551,6 +553,48 @@ void Tst_QMqttClient::openIODevice_QTBUG66955()
     QTRY_COMPARE(trans.written, 1);
 }
 
+DefaultVersionTestData(Tst_QMqttClient::staticProperties_QTBUG_67176_data)
+
+void Tst_QMqttClient::staticProperties_QTBUG_67176()
+{
+    QFETCH(QMqttClient::ProtocolVersion, mqttVersion);
+
+    VersionClient(mqttVersion, client);
+    client.setHostname(m_testBroker);
+    client.setPort(m_port);
+
+    const QString clientId = client.clientId();
+    const quint16 keepAlive = client.keepAlive();
+    const bool clean = client.cleanSession();
+
+    client.connectToHost();
+    QTRY_VERIFY2(client.state() == QMqttClient::Connected, "Could not connect to broker.");
+
+    client.setClientId(QLatin1String("someclient"));
+    QCOMPARE(client.clientId(), clientId);
+
+    client.setHostname(QLatin1String("some.domain.foo"));
+    QCOMPARE(client.hostname(), m_testBroker);
+
+    client.setPort(1234);
+    QCOMPARE(client.port(), m_port);
+
+    client.setKeepAlive(keepAlive + 10);
+    QCOMPARE(client.keepAlive(), keepAlive);
+
+    client.setProtocolVersion(QMqttClient::MQTT_3_1);
+    QCOMPARE(client.protocolVersion(), mqttVersion);
+
+    client.setUsername(QLatin1String("someUser"));
+    QCOMPARE(client.username(), QLatin1String());
+
+    client.setPassword(QLatin1String("somePassword"));
+    QCOMPARE(client.password(), QLatin1String());
+
+    client.setCleanSession(!clean);
+    QCOMPARE(client.cleanSession(), clean);
+}
+
 QTEST_MAIN(Tst_QMqttClient)
 
 #include "tst_qmqttclient.moc"