20 files changed, 139 insertions, 137 deletions
diff --git a/src/dbus/Qt5DBusMacros.cmake b/src/dbus/Qt5DBusMacros.cmake
index b381ab0934..9b69e77dc7 100644
--- a/src/dbus/Qt5DBusMacros.cmake
+++ b/src/dbus/Qt5DBusMacros.cmake
@@ -34,7 +34,7 @@ include(MacroAddFileDependencies)
 
 include(CMakeParseArguments)
 
-function(QT5_ADD_DBUS_INTERFACE _sources _interface _basename)
+function(qt5_add_dbus_interface _sources _interface _basename)
     get_filename_component(_infile ${_interface} ABSOLUTE)
     set(_header "${CMAKE_CURRENT_BINARY_DIR}/${_basename}.h")
     set(_impl   "${CMAKE_CURRENT_BINARY_DIR}/${_basename}.cpp")
@@ -71,7 +71,7 @@ function(QT5_ADD_DBUS_INTERFACE _sources _interface _basename)
 endfunction()
 
 
-function(QT5_ADD_DBUS_INTERFACES _sources)
+function(qt5_add_dbus_interfaces _sources)
     foreach(_current_FILE ${ARGN})
         get_filename_component(_infile ${_current_FILE} ABSOLUTE)
         get_filename_component(_basename ${_current_FILE} NAME)
@@ -84,7 +84,7 @@ function(QT5_ADD_DBUS_INTERFACES _sources)
 endfunction()
 
 
-function(QT5_GENERATE_DBUS_INTERFACE _header) # _customName OPTIONS -some -options )
+function(qt5_generate_dbus_interface _header) # _customName OPTIONS -some -options )
     set(options)
     set(oneValueArgs)
     set(multiValueArgs OPTIONS)
@@ -117,7 +117,7 @@ function(QT5_GENERATE_DBUS_INTERFACE _header) # _customName OPTIONS -some -optio
 endfunction()
 
 
-function(QT5_ADD_DBUS_ADAPTOR _sources _xml_file _include _parentClass) # _optionalBasename _optionalClassName)
+function(qt5_add_dbus_adaptor _sources _xml_file _include _parentClass) # _optionalBasename _optionalClassName)
     get_filename_component(_infile ${_xml_file} ABSOLUTE)
 
     set(_optionalBasename "${ARGV4}")
diff --git a/src/dbus/qdbusabstractadaptor.cpp b/src/dbus/qdbusabstractadaptor.cpp
index 993607a643..bf0e33e26e 100644
--- a/src/dbus/qdbusabstractadaptor.cpp
+++ b/src/dbus/qdbusabstractadaptor.cpp
@@ -72,7 +72,7 @@ int QDBusAdaptorConnector::relaySlotMethodIndex()
 QDBusAdaptorConnector *qDBusFindAdaptorConnector(QObject *obj)
 {
     if (!obj)
-        return 0;
+        return nullptr;
     const QObjectList &children = obj->children();
     QObjectList::ConstIterator it = children.constBegin();
     QObjectList::ConstIterator end = children.constEnd();
@@ -83,7 +83,7 @@ QDBusAdaptorConnector *qDBusFindAdaptorConnector(QObject *obj)
             return connector;
         }
     }
-    return 0;
+    return nullptr;
 }
 
 QDBusAdaptorConnector *qDBusFindAdaptorConnector(QDBusAbstractAdaptor *adaptor)
@@ -411,7 +411,7 @@ void QDBusAdaptorConnector::qt_static_metacall(QObject *_o, QMetaObject::Call _c
 
 const QMetaObject QDBusAdaptorConnector::staticMetaObject = {
     { &QObject::staticMetaObject, qt_meta_stringdata_QDBusAdaptorConnector.data,
-      qt_meta_data_QDBusAdaptorConnector, qt_static_metacall, 0, 0 }
+      qt_meta_data_QDBusAdaptorConnector, qt_static_metacall, nullptr, nullptr }
 };
 
 const QMetaObject *QDBusAdaptorConnector::metaObject() const
@@ -421,7 +421,7 @@ const QMetaObject *QDBusAdaptorConnector::metaObject() const
 
 void *QDBusAdaptorConnector::qt_metacast(const char *_clname)
 {
-    if (!_clname) return 0;
+    if (!_clname) return nullptr;
     if (!strcmp(_clname, qt_meta_stringdata_QDBusAdaptorConnector.stringdata))
         return static_cast<void*>(const_cast< QDBusAdaptorConnector*>(this));
     return QObject::qt_metacast(_clname);
@@ -443,7 +443,7 @@ int QDBusAdaptorConnector::qt_metacall(QMetaObject::Call _c, int _id, void **_a)
 // SIGNAL 0
 void QDBusAdaptorConnector::relaySignal(QObject * _t1, const QMetaObject * _t2, int _t3, const QVariantList & _t4)
 {
-    void *_a[] = { 0, const_cast<void*>(reinterpret_cast<const void*>(&_t1)), const_cast<void*>(reinterpret_cast<const void*>(&_t2)), const_cast<void*>(reinterpret_cast<const void*>(&_t3)), const_cast<void*>(reinterpret_cast<const void*>(&_t4)) };
+    void *_a[] = { nullptr, const_cast<void*>(reinterpret_cast<const void*>(&_t1)), const_cast<void*>(reinterpret_cast<const void*>(&_t2)), const_cast<void*>(reinterpret_cast<const void*>(&_t3)), const_cast<void*>(reinterpret_cast<const void*>(&_t4)) };
     QMetaObject::activate(this, &staticMetaObject, 0, _a);
 }
 
diff --git a/src/dbus/qdbusabstractinterface.cpp b/src/dbus/qdbusabstractinterface.cpp
index 87de784fc0..b628c2b560 100644
--- a/src/dbus/qdbusabstractinterface.cpp
+++ b/src/dbus/qdbusabstractinterface.cpp
@@ -159,7 +159,7 @@ bool QDBusAbstractInterfacePrivate::property(const QMetaProperty &mp, void *retu
     const char *expectedSignature = "";
     if (int(mp.type()) != QMetaType::QVariant) {
         expectedSignature = QDBusMetaType::typeToSignature(type);
-        if (expectedSignature == 0) {
+        if (expectedSignature == nullptr) {
             qWarning("QDBusAbstractInterface: type %s must be registered with Qt D-Bus before it can be "
                      "used to read property %s.%s",
                      mp.typeName(), qPrintable(interface), mp.name());
@@ -190,7 +190,7 @@ bool QDBusAbstractInterfacePrivate::property(const QMetaProperty &mp, void *retu
     }
 
     QByteArray foundSignature;
-    const char *foundType = 0;
+    const char *foundType = nullptr;
     QVariant value = qvariant_cast<QDBusVariant>(reply.arguments().at(0)).variant();
 
     if (value.userType() == type || type == QMetaType::QVariant
@@ -597,7 +597,7 @@ bool QDBusAbstractInterface::callWithCallback(const QString &method,
                                               QObject *receiver,
                                               const char *slot)
 {
-    return callWithCallback(method, args, receiver, slot, 0);
+    return callWithCallback(method, args, receiver, slot, nullptr);
 }
 
 /*!
diff --git a/src/dbus/qdbusargument.cpp b/src/dbus/qdbusargument.cpp
index 764bc24165..5a0f0f013b 100644
--- a/src/dbus/qdbusargument.cpp
+++ b/src/dbus/qdbusargument.cpp
@@ -74,11 +74,11 @@ QByteArray QDBusArgumentPrivate::createSignature(int id)
     marshaller->ba = &signature;
 
     // run it
-    void *null = 0;
+    void *null = nullptr;
     QVariant v(id, null);
     QDBusArgument arg(marshaller);
     QDBusMetaType::marshall(arg, v.userType(), v.constData());
-    arg.d = 0;
+    arg.d = nullptr;
 
     // delete it
     bool ok = marshaller->ok;
@@ -290,7 +290,7 @@ bool QDBusArgumentPrivate::checkReadAndDetach(QDBusArgumentPrivate *&d)
 QDBusArgument::QDBusArgument()
 {
     if (!qdbus_loadLibDBus()) {
-        d = 0;
+        d = nullptr;
         return;
     }
 
diff --git a/src/dbus/qdbusconnection.cpp b/src/dbus/qdbusconnection.cpp
index d6f3230fd2..412b428bdc 100644
--- a/src/dbus/qdbusconnection.cpp
+++ b/src/dbus/qdbusconnection.cpp
@@ -101,7 +101,7 @@ QDBusConnectionPrivate *QDBusConnectionManager::busConnection(QDBusConnection::B
     Q_ASSERT(type == QDBusConnection::SessionBus || type == QDBusConnection::SystemBus);
 
     if (!qdbus_loadLibDBus())
-        return 0;
+        return nullptr;
 
     // we'll start in suspended delivery mode if we're in the main thread
     // (the event loop will resume delivery)
@@ -124,7 +124,7 @@ QDBusConnectionPrivate *QDBusConnectionManager::connection(const QString &name)
 
 void QDBusConnectionManager::removeConnection(const QString &name)
 {
-    QDBusConnectionPrivate *d = 0;
+    QDBusConnectionPrivate *d = nullptr;
     d = connectionHash.take(name);
     if (d && !d->ref.deref())
         d->deleteLater();
@@ -251,7 +251,7 @@ void QDBusConnectionManager::executeConnectionRequest(QDBusConnectionManager::Co
         return;
 
     d = new QDBusConnectionPrivate;
-    DBusConnection *c = 0;
+    DBusConnection *c = nullptr;
     QDBusErrorInternal error;
     switch (data->type) {
     case ConnectionRequestData::ConnectToStandardBus:
@@ -275,7 +275,7 @@ void QDBusConnectionManager::executeConnectionRequest(QDBusConnectionManager::Co
             // register on the bus
             if (!q_dbus_bus_register(c, error)) {
                 q_dbus_connection_unref(c);
-                c = 0;
+                c = nullptr;
             }
         }
         break;
@@ -427,7 +427,7 @@ void QDBusConnectionManager::createServer(const QString &address, void *server)
 QDBusConnection::QDBusConnection(const QString &name)
 {
     if (name.isEmpty() || _q_manager.isDestroyed()) {
-        d = 0;
+        d = nullptr;
     } else {
         const auto locker = qt_scoped_lock(_q_manager()->mutex);
         d = _q_manager()->connection(name);
@@ -492,7 +492,7 @@ QDBusConnection &QDBusConnection::operator=(const QDBusConnection &other)
 QDBusConnection QDBusConnection::connectToBus(BusType type, const QString &name)
 {
     if (_q_manager.isDestroyed() || !qdbus_loadLibDBus()) {
-        QDBusConnectionPrivate *d = 0;
+        QDBusConnectionPrivate *d = nullptr;
         return QDBusConnection(d);
     }
     return QDBusConnection(_q_manager()->connectToBus(type, name, false));
@@ -506,7 +506,7 @@ QDBusConnection QDBusConnection::connectToBus(const QString &address,
                                               const QString &name)
 {
     if (_q_manager.isDestroyed() || !qdbus_loadLibDBus()) {
-        QDBusConnectionPrivate *d = 0;
+        QDBusConnectionPrivate *d = nullptr;
         return QDBusConnection(d);
     }
     return QDBusConnection(_q_manager()->connectToBus(address, name));
@@ -521,7 +521,7 @@ QDBusConnection QDBusConnection::connectToPeer(const QString &address,
                                                const QString &name)
 {
     if (_q_manager.isDestroyed() || !qdbus_loadLibDBus()) {
-        QDBusConnectionPrivate *d = 0;
+        QDBusConnectionPrivate *d = nullptr;
         return QDBusConnection(d);
     }
     return QDBusConnection(_q_manager()->connectToPeer(address, name));
@@ -616,7 +616,7 @@ bool QDBusConnection::callWithCallback(const QDBusMessage &message, QObject *rec
             d->lastError = err;
         return false;
     }
-    return d->sendWithReplyAsync(message, receiver, returnMethod, errorMethod, timeout) != 0;
+    return d->sendWithReplyAsync(message, receiver, returnMethod, errorMethod, timeout) != nullptr;
 }
 
 /*!
@@ -639,7 +639,7 @@ bool QDBusConnection::callWithCallback(const QDBusMessage &message, QObject *rec
 bool QDBusConnection::callWithCallback(const QDBusMessage &message, QObject *receiver,
                                        const char *returnMethod, int timeout) const
 {
-    return callWithCallback(message, receiver, returnMethod, 0, timeout);
+    return callWithCallback(message, receiver, returnMethod, nullptr, timeout);
 }
 
 /*!
@@ -705,10 +705,10 @@ QDBusMessage QDBusConnection::call(const QDBusMessage &message, QDBus::CallMode
 QDBusPendingCall QDBusConnection::asyncCall(const QDBusMessage &message, int timeout) const
 {
     if (!d || !d->connection) {
-        return QDBusPendingCall(0); // null pointer -> disconnected
+        return QDBusPendingCall(nullptr); // null pointer -> disconnected
     }
 
-    QDBusPendingCallPrivate *priv = d->sendWithReplyAsync(message, 0, 0, 0, timeout);
+    QDBusPendingCallPrivate *priv = d->sendWithReplyAsync(message, nullptr, nullptr, nullptr, timeout);
     return QDBusPendingCall(priv);
 }
 
@@ -1015,7 +1015,7 @@ QObject *QDBusConnection::objectRegisteredAt(const QString &path) const
     Q_ASSERT_X(QDBusUtil::isValidObjectPath(path), "QDBusConnection::registeredObject",
                "Invalid object path given");
     if (!d || !d->connection || !QDBusUtil::isValidObjectPath(path))
-        return 0;
+        return nullptr;
 
     auto pathComponents = path.splitRef(QLatin1Char('/'));
     if (pathComponents.constLast().isEmpty())
@@ -1040,7 +1040,7 @@ QObject *QDBusConnection::objectRegisteredAt(const QString &path) const
         node = it;
         ++i;
     }
-    return 0;
+    return nullptr;
 }
 
 
@@ -1052,7 +1052,7 @@ QObject *QDBusConnection::objectRegisteredAt(const QString &path) const
 QDBusConnectionInterface *QDBusConnection::interface() const
 {
     if (!d || d->mode != QDBusConnectionPrivate::ClientMode)
-        return 0;
+        return nullptr;
     return d->busService;
 }
 
@@ -1068,7 +1068,7 @@ QDBusConnectionInterface *QDBusConnection::interface() const
 */
 void *QDBusConnection::internalPointer() const
 {
-    return d ? d->connection : 0;
+    return d ? d->connection : nullptr;
 }
 
 /*!
@@ -1139,7 +1139,7 @@ QString QDBusConnection::name() const
 */
 QDBusConnection::ConnectionCapabilities QDBusConnection::connectionCapabilities() const
 {
-    return d ? d->capabilities : ConnectionCapabilities(0);
+    return d ? d->capabilities : ConnectionCapabilities();
 }
 
 /*!
diff --git a/src/dbus/qdbuscontext.cpp b/src/dbus/qdbuscontext.cpp
index 5b21c4fa74..de0482be70 100644
--- a/src/dbus/qdbuscontext.cpp
+++ b/src/dbus/qdbuscontext.cpp
@@ -64,7 +64,7 @@ QDBusContextPrivate *QDBusContextPrivate::set(QObject *obj, QDBusContextPrivate
         return old;
     }
 
-    return 0;
+    return nullptr;
 }
 
 /*!
@@ -104,7 +104,7 @@ QDBusContextPrivate *QDBusContextPrivate::set(QObject *obj, QDBusContextPrivate
   Constructs an empty QDBusContext.
  */
 QDBusContext::QDBusContext()
-    : d_ptr(0)
+    : d_ptr(nullptr)
 {
 }
 
diff --git a/src/dbus/qdbusdemarshaller.cpp b/src/dbus/qdbusdemarshaller.cpp
index 6befb33d61..c9da593ad2 100644
--- a/src/dbus/qdbusdemarshaller.cpp
+++ b/src/dbus/qdbusdemarshaller.cpp
@@ -295,7 +295,7 @@ QVariant QDBusDemarshaller::toVariantInternal()
 //        qWarning("QDBusDemarshaller: Found unknown D-Bus type %d '%c'",
 //                 q_dbus_message_iter_get_arg_type(&iterator),
 //                 q_dbus_message_iter_get_arg_type(&iterator));
-        char *ptr = 0;
+        char *ptr = nullptr;
         ptr += q_dbus_message_iter_get_arg_type(&iterator);
         q_dbus_message_iter_next(&iterator);
 
diff --git a/src/dbus/qdbusintegrator.cpp b/src/dbus/qdbusintegrator.cpp
index 4c27a93382..bca02be59e 100644
--- a/src/dbus/qdbusintegrator.cpp
+++ b/src/dbus/qdbusintegrator.cpp
@@ -127,7 +127,7 @@ void qdbusDefaultThreadDebug(int action, int condition, QDBusConnectionPrivate *
                      "condition unknown")
                  << "in connection" << conn;
 }
-qdbusThreadDebugFunc qdbusThreadDebug = 0;
+qdbusThreadDebugFunc qdbusThreadDebug = nullptr;
 #endif
 
 typedef QVarLengthArray<QDBusSpyCallEvent::Hook, 4> QDBusSpyHookList;
@@ -222,7 +222,7 @@ static dbus_bool_t qDBusAddWatch(DBusWatch *watch, void *data)
         watcher.write->setEnabled(q_dbus_watch_get_enabled(watch));
         d->connect(watcher.write, &QSocketNotifier::activated, d, &QDBusConnectionPrivate::socketWrite);
     }
-    d->watchers.insertMulti(fd, watcher);
+    d->watchers.insert(fd, watcher);
 
     return true;
 }
@@ -400,7 +400,7 @@ static bool findObject(const QDBusConnectionPrivate::ObjectTreeNode *root,
             // match
             node = it;
         else
-            node = 0;
+            node = nullptr;
 
         start = end + 1;
     }
@@ -413,7 +413,7 @@ static bool findObject(const QDBusConnectionPrivate::ObjectTreeNode *root,
         else
             // there really is no object here
             // we're just looking at an unused space in the QVector
-            node = 0;
+            node = nullptr;
     }
     return node;
 }
@@ -440,7 +440,7 @@ static QObject *findChildObject(const QDBusConnectionPrivate::ObjectTreeNode *ro
             const QObjectList children = obj->children();
 
             // find a child with the proper name
-            QObject *next = 0;
+            QObject *next = nullptr;
             QObjectList::ConstIterator it = children.constBegin();
             QObjectList::ConstIterator end = children.constEnd();
             for ( ; it != end; ++it)
@@ -458,7 +458,7 @@ static QObject *findChildObject(const QDBusConnectionPrivate::ObjectTreeNode *ro
     }
 
     // object not found
-    return 0;
+    return nullptr;
 }
 
 static QDBusConnectionPrivate::ArgMatchRules matchArgsForService(const QString &service, QDBusServiceWatcher::WatchMode mode)
@@ -599,7 +599,7 @@ static void huntAndDestroy(QObject *needle, QDBusConnectionPrivate::ObjectTreeNo
                             haystack.children.end());
 
     if (needle == haystack.obj) {
-        haystack.obj = 0;
+        haystack.obj = nullptr;
         haystack.flags = 0;
     }
 }
@@ -609,7 +609,7 @@ static void huntAndUnregister(const QVector<QStringRef> &pathComponents, int i,
 {
     if (pathComponents.count() == i) {
         // found it
-        node->obj = 0;
+        node->obj = nullptr;
         node->flags = 0;
 
         if (mode == QDBusConnection::UnregisterTree) {
@@ -660,7 +660,7 @@ static void huntAndEmit(DBusConnection *connection, DBusMessage *msg,
         qDBusDebug() << QThread::currentThread() << "emitting signal at" << p;
         DBusMessage *msg2 = q_dbus_message_copy(msg);
         q_dbus_message_set_path(msg2, p);
-        q_dbus_connection_send(connection, msg2, 0);
+        q_dbus_connection_send(connection, msg2, nullptr);
         q_dbus_message_unref(msg2);
     }
 }
@@ -727,12 +727,12 @@ static int findSlot(const QMetaObject *mo, const QByteArray &name, int flags,
             ++i;
 
         // make sure that the output parameters have signatures too
-        if (returnType != QMetaType::UnknownType && returnType != QMetaType::Void && QDBusMetaType::typeToSignature(returnType) == 0)
+        if (returnType != QMetaType::UnknownType && returnType != QMetaType::Void && QDBusMetaType::typeToSignature(returnType) == nullptr)
             continue;
 
         bool ok = true;
         for (int j = i; ok && j < metaTypes.count(); ++j)
-            if (QDBusMetaType::typeToSignature(metaTypes.at(i)) == 0)
+            if (QDBusMetaType::typeToSignature(metaTypes.at(i)) == nullptr)
                 ok = false;
         if (!ok)
             continue;
@@ -790,13 +790,13 @@ QDBusCallDeliveryEvent* QDBusConnectionPrivate::prepareReply(QDBusConnectionPriv
         --n;
 
     if (msg.arguments().count() < n)
-        return 0;               // too few arguments
+        return nullptr;               // too few arguments
 
     // check that types match
     for (int i = 0; i < n; ++i)
         if (metaTypes.at(i + 1) != msg.arguments().at(i).userType() &&
             msg.arguments().at(i).userType() != qMetaTypeId<QDBusArgument>())
-            return 0;           // no match
+            return nullptr;           // no match
 
     // we can deliver
     // prepare for the call
@@ -944,7 +944,7 @@ void QDBusConnectionPrivate::deliverCall(QObject *object, int /*flags*/, const Q
             params.append(const_cast<void *>(arg.constData()));
         else if (arg.userType() == qMetaTypeId<QDBusArgument>()) {
             // convert to what the function expects
-            void *null = 0;
+            void *null = nullptr;
             auxParameters.append(QVariant(id, null));
 
             const QDBusArgument &in =
@@ -972,7 +972,7 @@ void QDBusConnectionPrivate::deliverCall(QObject *object, int /*flags*/, const Q
     // output arguments
     const int numMetaTypes = metaTypes.count();
     QVariantList outputArgs;
-    void *null = 0;
+    void *null = nullptr;
     if (metaTypes[0] != QMetaType::Void && metaTypes[0] != QMetaType::UnknownType) {
         outputArgs.reserve(numMetaTypes - i + 1);
         QVariant arg(metaTypes[0], null);
@@ -1026,8 +1026,8 @@ void QDBusConnectionPrivate::deliverCall(QObject *object, int /*flags*/, const Q
 extern bool qDBusInitThreads();
 
 QDBusConnectionPrivate::QDBusConnectionPrivate(QObject *p)
-    : QObject(p), ref(1), capabilities(0), mode(InvalidMode), busService(0),
-      connection(0),
+    : QObject(p), ref(1), mode(InvalidMode), busService(nullptr),
+      connection(nullptr),
       rootNode(QString(QLatin1Char('/'))),
       anonymousAuthenticationAllowed(false),
       dispatchEnabled(true)
@@ -1087,11 +1087,11 @@ QDBusConnectionPrivate::~QDBusConnectionPrivate()
         }
         if (connection)
             q_dbus_connection_unref(connection);
-        connection = 0;
+        connection = nullptr;
     } else if (lastMode == ServerMode) {
         if (server)
             q_dbus_server_unref(server);
-        server = 0;
+        server = nullptr;
     }
 }
 
@@ -1531,7 +1531,7 @@ void QDBusConnectionPrivate::handleObjectCall(const QDBusMessage &msg)
     // user code, if necessary.
     ObjectTreeNode result;
     int usedLength;
-    QThread *objThread = 0;
+    QThread *objThread = nullptr;
     QSemaphore sem;
     bool semWait;
 
@@ -1718,7 +1718,7 @@ void QDBusConnectionPrivate::setServer(QDBusServer *object, DBusServer *s, const
                                                                       qDBusAddWatch,
                                                                       qDBusRemoveWatch,
                                                                       qDBusToggleWatch,
-                                                                      this, 0);
+                                                                      this, nullptr);
     //qDebug() << "watch_functions_set" << watch_functions_set;
     Q_UNUSED(watch_functions_set);
 
@@ -1726,13 +1726,13 @@ void QDBusConnectionPrivate::setServer(QDBusServer *object, DBusServer *s, const
                                                                        qDBusAddTimeout,
                                                                        qDBusRemoveTimeout,
                                                                        qDBusToggleTimeout,
-                                                                       this, 0);
+                                                                       this, nullptr);
     //qDebug() << "time_functions_set" << time_functions_set;
     Q_UNUSED(time_functions_set);
 
-    q_dbus_server_set_new_connection_function(server, qDBusNewConnection, this, 0);
+    q_dbus_server_set_new_connection_function(server, qDBusNewConnection, this, nullptr);
 
-    dbus_bool_t data_set = q_dbus_server_set_data(server, server_slot, this, 0);
+    dbus_bool_t data_set = q_dbus_server_set_data(server, server_slot, this, nullptr);
     //qDebug() << "data_set" << data_set;
     Q_UNUSED(data_set);
 }
@@ -1752,16 +1752,16 @@ void QDBusConnectionPrivate::setPeer(DBusConnection *c, const QDBusErrorInternal
                                         qDBusAddWatch,
                                         qDBusRemoveWatch,
                                         qDBusToggleWatch,
-                                        this, 0);
+                                        this, nullptr);
     q_dbus_connection_set_timeout_functions(connection,
                                           qDBusAddTimeout,
                                           qDBusRemoveTimeout,
                                           qDBusToggleTimeout,
-                                          this, 0);
-    q_dbus_connection_set_dispatch_status_function(connection, qDBusUpdateDispatchStatus, this, 0);
+                                          this, nullptr);
+    q_dbus_connection_set_dispatch_status_function(connection, qDBusUpdateDispatchStatus, this, nullptr);
     q_dbus_connection_add_filter(connection,
                                qDBusSignalFilter,
-                               this, 0);
+                               this, nullptr);
 
     watchForDBusDisconnection();
 
@@ -1770,9 +1770,9 @@ void QDBusConnectionPrivate::setPeer(DBusConnection *c, const QDBusErrorInternal
 
 static QDBusConnection::ConnectionCapabilities connectionCapabilies(DBusConnection *connection)
 {
-    QDBusConnection::ConnectionCapabilities result = 0;
+    QDBusConnection::ConnectionCapabilities result;
     typedef dbus_bool_t (*can_send_type_t)(DBusConnection *, int);
-    static can_send_type_t can_send_type = 0;
+    static can_send_type_t can_send_type = nullptr;
 
 #if defined(QT_LINKED_LIBDBUS)
 # if DBUS_VERSION-0 >= 0x010400
@@ -1809,11 +1809,11 @@ void QDBusConnectionPrivate::setConnection(DBusConnection *dbc, const QDBusError
 
     q_dbus_connection_set_exit_on_disconnect(connection, false);
     q_dbus_connection_set_watch_functions(connection, qDBusAddWatch, qDBusRemoveWatch,
-                                          qDBusToggleWatch, this, 0);
+                                          qDBusToggleWatch, this, nullptr);
     q_dbus_connection_set_timeout_functions(connection, qDBusAddTimeout, qDBusRemoveTimeout,
-                                            qDBusToggleTimeout, this, 0);
-    q_dbus_connection_set_dispatch_status_function(connection, qDBusUpdateDispatchStatus, this, 0);
-    q_dbus_connection_add_filter(connection, qDBusSignalFilter, this, 0);
+                                            qDBusToggleTimeout, this, nullptr);
+    q_dbus_connection_set_dispatch_status_function(connection, qDBusUpdateDispatchStatus, this, nullptr);
+    q_dbus_connection_add_filter(connection, qDBusSignalFilter, this, nullptr);
 
     // Initialize the hooks for the NameAcquired and NameLost signals
     // we don't use connectSignal here because we don't need the rules to be sent to the bus
@@ -1904,7 +1904,7 @@ void QDBusConnectionPrivate::processFinishedCall(QDBusPendingCallPrivate *call)
 
     if (call->pending) {
         q_dbus_pending_call_unref(call->pending);
-        call->pending = 0;
+        call->pending = nullptr;
     }
 
     // Are there any watchers?
@@ -2046,7 +2046,7 @@ QDBusMessage QDBusConnectionPrivate::sendWithReply(const QDBusMessage &message,
 {
     QDBusBlockingCallWatcher watcher(message);
 
-    QDBusPendingCallPrivate *pcall = sendWithReplyAsync(message, 0, 0, 0, timeout);
+    QDBusPendingCallPrivate *pcall = sendWithReplyAsync(message, nullptr, nullptr, nullptr, timeout);
     Q_ASSERT(pcall);
 
     if (pcall->replyMessage.type() == QDBusMessage::InvalidMessage) {
@@ -2161,7 +2161,7 @@ QDBusPendingCallPrivate *QDBusConnectionPrivate::sendWithReplyAsync(const QDBusM
 void QDBusConnectionPrivate::sendInternal(QDBusPendingCallPrivate *pcall, void *message, int timeout)
 {
     QDBusError error;
-    DBusPendingCall *pending = 0;
+    DBusPendingCall *pending = nullptr;
     DBusMessage *msg = static_cast<DBusMessage *>(message);
     bool isNoReply = !pcall;
     Q_ASSERT(isNoReply == !!q_dbus_message_get_no_reply(msg));
@@ -2175,7 +2175,7 @@ void QDBusConnectionPrivate::sendInternal(QDBusPendingCallPrivate *pcall, void *
             q_dbus_message_unref(msg);
 
             pcall->pending = pending;
-            q_dbus_pending_call_set_notify(pending, qDBusResultReceived, pcall, 0);
+            q_dbus_pending_call_set_notify(pending, qDBusResultReceived, pcall, nullptr);
 
             // DBus won't notify us when a peer disconnects or server terminates so we need to track these ourselves
             if (mode == QDBusConnectionPrivate::PeerMode || mode == QDBusConnectionPrivate::ClientMode)
@@ -2245,7 +2245,7 @@ bool QDBusConnectionPrivate::addSignalHook(const QString &key, const SignalHook
         }
     }
 
-    signalHooks.insertMulti(key, hook);
+    signalHooks.insert(key, hook);
     connect(hook.obj, &QObject::destroyed, this, &QDBusConnectionPrivate::objectDestroyed,
             Qt::ConnectionType(Qt::BlockingQueuedConnection | Qt::UniqueConnection));
 
@@ -2261,7 +2261,7 @@ bool QDBusConnectionPrivate::addSignalHook(const QString &key, const SignalHook
     if (connection) {
         if (mode != QDBusConnectionPrivate::PeerMode) {
             qDBusDebug() << this << "Adding rule:" << hook.matchRule;
-            q_dbus_bus_add_match(connection, hook.matchRule, NULL);
+            q_dbus_bus_add_match(connection, hook.matchRule, nullptr);
 
             // Successfully connected the signal
             // Do we need to watch for this name?
@@ -2274,7 +2274,7 @@ bool QDBusConnectionPrivate::addSignalHook(const QString &key, const SignalHook
                     q_dbus_bus_add_match(connection,
                                          buildMatchRule(QDBusUtil::dbusService(), QString(), QDBusUtil::dbusInterface(),
                                                         QDBusUtil::nameOwnerChanged(), rules, QString()),
-                                         NULL);
+                                         nullptr);
                     data.owner = getNameOwnerNoCache(hook.service);
                     qDBusDebug() << this << "Watching service" << hook.service << "for owner changes (current owner:"
                                  << data.owner << ")";
@@ -2362,7 +2362,7 @@ QDBusConnectionPrivate::removeSignalHookNoLock(SignalHookHash::Iterator it)
     if (connection && erase) {
         if (mode != QDBusConnectionPrivate::PeerMode) {
             qDBusDebug() << this << "Removing rule:" << hook.matchRule;
-            q_dbus_bus_remove_match(connection, hook.matchRule, NULL);
+            q_dbus_bus_remove_match(connection, hook.matchRule, nullptr);
 
             // Successfully disconnected the signal
             // Were we watching for this name?
@@ -2375,7 +2375,7 @@ QDBusConnectionPrivate::removeSignalHookNoLock(SignalHookHash::Iterator it)
                     q_dbus_bus_remove_match(connection,
                                             buildMatchRule(QDBusUtil::dbusService(), QString(), QDBusUtil::dbusInterface(),
                                                            QDBusUtil::nameOwnerChanged(), rules, QString()),
-                                            NULL);
+                                            nullptr);
                 }
             }
         }
@@ -2575,7 +2575,7 @@ QDBusConnectionPrivate::findMetaObject(const QString &service, const QString &pa
 
     // it doesn't exist yet, we have to create it
     QDBusWriteLocker locker(FindMetaObject2Action, this);
-    QDBusMetaObject *mo = 0;
+    QDBusMetaObject *mo = nullptr;
     if (!interface.isEmpty())
         mo = cachedMetaObjects.value(interface, 0);
     if (mo)
@@ -2591,7 +2591,7 @@ QDBusConnectionPrivate::findMetaObject(const QString &service, const QString &pa
         error = QDBusError(reply);
         lastError = error;
         if (reply.type() != QDBusMessage::ErrorMessage || error.type() != QDBusError::UnknownMethod)
-            return 0; // error
+            return nullptr; // error
     }
 
     // release the lock and return
diff --git a/src/dbus/qdbusinterface.cpp b/src/dbus/qdbusinterface.cpp
index 4dd02e8c76..72b9d42247 100644
--- a/src/dbus/qdbusinterface.cpp
+++ b/src/dbus/qdbusinterface.cpp
@@ -149,7 +149,7 @@ static void copyArgument(void *to, int id, const QVariant &arg)
 
 QDBusInterfacePrivate::QDBusInterfacePrivate(const QString &serv, const QString &p,
                                              const QString &iface, const QDBusConnection &con)
-    : QDBusAbstractInterfacePrivate(serv, p, iface, con, true), metaObject(0)
+    : QDBusAbstractInterfacePrivate(serv, p, iface, con, true), metaObject(nullptr)
 {
     // QDBusAbstractInterfacePrivate's constructor checked the parameters for us
     if (connection.isConnected()) {
@@ -204,7 +204,9 @@ QDBusInterfacePrivate::~QDBusInterfacePrivate()
     interface \a interface on object at path \a path on service \a
     service, using the given \a connection. If \a interface is an
     empty string, the object created will refer to the merging of all
-    interfaces found in that object.
+    interfaces found by introspecting that object. Otherwise if
+    \a interface is not empty, the  QDBusInterface object will be cached
+    to speedup further creations of the same interface.
 
     \a parent is passed to the base class constructor.
 
@@ -243,7 +245,7 @@ const QMetaObject *QDBusInterface::metaObject() const
 */
 void *QDBusInterface::qt_metacast(const char *_clname)
 {
-    if (!_clname) return 0;
+    if (!_clname) return nullptr;
     if (!strcmp(_clname, "QDBusInterface"))
         return static_cast<void*>(const_cast<QDBusInterface*>(this));
     if (d_func()->interface.toLatin1() == _clname)
diff --git a/src/dbus/qdbusinternalfilters.cpp b/src/dbus/qdbusinternalfilters.cpp
index edee4fc1e5..74cc470596 100644
--- a/src/dbus/qdbusinternalfilters.cpp
+++ b/src/dbus/qdbusinternalfilters.cpp
@@ -358,7 +358,7 @@ static int writeProperty(QObject *obj, const QByteArray &property_name, QVariant
 
     if (id != QMetaType::QVariant && value.userType() == QDBusMetaTypeId::argument()) {
         // we have to demarshall before writing
-        void *null = 0;
+        void *null = nullptr;
         QVariant other(id, null);
         if (!QDBusMetaType::demarshall(qvariant_cast<QDBusArgument>(value), id, other.data())) {
             qWarning("QDBusConnection: type `%s' (%d) is not registered with QtDBus. "
diff --git a/src/dbus/qdbusmarshaller.cpp b/src/dbus/qdbusmarshaller.cpp
index 8e0b3e4598..46b41d1c07 100644
--- a/src/dbus/qdbusmarshaller.cpp
+++ b/src/dbus/qdbusmarshaller.cpp
@@ -197,7 +197,7 @@ inline bool QDBusMarshaller::append(const QDBusVariant &arg)
     }
 
     QByteArray tmpSignature;
-    const char *signature = 0;
+    const char *signature = nullptr;
     if (id == QDBusMetaTypeId::argument()) {
         // take the signature from the QDBusArgument object we're marshalling
         tmpSignature =
@@ -243,7 +243,7 @@ inline void QDBusMarshaller::append(const QStringList &arg)
 
 inline QDBusMarshaller *QDBusMarshaller::beginStructure()
 {
-    return beginCommon(DBUS_TYPE_STRUCT, 0);
+    return beginCommon(DBUS_TYPE_STRUCT, nullptr);
 }
 
 inline QDBusMarshaller *QDBusMarshaller::beginArray(int id)
@@ -301,7 +301,7 @@ inline QDBusMarshaller *QDBusMarshaller::beginMap(int kid, int vid)
 
 inline QDBusMarshaller *QDBusMarshaller::beginMapEntry()
 {
-    return beginCommon(DBUS_TYPE_DICT_ENTRY, 0);
+    return beginCommon(DBUS_TYPE_DICT_ENTRY, nullptr);
 }
 
 void QDBusMarshaller::open(QDBusMarshaller &sub, int code, const char *signature)
@@ -572,7 +572,7 @@ bool QDBusMarshaller::appendCrossMarshalling(QDBusDemarshaller *demarshaller)
 
     QDBusMarshaller mrecursed(capabilities);  // create on the stack makes it autoclose
     QByteArray subSignature;
-    const char *sig = 0;
+    const char *sig = nullptr;
     if (code == DBUS_TYPE_VARIANT || code == DBUS_TYPE_ARRAY) {
         subSignature = drecursed->currentSignature().toLatin1();
         if (!subSignature.isEmpty())
diff --git a/src/dbus/qdbusmessage.cpp b/src/dbus/qdbusmessage.cpp
index 3e8f2eaf3f..71cdec93ca 100644
--- a/src/dbus/qdbusmessage.cpp
+++ b/src/dbus/qdbusmessage.cpp
@@ -64,11 +64,11 @@ Q_STATIC_ASSERT(QDBusMessage::SignalMessage == DBUS_MESSAGE_TYPE_SIGNAL);
 
 static inline const char *data(const QByteArray &arr)
 {
-    return arr.isEmpty() ? 0 : arr.constData();
+    return arr.isEmpty() ? nullptr : arr.constData();
 }
 
 QDBusMessagePrivate::QDBusMessagePrivate()
-    : msg(0), reply(0), localReply(0), ref(1), type(QDBusMessage::InvalidMessage),
+    : msg(nullptr), reply(nullptr), localReply(nullptr), ref(1), type(QDBusMessage::InvalidMessage),
       delayedReply(false), localMessage(false),
       parametersValidated(false), autoStartService(true),
       interactiveAuthorizationAllowed(false)
@@ -113,10 +113,10 @@ DBusMessage *QDBusMessagePrivate::toDBusMessage(const QDBusMessage &message, QDB
 {
     if (!qdbus_loadLibDBus()) {
         *error = QDBusError(QDBusError::Failed, QLatin1String("Could not open lidbus-1 library"));
-        return 0;
+        return nullptr;
     }
 
-    DBusMessage *msg = 0;
+    DBusMessage *msg = nullptr;
     const QDBusMessagePrivate *d_ptr = message.d_ptr;
 
     switch (d_ptr->type) {
@@ -127,13 +127,13 @@ DBusMessage *QDBusMessagePrivate::toDBusMessage(const QDBusMessage &message, QDB
         // only service and interface can be empty -> path and name must not be empty
         if (!d_ptr->parametersValidated) {
             if (!QDBusUtil::checkBusName(d_ptr->service, QDBusUtil::EmptyAllowed, error))
-                return 0;
+                return nullptr;
             if (!QDBusUtil::checkObjectPath(d_ptr->path, QDBusUtil::EmptyNotAllowed, error))
-                return 0;
+                return nullptr;
             if (!QDBusUtil::checkInterfaceName(d_ptr->interface, QDBusUtil::EmptyAllowed, error))
-                return 0;
+                return nullptr;
             if (!QDBusUtil::checkMemberName(d_ptr->name, QDBusUtil::EmptyNotAllowed, error, "method"))
-                return 0;
+                return nullptr;
         }
 
         msg = q_dbus_message_new_method_call(data(d_ptr->service.toUtf8()), d_ptr->path.toUtf8(),
@@ -153,7 +153,7 @@ DBusMessage *QDBusMessagePrivate::toDBusMessage(const QDBusMessage &message, QDB
         // error name can't be empty
         if (!d_ptr->parametersValidated
             && !QDBusUtil::checkErrorName(d_ptr->name, QDBusUtil::EmptyNotAllowed, error))
-            return 0;
+            return nullptr;
 
         msg = q_dbus_message_new(DBUS_MESSAGE_TYPE_ERROR);
         q_dbus_message_set_error_name(msg, d_ptr->name.toUtf8());
@@ -166,13 +166,13 @@ DBusMessage *QDBusMessagePrivate::toDBusMessage(const QDBusMessage &message, QDB
         // only the service name can be empty here
         if (!d_ptr->parametersValidated) {
             if (!QDBusUtil::checkBusName(d_ptr->service, QDBusUtil::EmptyAllowed, error))
-                return 0;
+                return nullptr;
             if (!QDBusUtil::checkObjectPath(d_ptr->path, QDBusUtil::EmptyNotAllowed, error))
-                return 0;
+                return nullptr;
             if (!QDBusUtil::checkInterfaceName(d_ptr->interface, QDBusUtil::EmptyAllowed, error))
-                return 0;
+                return nullptr;
             if (!QDBusUtil::checkMemberName(d_ptr->name, QDBusUtil::EmptyNotAllowed, error, "method"))
-                return 0;
+                return nullptr;
         }
 
         msg = q_dbus_message_new_signal(d_ptr->path.toUtf8(), d_ptr->interface.toUtf8(),
@@ -203,7 +203,7 @@ DBusMessage *QDBusMessagePrivate::toDBusMessage(const QDBusMessage &message, QDB
     // not ok;
     q_dbus_message_unref(msg);
     *error = QDBusError(QDBusError::Failed, QLatin1String("Marshalling failed: ") + marshaller.errorString);
-    return 0;
+    return nullptr;
 }
 
 /*
diff --git a/src/dbus/qdbusmetaobject.cpp b/src/dbus/qdbusmetaobject.cpp
index 806cf7b415..74e17ced77 100644
--- a/src/dbus/qdbusmetaobject.cpp
+++ b/src/dbus/qdbusmetaobject.cpp
@@ -138,7 +138,7 @@ static int registerComplexDBusType(const char *typeName)
         static void *construct(void *, const void *)
         {
             qFatal("Cannot construct placeholder type QDBusRawType");
-            return 0;
+            return nullptr;
         }
     };
 
@@ -147,7 +147,7 @@ static int registerComplexDBusType(const char *typeName)
                                              QDBusRawTypeHandler::construct,
                                              sizeof(void *),
                                              QMetaType::MovableType,
-                                             0);
+                                             nullptr);
 }
 
 Q_DBUS_EXPORT bool qt_dbus_metaobject_skip_annotations = false;
@@ -544,9 +544,9 @@ void QDBusMetaObjectGenerator::write(QDBusMetaObject *obj)
 
     // put the metaobject together
     obj->d.data = uint_data;
-    obj->d.relatedMetaObjects = 0;
-    obj->d.static_metacall = 0;
-    obj->d.extradata = 0;
+    obj->d.relatedMetaObjects = nullptr;
+    obj->d.static_metacall = nullptr;
+    obj->d.extradata = nullptr;
     obj->d.stringdata = reinterpret_cast<const QByteArrayData *>(string_data);
     obj->d.superdata = &QDBusAbstractInterface::staticMetaObject;
 }
@@ -587,7 +587,7 @@ QDBusMetaObject *QDBusMetaObject::createMetaObject(const QString &interface, con
     error = QDBusError();
     QDBusIntrospection::Interfaces parsed = QDBusIntrospection::parseInterfaces(xml);
 
-    QDBusMetaObject *we = 0;
+    QDBusMetaObject *we = nullptr;
     QDBusIntrospection::Interfaces::ConstIterator it = parsed.constBegin();
     QDBusIntrospection::Interfaces::ConstIterator end = parsed.constEnd();
     for ( ; it != end; ++it) {
@@ -621,7 +621,7 @@ QDBusMetaObject *QDBusMetaObject::createMetaObject(const QString &interface, con
     if (parsed.isEmpty()) {
         // object didn't return introspection
         we = new QDBusMetaObject;
-        QDBusMetaObjectGenerator generator(interface, 0);
+        QDBusMetaObjectGenerator generator(interface, nullptr);
         generator.write(we);
         we->cached = false;
         return we;
@@ -651,7 +651,7 @@ QDBusMetaObject *QDBusMetaObject::createMetaObject(const QString &interface, con
     error = QDBusError(QDBusError::UnknownInterface,
         QLatin1String("Interface '%1' was not found")
                        .arg(interface));
-    return 0;
+    return nullptr;
 }
 
 QDBusMetaObject::QDBusMetaObject()
@@ -670,7 +670,7 @@ const int *QDBusMetaObject::inputTypesForMethod(int id) const
         int handle = priv(d.data)->methodDBusData + id*intsPerMethod;
         return reinterpret_cast<const int*>(d.data + d.data[handle]);
     }
-    return 0;
+    return nullptr;
 }
 
 const int *QDBusMetaObject::outputTypesForMethod(int id) const
@@ -680,7 +680,7 @@ const int *QDBusMetaObject::outputTypesForMethod(int id) const
         int handle = priv(d.data)->methodDBusData + id*intsPerMethod;
         return reinterpret_cast<const int*>(d.data + d.data[handle + 1]);
     }
-    return 0;
+    return nullptr;
 }
 
 int QDBusMetaObject::propertyMetaType(int id) const
diff --git a/src/dbus/qdbusmetatype.cpp b/src/dbus/qdbusmetatype.cpp
index 58ce4f8930..e3804f74f8 100644
--- a/src/dbus/qdbusmetatype.cpp
+++ b/src/dbus/qdbusmetatype.cpp
@@ -67,7 +67,7 @@ QT_BEGIN_NAMESPACE
 class QDBusCustomTypeInfo
 {
 public:
-    QDBusCustomTypeInfo() : signature(), marshall(0), demarshall(0)
+    QDBusCustomTypeInfo() : signature(), marshall(nullptr), demarshall(nullptr)
     { }
 
     // Suggestion:
@@ -78,7 +78,7 @@ public:
 };
 
 template<typename T>
-inline static void registerHelper(T * = 0)
+inline static void registerHelper(T * = nullptr)
 {
     void (*mf)(QDBusArgument &, const T *) = qDBusMarshallHelper<T>;
     void (*df)(const QDBusArgument &, T *) = qDBusDemarshallHelper<T>;
@@ -259,7 +259,7 @@ bool QDBusMetaType::marshall(QDBusArgument &arg, int id, const void *data)
 
         const QDBusCustomTypeInfo &info = (*ct).at(id);
         if (!info.marshall) {
-            mf = 0;             // make gcc happy
+            mf = nullptr;       // make gcc happy
             return false;
         } else
             mf = info.marshall;
@@ -288,7 +288,7 @@ bool QDBusMetaType::demarshall(const QDBusArgument &arg, int id, void *data)
 
         const QDBusCustomTypeInfo &info = (*ct).at(id);
         if (!info.demarshall) {
-            df = 0;             // make gcc happy
+            df = nullptr;       // make gcc happy
             return false;
         } else
             df = info.demarshall;
@@ -460,7 +460,7 @@ const char *QDBusMetaType::typeToSignature(int type)
     {
         QReadLocker locker(customTypesLock());
         if (type >= ct->size())
-            return 0;           // type not registered with us
+            return nullptr;           // type not registered with us
 
         const QDBusCustomTypeInfo &info = (*ct).at(type);
 
@@ -468,7 +468,7 @@ const char *QDBusMetaType::typeToSignature(int type)
             return info.signature;
 
         if (!info.marshall)
-            return 0;           // type not registered with us
+            return nullptr;           // type not registered with us
     }
 
     // call to user code to construct the signature type
diff --git a/src/dbus/qdbusmisc.cpp b/src/dbus/qdbusmisc.cpp
index eb8f61c783..c321b7524d 100644
--- a/src/dbus/qdbusmisc.cpp
+++ b/src/dbus/qdbusmisc.cpp
@@ -62,7 +62,7 @@ bool qDBusCheckAsyncTag(const char *tag)
         return false;
 
     const char *p = strstr(tag, noReplyTag);
-    if (p != NULL &&
+    if (p != nullptr &&
         (p == tag || *(p-1) == ' ') &&
         (p[sizeof noReplyTag - 1] == '\0' || p[sizeof noReplyTag - 1] == ' '))
         return true;
@@ -167,7 +167,7 @@ int qDBusParametersForMethod(const QList<QByteArray> &parameterTypes, QVector<in
             if (id == 0) {
                 errorMsg = QLatin1String("Unregistered output type in parameter list: ") + QLatin1String(type);
                 return -1;
-            } else if (QDBusMetaType::typeToSignature(id) == 0)
+            } else if (QDBusMetaType::typeToSignature(id) == nullptr)
                 return -1;
 
             metaTypes.append( id );
@@ -195,7 +195,7 @@ int qDBusParametersForMethod(const QList<QByteArray> &parameterTypes, QVector<in
 
         if (id == QDBusMetaTypeId::message())
             seenMessage = true;
-        else if (QDBusMetaType::typeToSignature(id) == 0) {
+        else if (QDBusMetaType::typeToSignature(id) == nullptr) {
             errorMsg = QLatin1String("Type not registered with QtDBus in parameter list: ") + QLatin1String(type);
             return -1;
         }
diff --git a/src/dbus/qdbuspendingcall.cpp b/src/dbus/qdbuspendingcall.cpp
index 8e604d5a77..e55321f79c 100644
--- a/src/dbus/qdbuspendingcall.cpp
+++ b/src/dbus/qdbuspendingcall.cpp
@@ -182,7 +182,7 @@ bool QDBusPendingCallPrivate::setReplyCallback(QObject *target, const char *memb
     if (metaTypes.at(count) == QDBusMetaTypeId::message())
         --count;
 
-    setMetaTypes(count, count ? metaTypes.constData() + 1 : 0);
+    setMetaTypes(count, count ? metaTypes.constData() + 1 : nullptr);
     return true;
 }
 
@@ -469,10 +469,10 @@ QDBusPendingCall QDBusPendingCall::fromError(const QDBusError &error)
 */
 QDBusPendingCall QDBusPendingCall::fromCompletedCall(const QDBusMessage &msg)
 {
-    QDBusPendingCallPrivate *d = 0;
+    QDBusPendingCallPrivate *d = nullptr;
     if (msg.type() == QDBusMessage::ErrorMessage ||
         msg.type() == QDBusMessage::ReplyMessage) {
-        d = new QDBusPendingCallPrivate(QDBusMessage(), 0);
+        d = new QDBusPendingCallPrivate(QDBusMessage(), nullptr);
         d->replyMessage = msg;
         d->ref.storeRelaxed(1);
     }
diff --git a/src/dbus/qdbuspendingreply.cpp b/src/dbus/qdbuspendingreply.cpp
index ec49bafb60..cf13a134c5 100644
--- a/src/dbus/qdbuspendingreply.cpp
+++ b/src/dbus/qdbuspendingreply.cpp
@@ -247,7 +247,7 @@
 */
 
 QDBusPendingReplyData::QDBusPendingReplyData()
-    : QDBusPendingCall(0)         // initialize base class empty
+    : QDBusPendingCall(nullptr)         // initialize base class empty
 {
 }
 
@@ -262,7 +262,7 @@ void QDBusPendingReplyData::assign(const QDBusPendingCall &other)
 
 void QDBusPendingReplyData::assign(const QDBusMessage &message)
 {
-    d = new QDBusPendingCallPrivate(QDBusMessage(), 0); // drops the reference to the old one
+    d = new QDBusPendingCallPrivate(QDBusMessage(), nullptr); // drops the reference to the old one
     d->replyMessage = message;
 }
 
diff --git a/src/dbus/qdbusreply.cpp b/src/dbus/qdbusreply.cpp
index cf1a70508c..cd7193e02f 100644
--- a/src/dbus/qdbusreply.cpp
+++ b/src/dbus/qdbusreply.cpp
@@ -202,7 +202,7 @@ void qDBusReplyFill(const QDBusMessage &reply, QDBusError &error, QVariant &data
     }
 
     const char *expectedSignature = QDBusMetaType::typeToSignature(data.userType());
-    const char *receivedType = 0;
+    const char *receivedType = nullptr;
     QByteArray receivedSignature;
 
     if (reply.arguments().count() >= 1) {
diff --git a/src/dbus/qdbusunixfiledescriptor.cpp b/src/dbus/qdbusunixfiledescriptor.cpp
index 73d1db2680..87cabb93f6 100644
--- a/src/dbus/qdbusunixfiledescriptor.cpp
+++ b/src/dbus/qdbusunixfiledescriptor.cpp
@@ -135,7 +135,7 @@ QExplicitlySharedDataPointer<QDBusUnixFileDescriptorPrivate>::~QExplicitlyShared
     \sa fileDescriptor(), isValid()
 */
 QDBusUnixFileDescriptor::QDBusUnixFileDescriptor()
-    : d(0)
+    : d(nullptr)
 {
 }
 
@@ -153,7 +153,7 @@ QDBusUnixFileDescriptor::QDBusUnixFileDescriptor()
     \sa setFileDescriptor(), fileDescriptor()
 */
 QDBusUnixFileDescriptor::QDBusUnixFileDescriptor(int fileDescriptor)
-    : d(0)
+    : d(nullptr)
 {
     if (fileDescriptor != -1)
         setFileDescriptor(fileDescriptor);
diff --git a/src/dbus/qdbusutil.cpp b/src/dbus/qdbusutil.cpp
index dc94897ac4..09311d1ad4 100644
--- a/src/dbus/qdbusutil.cpp
+++ b/src/dbus/qdbusutil.cpp
@@ -246,12 +246,12 @@ static const char fixedTypes[] =         "ybnqiuxtdh";
 
 static bool isBasicType(int c)
 {
-    return c != DBUS_TYPE_INVALID && strchr(basicTypes, c) != NULL;
+    return c != DBUS_TYPE_INVALID && strchr(basicTypes, c) != nullptr;
 }
 
 static bool isFixedType(int c)
 {
-    return c != DBUS_TYPE_INVALID && strchr(fixedTypes, c) != NULL;
+    return c != DBUS_TYPE_INVALID && strchr(fixedTypes, c) != nullptr;
 }
 
 // Returns a pointer to one-past-end of this type if it's valid;
@@ -260,10 +260,10 @@ static const char *validateSingleType(const char *signature)
 {
     char c = *signature;
     if (c == DBUS_TYPE_INVALID)
-        return 0;
+        return nullptr;
 
     // is it one of the one-letter types?
-    if (strchr(oneLetterTypes, c) != NULL)
+    if (strchr(oneLetterTypes, c) != nullptr)
         return signature + 1;
 
     // is it an array?
@@ -277,9 +277,9 @@ static const char *validateSingleType(const char *signature)
             // and a free value
             c = *++signature;
             if (!isBasicType(c))
-                return 0;
+                return nullptr;
             signature = validateSingleType(signature + 1);
-            return signature && *signature == DBUS_DICT_ENTRY_END_CHAR ? signature + 1 : 0;
+            return signature && *signature == DBUS_DICT_ENTRY_END_CHAR ? signature + 1 : nullptr;
         }
 
         return validateSingleType(signature);
@@ -291,14 +291,14 @@ static const char *validateSingleType(const char *signature)
         while (true) {
             signature = validateSingleType(signature);
             if (!signature)
-                return 0;
+                return nullptr;
             if (*signature == DBUS_STRUCT_END_CHAR)
                 return signature + 1;
         }
     }
 
     // invalid/unknown type
-    return 0;
+    return nullptr;
 }
 
 /*!