Tidy nullptr usage

Move away from using 0 as pointer literal.

Done using clang-tidy. This is not complete as
run-clang-tidy can't handle all of qtbase in one go.

Change-Id: I1076a21f32aac0dab078af6f175f7508145eece0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

45 files changed, 194 insertions, 194 deletions

diff --git a/src/network/access/qabstractprotocolhandler.cpp b/src/network/access/qabstractprotocolhandler.cpp
index f15dfe6899..6847816ba7 100644
--- a/src/network/access/qabstractprotocolhandler.cpp
+++ b/src/network/access/qabstractprotocolhandler.cpp
@@ -43,7 +43,7 @@
 QT_BEGIN_NAMESPACE
 
 QAbstractProtocolHandler::QAbstractProtocolHandler(QHttpNetworkConnectionChannel *channel)
-    : m_channel(channel), m_reply(0), m_socket(m_channel->socket), m_connection(m_channel->connection)
+    : m_channel(channel), m_reply(nullptr), m_socket(m_channel->socket), m_connection(m_channel->connection)
 {
     Q_ASSERT(m_channel);
     Q_ASSERT(m_socket);
diff --git a/src/network/access/qftp.cpp b/src/network/access/qftp.cpp
index cc230a5411..62ae1adbd9 100644
--- a/src/network/access/qftp.cpp
+++ b/src/network/access/qftp.cpp
@@ -74,7 +74,7 @@ public:
         CsConnectionRefused
     };
 
-    QFtpDTP(QFtpPI *p, QObject *parent = 0);
+    QFtpDTP(QFtpPI *p, QObject *parent = nullptr);
 
     void setData(QByteArray *);
     void setDevice(QIODevice *);
@@ -149,7 +149,7 @@ class QFtpPI : public QObject
     Q_OBJECT
 
 public:
-    QFtpPI(QObject *parent = 0);
+    QFtpPI(QObject *parent = nullptr);
 
     void connectToHost(const QString &host, quint16 port);
 
@@ -229,7 +229,7 @@ class QFtpCommand
 {
 public:
     QFtpCommand(QFtp::Command cmd, const QStringList &raw, const QByteArray &ba);
-    QFtpCommand(QFtp::Command cmd, const QStringList &raw, QIODevice *dev = 0);
+    QFtpCommand(QFtp::Command cmd, const QStringList &raw, QIODevice *dev = nullptr);
     ~QFtpCommand();
 
     int id;
@@ -279,7 +279,7 @@ QFtpCommand::~QFtpCommand()
  *********************************************************************/
 QFtpDTP::QFtpDTP(QFtpPI *p, QObject *parent) :
     QObject(parent),
-    socket(0),
+    socket(nullptr),
     listener(this),
     pi(p),
     callWriteData(false)
@@ -314,7 +314,7 @@ void QFtpDTP::connectToHost(const QString & host, quint16 port)
 
     if (socket) {
         delete socket;
-        socket = 0;
+        socket = nullptr;
     }
     socket = new QTcpSocket(this);
 #ifndef QT_NO_BEARERMANAGEMENT
@@ -427,7 +427,7 @@ void QFtpDTP::writeData()
         }
 
         // do we continue uploading?
-        callWriteData = data.dev != 0;
+        callWriteData = data.dev != nullptr;
     }
 }
 
@@ -779,7 +779,7 @@ void QFtpDTP::setupSocket()
 void QFtpDTP::clearData()
 {
     is_ba = false;
-    data.dev = 0;
+    data.dev = nullptr;
 }
 
 /**********************************************************************
@@ -792,7 +792,7 @@ QFtpPI::QFtpPI(QObject *parent) :
     rawCommand(false),
     transferConnectionExtended(true),
     dtp(this),
-    commandSocket(0),
+    commandSocket(nullptr),
     state(Begin), abortState(None),
     currentCmd(QString()),
     waitForDtpToConnect(false),
@@ -2173,10 +2173,10 @@ QFtp::Command QFtp::currentCommand() const
 QIODevice* QFtp::currentDevice() const
 {
     if (d_func()->pending.isEmpty())
-        return 0;
+        return nullptr;
     QFtpCommand *c = d_func()->pending.first();
     if (c->is_ba)
-        return 0;
+        return nullptr;
     return c->data.dev;
 }
 
diff --git a/src/network/access/qhttpmultipart.cpp b/src/network/access/qhttpmultipart.cpp
index c59df9d8b8..d6fefc4314 100644
--- a/src/network/access/qhttpmultipart.cpp
+++ b/src/network/access/qhttpmultipart.cpp
@@ -111,7 +111,7 @@ QHttpPart::QHttpPart(const QHttpPart &other) : d(other.d)
 */
 QHttpPart::~QHttpPart()
 {
-    d = 0;
+    d = nullptr;
 }
 
 /*!
diff --git a/src/network/access/qhttpnetworkconnection.cpp b/src/network/access/qhttpnetworkconnection.cpp
index 21c6359807..b9a4c874c0 100644
--- a/src/network/access/qhttpnetworkconnection.cpp
+++ b/src/network/access/qhttpnetworkconnection.cpp
@@ -382,9 +382,9 @@ void QHttpNetworkConnectionPrivate::emitReplyError(QAbstractSocket *socket,
 
         // Clean the channel
         channels[i].close();
-        channels[i].reply = 0;
+        channels[i].reply = nullptr;
         if (channels[i].protocolHandler)
-            channels[i].protocolHandler->setReply(0);
+            channels[i].protocolHandler->setReply(nullptr);
         channels[i].request = QHttpNetworkRequest();
         if (socket)
             channels[i].requeueCurrentlyPipelinedRequests();
@@ -408,7 +408,7 @@ void QHttpNetworkConnectionPrivate::copyCredentials(int fromChannel, QAuthentica
     }
 
     // select another channel
-    QAuthenticator* otherAuth = 0;
+    QAuthenticator* otherAuth = nullptr;
     for (int i = 0; i < activeChannelCount; ++i) {
         if (i == fromChannel)
             continue;
@@ -441,7 +441,7 @@ bool QHttpNetworkConnectionPrivate::handleAuthenticateChallenge(QAbstractSocket
     if (authMethod != QAuthenticatorPrivate::None) {
         int i = indexOf(socket);
         //Use a single authenticator for all domains. ### change later to use domain/realm
-        QAuthenticator* auth = 0;
+        QAuthenticator* auth = nullptr;
         if (isProxy) {
             auth = &channels[i].proxyAuthenticator;
             channels[i].proxyAuthMethod = authMethod;
@@ -496,7 +496,7 @@ bool QHttpNetworkConnectionPrivate::handleAuthenticateChallenge(QAbstractSocket
         //   we need to bail out if authentication is required.
         if (priv->phase == QAuthenticatorPrivate::Done || !reply->request().withCredentials()) {
             // Reset authenticator so the next request on that channel does not get messed up
-            auth = 0;
+            auth = nullptr;
             if (isProxy)
                 channels[i].proxyAuthenticator = QAuthenticator();
             else
@@ -766,7 +766,7 @@ void QHttpNetworkConnectionPrivate::fillPipeline(QAbstractSocket *socket)
     int i = indexOf(socket);
 
     // return fast if there was no reply right now processed
-    if (channels[i].reply == 0)
+    if (channels[i].reply == nullptr)
         return;
 
     if (! (defaultPipelineLength - channels[i].alreadyPipelinedRequests.length() >= defaultRePipelineLength)) {
@@ -937,9 +937,9 @@ void QHttpNetworkConnectionPrivate::removeReply(QHttpNetworkReply *reply)
     for (int i = 0; i < activeChannelCount; ++i) {
         // is the reply associated the currently processing of this channel?
         if (channels[i].reply == reply) {
-            channels[i].reply = 0;
+            channels[i].reply = nullptr;
             if (channels[i].protocolHandler)
-                channels[i].protocolHandler->setReply(0);
+                channels[i].protocolHandler->setReply(nullptr);
             channels[i].request = QHttpNetworkRequest();
             channels[i].resendCurrent = false;
 
diff --git a/src/network/access/qhttpnetworkconnectionchannel.cpp b/src/network/access/qhttpnetworkconnectionchannel.cpp
index 39f392a79b..47081b29d2 100644
--- a/src/network/access/qhttpnetworkconnectionchannel.cpp
+++ b/src/network/access/qhttpnetworkconnectionchannel.cpp
@@ -87,11 +87,11 @@ private:
 static const int reconnectAttemptsDefault = 3;
 
 QHttpNetworkConnectionChannel::QHttpNetworkConnectionChannel()
-    : socket(0)
+    : socket(nullptr)
     , ssl(false)
     , isInitialized(false)
     , state(IdleState)
-    , reply(0)
+    , reply(nullptr)
     , written(0)
     , bytesTotal(0)
     , resendCurrent(false)
@@ -102,13 +102,13 @@ QHttpNetworkConnectionChannel::QHttpNetworkConnectionChannel()
     , proxyAuthMethod(QAuthenticatorPrivate::None)
     , authenticationCredentialsSent(false)
     , proxyCredentialsSent(false)
-    , protocolHandler(0)
+    , protocolHandler(nullptr)
 #ifndef QT_NO_SSL
     , ignoreAllSslErrors(false)
 #endif
     , pipeliningSupported(PipeliningSupportUnknown)
     , networkLayerPreference(QAbstractSocket::AnyIPProtocol)
-    , connection(0)
+    , connection(nullptr)
 {
     // Inlining this function in the header leads to compiler error on
     // release-armv5, on at least timebox 9.2 and 10.1.
@@ -295,9 +295,9 @@ void QHttpNetworkConnectionChannel::handleUnexpectedEOF()
         close();
         reply->d_func()->errorString = connection->d_func()->errorDetail(QNetworkReply::RemoteHostClosedError, socket);
         emit reply->finishedWithError(QNetworkReply::RemoteHostClosedError, reply->d_func()->errorString);
-        reply = 0;
+        reply = nullptr;
         if (protocolHandler)
-            protocolHandler->setReply(0);
+            protocolHandler->setReply(nullptr);
         request = QHttpNetworkRequest();
         QMetaObject::invokeMethod(connection, "_q_startNextRequest", Qt::QueuedConnection);
     } else {
@@ -526,8 +526,8 @@ void QHttpNetworkConnectionChannel::allDone()
     // problem.
     if (!resendCurrent) {
         request = QHttpNetworkRequest();
-        reply = 0;
-        protocolHandler->setReply(0);
+        reply = nullptr;
+        protocolHandler->setReply(nullptr);
     }
 
     // move next from pipeline to current request
@@ -1100,9 +1100,9 @@ void QHttpNetworkConnectionChannel::_q_error(QAbstractSocket::SocketError socket
         if (reply) {
             reply->d_func()->errorString = errorString;
             emit reply->finishedWithError(errorCode, errorString);
-            reply = 0;
+            reply = nullptr;
             if (protocolHandler)
-                protocolHandler->setReply(0);
+                protocolHandler->setReply(nullptr);
         }
     } while (!connection->d_func()->highPriorityQueue.isEmpty()
              || !connection->d_func()->lowPriorityQueue.isEmpty());
diff --git a/src/network/access/qhttpnetworkreply.cpp b/src/network/access/qhttpnetworkreply.cpp
index a8b635c45a..af456c3607 100644
--- a/src/network/access/qhttpnetworkreply.cpp
+++ b/src/network/access/qhttpnetworkreply.cpp
@@ -330,12 +330,12 @@ QHttpNetworkReplyPrivate::QHttpNetworkReplyPrivate(const QUrl &newUrl)
       currentlyUploadedDataInWindow(0),
       totallyUploadedData(0),
       removedContentLength(-1),
-      connection(0),
+      connection(nullptr),
       autoDecompress(false), responseData(), requestIsPrepared(false)
       ,pipeliningUsed(false), spdyUsed(false), downstreamLimited(false)
-      ,userProvidedDownloadBuffer(0)
+      ,userProvidedDownloadBuffer(nullptr)
 #ifndef QT_NO_COMPRESS
-      ,inflateStrm(0)
+      ,inflateStrm(nullptr)
 #endif
 
 {
@@ -375,8 +375,8 @@ void QHttpNetworkReplyPrivate::clearHttpLayerInformation()
 // TODO: Isn't everything HTTP layer related? We don't need to set connection and connectionChannel to 0 at all
 void QHttpNetworkReplyPrivate::clear()
 {
-    connection = 0;
-    connectionChannel = 0;
+    connection = nullptr;
+    connectionChannel = nullptr;
     autoDecompress = false;
     clearHttpLayerInformation();
 }
diff --git a/src/network/access/qhttpnetworkrequest.cpp b/src/network/access/qhttpnetworkrequest.cpp
index a3f71b8d2f..5fb8885bdf 100644
--- a/src/network/access/qhttpnetworkrequest.cpp
+++ b/src/network/access/qhttpnetworkrequest.cpp
@@ -44,7 +44,7 @@ QT_BEGIN_NAMESPACE
 
 QHttpNetworkRequestPrivate::QHttpNetworkRequestPrivate(QHttpNetworkRequest::Operation op,
         QHttpNetworkRequest::Priority pri, const QUrl &newUrl)
-    : QHttpNetworkHeaderPrivate(newUrl), operation(op), priority(pri), uploadByteDevice(0),
+    : QHttpNetworkHeaderPrivate(newUrl), operation(op), priority(pri), uploadByteDevice(nullptr),
       autoDecompress(false), pipeliningAllowed(false), spdyAllowed(false), http2Allowed(false),
       http2Direct(false), withCredentials(true), preConnect(false), redirectCount(0),
       redirectPolicy(QNetworkRequest::ManualRedirectPolicy)
diff --git a/src/network/access/qhttpprotocolhandler.cpp b/src/network/access/qhttpprotocolhandler.cpp
index edcbdcbe0e..d39589fb96 100644
--- a/src/network/access/qhttpprotocolhandler.cpp
+++ b/src/network/access/qhttpprotocolhandler.cpp
@@ -278,7 +278,7 @@ bool QHttpProtocolHandler::sendRequest()
             m_reply->d_func()->state = QHttpNetworkReplyPrivate::AllDoneState;
             m_channel->allDone();
             m_connection->preConnectFinished(); // will only decrease the counter
-            m_reply = 0; // so we can reuse this channel
+            m_reply = nullptr; // so we can reuse this channel
             return true; // we have a working connection and are done
         }
 
@@ -373,7 +373,7 @@ bool QHttpProtocolHandler::sendRequest()
                 // premature eof happened
                 m_connection->d_func()->emitReplyError(m_socket, m_reply, QNetworkReply::UnknownNetworkError);
                 return false;
-            } else if (readPointer == 0 || currentReadSize == 0) {
+            } else if (readPointer == nullptr || currentReadSize == 0) {
                 // nothing to read currently, break the loop
                 break;
             } else {
diff --git a/src/network/access/qhttpthreaddelegate.cpp b/src/network/access/qhttpthreaddelegate.cpp
index 63a3c4f204..f3125a3a95 100644
--- a/src/network/access/qhttpthreaddelegate.cpp
+++ b/src/network/access/qhttpthreaddelegate.cpp
@@ -189,7 +189,7 @@ public:
     QNetworkAccessCachedHttpConnection(const QString &hostName, quint16 port, bool encrypt,
                                        QHttpNetworkConnection::ConnectionType connectionType,
                                        QSharedPointer<QNetworkSession> networkSession)
-        : QHttpNetworkConnection(hostName, port, encrypt, connectionType, /*parent=*/0,
+        : QHttpNetworkConnection(hostName, port, encrypt, connectionType, /*parent=*/nullptr,
                                  std::move(networkSession))
 #endif
     {
@@ -241,9 +241,9 @@ QHttpThreadDelegate::QHttpThreadDelegate(QObject *parent) :
     , removedContentLength(-1)
     , incomingErrorCode(QNetworkReply::NoError)
     , downloadBuffer()
-    , httpConnection(0)
-    , httpReply(0)
-    , synchronousRequestLoop(0)
+    , httpConnection(nullptr)
+    , httpReply(nullptr)
+    , synchronousRequestLoop(nullptr)
 {
 }
 
@@ -439,7 +439,7 @@ void QHttpThreadDelegate::abortRequest()
     if (httpReply) {
         httpReply->abort();
         delete httpReply;
-        httpReply = 0;
+        httpReply = nullptr;
     }
 
     // Got aborted by the timeout timer
@@ -545,7 +545,7 @@ void QHttpThreadDelegate::finishedSlot()
 
     QMetaObject::invokeMethod(httpReply, "deleteLater", Qt::QueuedConnection);
     QMetaObject::invokeMethod(this, "deleteLater", Qt::QueuedConnection);
-    httpReply = 0;
+    httpReply = nullptr;
 }
 
 void QHttpThreadDelegate::synchronousFinishedSlot()
@@ -568,7 +568,7 @@ void QHttpThreadDelegate::synchronousFinishedSlot()
 
     QMetaObject::invokeMethod(httpReply, "deleteLater", Qt::QueuedConnection);
     QMetaObject::invokeMethod(synchronousRequestLoop, "quit", Qt::QueuedConnection);
-    httpReply = 0;
+    httpReply = nullptr;
 }
 
 void QHttpThreadDelegate::finishedWithErrorSlot(QNetworkReply::NetworkError errorCode, const QString &detail)
@@ -590,7 +590,7 @@ void QHttpThreadDelegate::finishedWithErrorSlot(QNetworkReply::NetworkError erro
 
     QMetaObject::invokeMethod(httpReply, "deleteLater", Qt::QueuedConnection);
     QMetaObject::invokeMethod(this, "deleteLater", Qt::QueuedConnection);
-    httpReply = 0;
+    httpReply = nullptr;
 }
 
 
@@ -609,7 +609,7 @@ void QHttpThreadDelegate::synchronousFinishedWithErrorSlot(QNetworkReply::Networ
 
     QMetaObject::invokeMethod(httpReply, "deleteLater", Qt::QueuedConnection);
     QMetaObject::invokeMethod(synchronousRequestLoop, "quit", Qt::QueuedConnection);
-    httpReply = 0;
+    httpReply = nullptr;
 }
 
 static void downloadBufferDeleter(char *ptr)
diff --git a/src/network/access/qnetworkaccessauthenticationmanager.cpp b/src/network/access/qnetworkaccessauthenticationmanager.cpp
index b661cc45b3..0df11684b1 100644
--- a/src/network/access/qnetworkaccessauthenticationmanager.cpp
+++ b/src/network/access/qnetworkaccessauthenticationmanager.cpp
@@ -71,7 +71,7 @@ public:
         if (it == end() && !isEmpty())
             --it;
         if (it == end() || !domain.startsWith(it->domain))
-            return 0;
+            return nullptr;
         return &*it;
     }
 
diff --git a/src/network/access/qnetworkaccessbackend.cpp b/src/network/access/qnetworkaccessbackend.cpp
index 566e410051..8f42f3690b 100644
--- a/src/network/access/qnetworkaccessbackend.cpp
+++ b/src/network/access/qnetworkaccessbackend.cpp
@@ -105,7 +105,7 @@ QNetworkAccessBackend *QNetworkAccessManagerPrivate::findBackend(QNetworkAccessM
             ++it;
         }
     }
-    return 0;
+    return nullptr;
 }
 
 QStringList QNetworkAccessManagerPrivate::backendSupportedSchemes() const
@@ -131,7 +131,7 @@ QNonContiguousByteDevice* QNetworkAccessBackend::createUploadByteDevice()
     else if (reply->outgoingData) {
         uploadByteDevice = QNonContiguousByteDeviceFactory::createShared(reply->outgoingData);
     } else {
-        return 0;
+        return nullptr;
     }
 
     // We want signal emissions only for normal asynchronous uploads
@@ -151,8 +151,8 @@ void QNetworkAccessBackend::emitReplyUploadProgress(qint64 bytesSent, qint64 byt
 }
 
 QNetworkAccessBackend::QNetworkAccessBackend()
-    : manager(0)
-    , reply(0)
+    : manager(nullptr)
+    , reply(nullptr)
     , synchronous(false)
 {
 }
@@ -223,7 +223,7 @@ QList<QNetworkProxy> QNetworkAccessBackend::proxyList() const
 QAbstractNetworkCache *QNetworkAccessBackend::networkCache() const
 {
     if (!manager)
-        return 0;
+        return nullptr;
     return manager->networkCache;
 }
 
diff --git a/src/network/access/qnetworkaccesscache.cpp b/src/network/access/qnetworkaccesscache.cpp
index b694a2c999..ba092f2618 100644
--- a/src/network/access/qnetworkaccesscache.cpp
+++ b/src/network/access/qnetworkaccesscache.cpp
@@ -73,7 +73,7 @@ struct QNetworkAccessCache::Node
     int useCount;
 
     Node()
-        : older(0), newer(0), object(0), useCount(0)
+        : older(nullptr), newer(nullptr), object(nullptr), useCount(0)
     { }
 };
 
@@ -103,7 +103,7 @@ void QNetworkAccessCache::CacheableObject::setShareable(bool enable)
 }
 
 QNetworkAccessCache::QNetworkAccessCache()
-    : oldest(0), newest(0)
+    : oldest(nullptr), newest(nullptr)
 {
 }
 
@@ -130,7 +130,7 @@ void QNetworkAccessCache::clear()
 
     timer.stop();
 
-    oldest = newest = 0;
+    oldest = newest = nullptr;
 }
 
 /*!
@@ -145,11 +145,11 @@ void QNetworkAccessCache::linkEntry(const QByteArray &key)
 
     Node *const node = &it.value();
     Q_ASSERT(node != oldest && node != newest);
-    Q_ASSERT(node->older == 0 && node->newer == 0);
+    Q_ASSERT(node->older == nullptr && node->newer == nullptr);
     Q_ASSERT(node->useCount == 0);
 
     if (newest) {
-        Q_ASSERT(newest->newer == 0);
+        Q_ASSERT(newest->newer == nullptr);
         newest->newer = node;
         node->older = newest;
     }
@@ -186,7 +186,7 @@ bool QNetworkAccessCache::unlinkEntry(const QByteArray &key)
     if (node->newer)
         node->newer->older = node->older;
 
-    node->newer = node->older = 0;
+    node->newer = node->older = nullptr;
     return wasOldest;
 }
 
@@ -235,9 +235,9 @@ void QNetworkAccessCache::timerEvent(QTimerEvent *)
 
     // fixup the list
     if (oldest)
-        oldest->older = 0;
+        oldest->older = nullptr;
     else
-        newest = 0;
+        newest = nullptr;
 
     updateTimer();
 }
@@ -277,7 +277,7 @@ bool QNetworkAccessCache::requestEntry(const QByteArray &key, QObject *target, c
     if (node->useCount > 0 && !node->object->shareable) {
         // object is not shareable and is in use
         // queue for later use
-        Q_ASSERT(node->older == 0 && node->newer == 0);
+        Q_ASSERT(node->older == nullptr && node->newer == nullptr);
         node->receiverQueue.push_back({target, member});
 
         // request queued
@@ -296,7 +296,7 @@ QNetworkAccessCache::CacheableObject *QNetworkAccessCache::requestEntryNow(const
 {
     NodeHash::Iterator it = hash.find(key);
     if (it == hash.end())
-        return 0;
+        return nullptr;
     if (it->useCount > 0) {
         if (it->object->shareable) {
             ++it->useCount;
@@ -304,7 +304,7 @@ QNetworkAccessCache::CacheableObject *QNetworkAccessCache::requestEntryNow(const
         }
 
         // object in use and not shareable
-        return 0;
+        return nullptr;
     }
 
     // entry not in use, let the caller have it
diff --git a/src/network/access/qnetworkaccessdebugpipebackend.cpp b/src/network/access/qnetworkaccessdebugpipebackend.cpp
index 67a856506c..03ffc69628 100644
--- a/src/network/access/qnetworkaccessdebugpipebackend.cpp
+++ b/src/network/access/qnetworkaccessdebugpipebackend.cpp
@@ -70,13 +70,13 @@ QNetworkAccessDebugPipeBackendFactory::create(QNetworkAccessManager::Operation o
 
     default:
         // no, we can't handle this operation
-        return 0;
+        return nullptr;
     }
 
     QUrl url = request.url();
     if (url.scheme() == QLatin1String("debugpipe"))
         return new QNetworkAccessDebugPipeBackend;
-    return 0;
+    return nullptr;
 }
 
 QNetworkAccessDebugPipeBackend::QNetworkAccessDebugPipeBackend()
@@ -188,7 +188,7 @@ void QNetworkAccessDebugPipeBackend::pushFromUpstreamToSocket()
                 emitReplyUploadProgress(bytesUploaded, bytesUploaded);
                 possiblyFinish();
                 break;
-            } else if (haveRead == 0 || readPointer == 0) {
+            } else if (haveRead == 0 || readPointer == nullptr) {
                 // nothing to read right now, we will be called again later
                 break;
             } else {
diff --git a/src/network/access/qnetworkaccessfilebackend.cpp b/src/network/access/qnetworkaccessfilebackend.cpp
index 60353cb03e..507417f86c 100644
--- a/src/network/access/qnetworkaccessfilebackend.cpp
+++ b/src/network/access/qnetworkaccessfilebackend.cpp
@@ -73,7 +73,7 @@ QNetworkAccessFileBackendFactory::create(QNetworkAccessManager::Operation op,
 
     default:
         // no, we can't handle this operation
-        return 0;
+        return nullptr;
     }
 
     QUrl url = request.url();
@@ -95,7 +95,7 @@ QNetworkAccessFileBackendFactory::create(QNetworkAccessManager::Operation op,
             return new QNetworkAccessFileBackend;
     }
 
-    return 0;
+    return nullptr;
 }
 
 QNetworkAccessFileBackend::QNetworkAccessFileBackend()
@@ -198,7 +198,7 @@ void QNetworkAccessFileBackend::uploadReadyReadSlot()
             file.close();
             finished();
             break;
-        } else if (haveRead == 0 || readPointer == 0) {
+        } else if (haveRead == 0 || readPointer == nullptr) {
             // nothing to read right now, we will be called again later
             break;
         } else {
diff --git a/src/network/access/qnetworkaccessftpbackend.cpp b/src/network/access/qnetworkaccessftpbackend.cpp
index 51ed2f5a55..fb8cd79c12 100644
--- a/src/network/access/qnetworkaccessftpbackend.cpp
+++ b/src/network/access/qnetworkaccessftpbackend.cpp
@@ -75,13 +75,13 @@ QNetworkAccessFtpBackendFactory::create(QNetworkAccessManager::Operation op,
 
     default:
         // no, we can't handle this operation
-        return 0;
+        return nullptr;
     }
 
     QUrl url = request.url();
     if (url.scheme().compare(QLatin1String("ftp"), Qt::CaseInsensitive) == 0)
         return new QNetworkAccessFtpBackend;
-    return 0;
+    return nullptr;
 }
 
 class QNetworkAccessCachedFtpConnection: public QFtp, public QNetworkAccessCache::CacheableObject
@@ -104,7 +104,7 @@ public:
 };
 
 QNetworkAccessFtpBackend::QNetworkAccessFtpBackend()
-    : ftp(0), uploadDevice(0), totalBytes(0), helpId(-1), sizeId(-1), mdtmId(-1), pwdId(-1),
+    : ftp(nullptr), uploadDevice(nullptr), totalBytes(0), helpId(-1), sizeId(-1), mdtmId(-1), pwdId(-1),
     supportsSize(false), supportsMdtm(false), supportsPwd(false), state(Idle)
 {
 }
@@ -215,7 +215,7 @@ void QNetworkAccessFtpBackend::disconnectFromFtp(CacheCleanupMode mode)
     state = Disconnecting;
 
     if (ftp) {
-        disconnect(ftp, 0, this, 0);
+        disconnect(ftp, nullptr, this, nullptr);
 
         QByteArray key = makeCacheKey(url());
         if (mode == RemoveCachedConnection) {
@@ -225,7 +225,7 @@ void QNetworkAccessFtpBackend::disconnectFromFtp(CacheCleanupMode mode)
             QNetworkAccessManagerPrivate::getObjectCache(this)->releaseEntry(key);
         }
 
-        ftp = 0;
+        ftp = nullptr;
     }
 }
 
@@ -362,7 +362,7 @@ void QNetworkAccessFtpBackend::ftpDone()
         QFtp::TransferType type = QFtp::Binary;
         if (operation() == QNetworkAccessManager::GetOperation) {
             setCachingEnabled(true);
-            ftp->get(url().path(), 0, type);
+            ftp->get(url().path(), nullptr, type);
         } else {
             ftp->put(uploadDevice, url().path(), type);
         }
diff --git a/src/network/access/qnetworkcookie.cpp b/src/network/access/qnetworkcookie.cpp
index 903de322ff..47f6112b22 100644
--- a/src/network/access/qnetworkcookie.cpp
+++ b/src/network/access/qnetworkcookie.cpp
@@ -131,7 +131,7 @@ QNetworkCookie::QNetworkCookie(const QNetworkCookie &other)
 QNetworkCookie::~QNetworkCookie()
 {
     // QSharedDataPointer auto deletes
-    d = 0;
+    d = nullptr;
 }
 
 /*!
diff --git a/src/network/access/qnetworkdiskcache.cpp b/src/network/access/qnetworkdiskcache.cpp
index df2e4902a4..b30d1c9664 100644
--- a/src/network/access/qnetworkdiskcache.cpp
+++ b/src/network/access/qnetworkdiskcache.cpp
@@ -180,11 +180,11 @@ QIODevice *QNetworkDiskCache::prepare(const QNetworkCacheMetaData &metaData)
 #endif
     Q_D(QNetworkDiskCache);
     if (!metaData.isValid() || !metaData.url().isValid() || !metaData.saveToDisk())
-        return 0;
+        return nullptr;
 
     if (d->cacheDirectory.isEmpty()) {
         qWarning("QNetworkDiskCache::prepare() The cache directory is not set");
-        return 0;
+        return nullptr;
     }
 
     const auto headers = metaData.rawHeaders();
@@ -192,14 +192,14 @@ QIODevice *QNetworkDiskCache::prepare(const QNetworkCacheMetaData &metaData)
         if (header.first.compare("content-length", Qt::CaseInsensitive) == 0) {
             const qint64 size = header.second.toLongLong();
             if (size > (maximumCacheSize() * 3)/4)
-                return 0;
+                return nullptr;
             break;
         }
     }
     QScopedPointer<QCacheItem> cacheItem(new QCacheItem);
     cacheItem->metaData = metaData;
 
-    QIODevice *device = 0;
+    QIODevice *device = nullptr;
     if (cacheItem->canCompress()) {
         cacheItem->data.open(QBuffer::ReadWrite);
         device = &(cacheItem->data);
@@ -208,12 +208,12 @@ QIODevice *QNetworkDiskCache::prepare(const QNetworkCacheMetaData &metaData)
         QT_TRY {
             cacheItem->file = new QTemporaryFile(templateName, &cacheItem->data);
         } QT_CATCH(...) {
-            cacheItem->file = 0;
+            cacheItem->file = nullptr;
         }
         if (!cacheItem->file || !cacheItem->file->open()) {
             qWarning("QNetworkDiskCache::prepare() unable to open temporary file");
             cacheItem.reset();
-            return 0;
+            return nullptr;
         }
         cacheItem->writeHeader(cacheItem->file);
         device = cacheItem->file;
@@ -397,19 +397,19 @@ QIODevice *QNetworkDiskCache::data(const QUrl &url)
     Q_D(QNetworkDiskCache);
     QScopedPointer<QBuffer> buffer;
     if (!url.isValid())
-        return 0;
+        return nullptr;
     if (d->lastItem.metaData.url() == url && d->lastItem.data.isOpen()) {
         buffer.reset(new QBuffer);
         buffer->setData(d->lastItem.data.data());
     } else {
         QScopedPointer<QFile> file(new QFile(d->cacheFileName(url)));
         if (!file->open(QFile::ReadOnly | QIODevice::Unbuffered))
-            return 0;
+            return nullptr;
 
         if (!d->lastItem.read(file.data(), true)) {
             file->close();
             remove(url);
-            return 0;
+            return nullptr;
         }
         if (d->lastItem.data.isOpen()) {
             // compressed
@@ -419,7 +419,7 @@ QIODevice *QNetworkDiskCache::data(const QUrl &url)
             buffer.reset(new QBuffer);
             // ### verify that QFile uses the fd size and not the file name
             qint64 size = file->size() - file->pos();
-            const uchar *p = 0;
+            const uchar *p = nullptr;
 #if !defined(Q_OS_INTEGRITY)
             p = file->map(file->pos(), size);
 #endif
@@ -557,7 +557,7 @@ qint64 QNetworkDiskCache::expire()
             for (QCacheItem *item : qAsConst(d->inserting)) {
                 if (item && item->file && item->file->fileName() == name) {
                     delete item->file;
-                    item->file = 0;
+                    item->file = nullptr;
                     break;
                 }
             }
diff --git a/src/network/access/qnetworkreplyfileimpl.cpp b/src/network/access/qnetworkreplyfileimpl.cpp
index ef319ebf0d..afab8ffd94 100644
--- a/src/network/access/qnetworkreplyfileimpl.cpp
+++ b/src/network/access/qnetworkreplyfileimpl.cpp
@@ -50,7 +50,7 @@
 QT_BEGIN_NAMESPACE
 
 QNetworkReplyFileImplPrivate::QNetworkReplyFileImplPrivate()
-    : QNetworkReplyPrivate(), managerPrivate(0), realFile(0)
+    : QNetworkReplyPrivate(), managerPrivate(nullptr), realFile(nullptr)
 {
     qRegisterMetaType<QNetworkRequest::KnownHeaders>();
     qRegisterMetaType<QNetworkReply::NetworkError>();
diff --git a/src/network/access/qnetworkreplyimpl.cpp b/src/network/access/qnetworkreplyimpl.cpp
index 6eab500e8c..a43a29a239 100644
--- a/src/network/access/qnetworkreplyimpl.cpp
+++ b/src/network/access/qnetworkreplyimpl.cpp
@@ -53,9 +53,9 @@
 QT_BEGIN_NAMESPACE
 
 inline QNetworkReplyImplPrivate::QNetworkReplyImplPrivate()
-    : backend(0), outgoingData(0),
-      copyDevice(0),
-      cacheEnabled(false), cacheSaveDevice(0),
+    : backend(nullptr), outgoingData(nullptr),
+      copyDevice(nullptr),
+      cacheEnabled(false), cacheSaveDevice(nullptr),
       notificationHandlingPaused(false),
       bytesDownloaded(0), lastBytesDownloaded(-1), bytesUploaded(-1), preMigrationDownloaded(-1),
       httpStatusCode(0),
@@ -63,7 +63,7 @@ inline QNetworkReplyImplPrivate::QNetworkReplyImplPrivate()
       , downloadBufferReadPosition(0)
       , downloadBufferCurrentSize(0)
       , downloadBufferMaximumSize(0)
-      , downloadBuffer(0)
+      , downloadBuffer(nullptr)
 {
     if (request.attribute(QNetworkRequest::EmitAllUploadProgressSignalsAttribute).toBool() == true)
         emitAllUploadProgressSignals = true;
@@ -489,7 +489,7 @@ void QNetworkReplyImplPrivate::resumeNotificationHandling()
 QAbstractNetworkCache *QNetworkReplyImplPrivate::networkCache() const
 {
     if (!backend)
-        return 0;
+        return nullptr;
     return backend->networkCache();
 }
 
@@ -504,7 +504,7 @@ void QNetworkReplyImplPrivate::createCache()
 
 bool QNetworkReplyImplPrivate::isCachingEnabled() const
 {
-    return (cacheEnabled && networkCache() != 0);
+    return (cacheEnabled && networkCache() != nullptr);
 }
 
 void QNetworkReplyImplPrivate::setCachingEnabled(bool enable)
@@ -529,7 +529,7 @@ void QNetworkReplyImplPrivate::setCachingEnabled(bool enable)
                "backend %s probably needs to be fixed",
                backend->metaObject()->className());
         networkCache()->remove(url);
-        cacheSaveDevice = 0;
+        cacheSaveDevice = nullptr;
         cacheEnabled = false;
     }
 }
@@ -541,7 +541,7 @@ void QNetworkReplyImplPrivate::completeCacheSave()
     } else if (cacheEnabled && cacheSaveDevice) {
         networkCache()->insert(cacheSaveDevice);
     }
-    cacheSaveDevice = 0;
+    cacheSaveDevice = nullptr;
     cacheEnabled = false;
 }
 
@@ -610,7 +610,7 @@ void QNetworkReplyImplPrivate::initCacheSaveDevice()
                   networkCache()->metaObject()->className());
 
         networkCache()->remove(url);
-        cacheSaveDevice = 0;
+        cacheSaveDevice = nullptr;
         cacheEnabled = false;
     }
 }
@@ -927,9 +927,9 @@ void QNetworkReplyImpl::abort()
 
     // stop both upload and download
     if (d->outgoingData)
-        disconnect(d->outgoingData, 0, this, 0);
+        disconnect(d->outgoingData, nullptr, this, nullptr);
     if (d->copyDevice)
-        disconnect(d->copyDevice, 0, this, 0);
+        disconnect(d->copyDevice, nullptr, this, nullptr);
 
     QNetworkReply::close();
 
@@ -943,7 +943,7 @@ void QNetworkReplyImpl::abort()
     // finished may access the backend
     if (d->backend) {
         d->backend->deleteLater();
-        d->backend = 0;
+        d->backend = nullptr;
     }
 }
 
@@ -958,7 +958,7 @@ void QNetworkReplyImpl::close()
     if (d->backend)
         d->backend->closeDownstreamChannel();
     if (d->copyDevice)
-        disconnect(d->copyDevice, 0, this, 0);
+        disconnect(d->copyDevice, nullptr, this, nullptr);
 
     QNetworkReply::close();
 
diff --git a/src/network/access/qnetworkrequest.cpp b/src/network/access/qnetworkrequest.cpp
index 92e5aed38c..70b09dba22 100644
--- a/src/network/access/qnetworkrequest.cpp
+++ b/src/network/access/qnetworkrequest.cpp
@@ -444,7 +444,7 @@ public:
     inline QNetworkRequestPrivate()
         : priority(QNetworkRequest::NormalPriority)
 #ifndef QT_NO_SSL
-        , sslConfiguration(0)
+        , sslConfiguration(nullptr)
 #endif
         , maxRedirectsAllowed(maxRedirectCount)
         , transferTimeout(0)
@@ -464,7 +464,7 @@ public:
         priority = other.priority;
         maxRedirectsAllowed = other.maxRedirectsAllowed;
 #ifndef QT_NO_SSL
-        sslConfiguration = 0;
+        sslConfiguration = nullptr;
         if (other.sslConfiguration)
             sslConfiguration = new QSslConfiguration(*other.sslConfiguration);
 #endif
@@ -550,7 +550,7 @@ QNetworkRequest::QNetworkRequest(const QNetworkRequest &other)
 QNetworkRequest::~QNetworkRequest()
 {
     // QSharedDataPointer auto deletes
-    d = 0;
+    d = nullptr;
 }
 
 /*!
diff --git a/src/network/access/qspdyprotocolhandler.cpp b/src/network/access/qspdyprotocolhandler.cpp
index cc913ce760..eef8df288d 100644
--- a/src/network/access/qspdyprotocolhandler.cpp
+++ b/src/network/access/qspdyprotocolhandler.cpp
@@ -254,7 +254,7 @@ static const char spdyDictionary[] = {
 //}
 
 QSpdyProtocolHandler::QSpdyProtocolHandler(QHttpNetworkConnectionChannel *channel)
-    : QObject(0), QAbstractProtocolHandler(channel),
+    : QObject(nullptr), QAbstractProtocolHandler(channel),
       m_nextStreamID(-1),
       m_maxConcurrentStreams(100), // 100 is recommended in the SPDY RFC
       m_initialWindowSize(0),
@@ -720,7 +720,7 @@ bool QSpdyProtocolHandler::uploadData(qint32 streamID)
             m_connection->d_func()->emitReplyError(m_socket, reply,
                                                    QNetworkReply::UnknownNetworkError);
             return false;
-        } else if (readPointer == 0 || currentReadSize == 0) {
+        } else if (readPointer == nullptr || currentReadSize == 0) {
             // nothing to read currently, break the loop
             break;
         } else {
@@ -746,7 +746,7 @@ bool QSpdyProtocolHandler::uploadData(qint32 streamID)
     }
     if (replyPrivate->totallyUploadedData == request.contentLength()) {
         DataFrameFlags finFlag = DataFrame_FLAG_FIN;
-        qint64 writeSize = sendDataFrame(streamID, finFlag, 0, 0);
+        qint64 writeSize = sendDataFrame(streamID, finFlag, 0, nullptr);
         Q_ASSERT(writeSize == 0);
         Q_UNUSED(writeSize); // silence -Wunused-variable
         replyPrivate->state = QHttpNetworkReplyPrivate::SPDYHalfClosed;
@@ -892,7 +892,7 @@ void QSpdyProtocolHandler::parseHttpHeaders(char flags, const QByteArray &frameD
 
     HttpMessagePair pair = it.value();
     QHttpNetworkReply *httpReply = pair.second;
-    Q_ASSERT(httpReply != 0);
+    Q_ASSERT(httpReply != nullptr);
 
     if (httpReply->d_func()->state == QHttpNetworkReplyPrivate::SPDYClosed) {
         sendRST_STREAM(streamID, RST_STREAM_STREAM_ALREADY_CLOSED);
@@ -950,7 +950,7 @@ void QSpdyProtocolHandler::parseHttpHeaders(char flags, const QByteArray &frameD
 
     if (flag_fin) {
         if (httpReply->d_func()->state != QHttpNetworkReplyPrivate::SPDYHalfClosed)
-            sendDataFrame(streamID, DataFrame_FLAG_FIN, 0, 0);
+            sendDataFrame(streamID, DataFrame_FLAG_FIN, 0, nullptr);
         replyFinished(httpReply, streamID);
     }
 }
@@ -1199,7 +1199,7 @@ void QSpdyProtocolHandler::handleDataFrame(const QByteArray &frameHeaders)
     HttpMessagePair pair = it.value();
     QHttpNetworkRequest httpRequest = pair.first;
     QHttpNetworkReply *httpReply = pair.second;
-    Q_ASSERT(httpReply != 0);
+    Q_ASSERT(httpReply != nullptr);
 
     QHttpNetworkReplyPrivate *replyPrivate = httpReply->d_func();
 
@@ -1261,7 +1261,7 @@ void QSpdyProtocolHandler::handleDataFrame(const QByteArray &frameHeaders)
 
     if (flag_fin) {
         if (httpReply->d_func()->state != QHttpNetworkReplyPrivate::SPDYHalfClosed)
-            sendDataFrame(streamID, DataFrame_FLAG_FIN, 0, 0);
+            sendDataFrame(streamID, DataFrame_FLAG_FIN, 0, nullptr);
         replyFinished(httpReply, streamID);
     }
 }
diff --git a/src/network/bearer/qnetworkconfigmanager.cpp b/src/network/bearer/qnetworkconfigmanager.cpp
index c2d30d52e2..751735c8bd 100644
--- a/src/network/bearer/qnetworkconfigmanager.cpp
+++ b/src/network/bearer/qnetworkconfigmanager.cpp
@@ -68,7 +68,7 @@ static void connManager_cleanup()
     int shutdown = appShutdown.fetchAndStoreAcquire(1);
     Q_ASSERT(shutdown == 0);
     Q_UNUSED(shutdown);
-    QNetworkConfigurationManagerPrivate *cmp = connManager_ptr.fetchAndStoreAcquire(0);
+    QNetworkConfigurationManagerPrivate *cmp = connManager_ptr.fetchAndStoreAcquire(nullptr);
     if (cmp)
         cmp->cleanup();
 }
diff --git a/src/network/bearer/qnetworkconfigmanager_p.cpp b/src/network/bearer/qnetworkconfigmanager_p.cpp
index 252b88d36a..f0aa452dd3 100644
--- a/src/network/bearer/qnetworkconfigmanager_p.cpp
+++ b/src/network/bearer/qnetworkconfigmanager_p.cpp
@@ -59,7 +59,7 @@
 QT_BEGIN_NAMESPACE
 
 QNetworkConfigurationManagerPrivate::QNetworkConfigurationManagerPrivate()
-    : QObject(), pollTimer(0),
+    : QObject(), pollTimer(nullptr),
       loader(QBearerEngineFactoryInterface_iid, QLatin1String("/bearer")),
       forcedPolling(0), firstUpdate(true)
 {
@@ -367,7 +367,7 @@ void QNetworkConfigurationManagerPrivate::updateConfigurations()
 
         bool envOK  = false;
         const int skipGeneric = qEnvironmentVariableIntValue("QT_EXCLUDE_GENERIC_BEARER", &envOK);
-        QBearerEngine *generic = 0;
+        QBearerEngine *generic = nullptr;
         QFactoryLoader *l = &loader;
         const PluginKeyMap keyMap = l->keyMap();
         const PluginKeyMapConstIterator cend = keyMap.constEnd();
diff --git a/src/network/bearer/qnetworkconfiguration.cpp b/src/network/bearer/qnetworkconfiguration.cpp
index 19bc44e02a..25c4ab711e 100644
--- a/src/network/bearer/qnetworkconfiguration.cpp
+++ b/src/network/bearer/qnetworkconfiguration.cpp
@@ -209,7 +209,7 @@ QT_BEGIN_NAMESPACE
     \sa isValid()
 */
 QNetworkConfiguration::QNetworkConfiguration()
-    : d(0)
+    : d(nullptr)
 {
 }
 
diff --git a/src/network/bearer/qnetworksession.cpp b/src/network/bearer/qnetworksession.cpp
index 1636bcee97..324016d72a 100644
--- a/src/network/bearer/qnetworksession.cpp
+++ b/src/network/bearer/qnetworksession.cpp
@@ -250,7 +250,7 @@ QT_BEGIN_NAMESPACE
     \sa QNetworkConfiguration
 */
 QNetworkSession::QNetworkSession(const QNetworkConfiguration &connectionConfig, QObject *parent)
-    : QObject(parent), d(0)
+    : QObject(parent), d(nullptr)
 {
     qRegisterMetaType<QNetworkSession::State>();
     qRegisterMetaType<QNetworkSession::SessionError>();
diff --git a/src/network/kernel/qauthenticator.cpp b/src/network/kernel/qauthenticator.cpp
index 33a30eb1cd..e9a8e2a9e5 100644
--- a/src/network/kernel/qauthenticator.cpp
+++ b/src/network/kernel/qauthenticator.cpp
@@ -158,7 +158,7 @@ static QByteArray qGssapiContinue(QAuthenticatorPrivate *ctx,
   Constructs an empty authentication object.
 */
 QAuthenticator::QAuthenticator()
-    : d(0)
+    : d(nullptr)
 {
 }
 
@@ -175,7 +175,7 @@ QAuthenticator::~QAuthenticator()
     Constructs a copy of \a other.
 */
 QAuthenticator::QAuthenticator(const QAuthenticator &other)
-    : d(0)
+    : d(nullptr)
 {
     if (other.d)
         *this = other;
@@ -1227,7 +1227,7 @@ QByteArray qEncodeHmacMd5(QByteArray &key, const QByteArray &message)
 static QByteArray qCreatev2Hash(const QAuthenticatorPrivate *ctx,
                                 QNtlmPhase3Block *phase3)
 {
-    Q_ASSERT(phase3 != 0);
+    Q_ASSERT(phase3 != nullptr);
     // since v2 Hash is need for both NTLMv2 and LMv2 it is calculated
     // only once and stored and reused
     if(phase3->v2Hash.size() == 0) {
@@ -1284,7 +1284,7 @@ static QByteArray qEncodeNtlmv2Response(const QAuthenticatorPrivate *ctx,
                                         const QNtlmPhase2Block& ch,
                                         QNtlmPhase3Block *phase3)
 {
-    Q_ASSERT(phase3 != 0);
+    Q_ASSERT(phase3 != nullptr);
     // return value stored in phase3
     qCreatev2Hash(ctx, phase3);
 
@@ -1351,7 +1351,7 @@ static QByteArray qEncodeLmv2Response(const QAuthenticatorPrivate *ctx,
                                       const QNtlmPhase2Block& ch,
                                       QNtlmPhase3Block *phase3)
 {
-    Q_ASSERT(phase3 != 0);
+    Q_ASSERT(phase3 != nullptr);
     // return value stored in phase3
     qCreatev2Hash(ctx, phase3);
 
diff --git a/src/network/kernel/qdnslookup.cpp b/src/network/kernel/qdnslookup.cpp
index 1b66829070..ab1be02b6b 100644
--- a/src/network/kernel/qdnslookup.cpp
+++ b/src/network/kernel/qdnslookup.cpp
@@ -481,7 +481,7 @@ void QDnsLookup::abort()
 {
     Q_D(QDnsLookup);
     if (d->runnable) {
-        d->runnable = 0;
+        d->runnable = nullptr;
         d->reply = QDnsLookupReply();
         d->reply.error = QDnsLookup::OperationCancelledError;
         d->reply.errorString = tr("Operation cancelled");
@@ -992,7 +992,7 @@ void QDnsLookupPrivate::_q_lookupFinished(const QDnsLookupReply &_reply)
         qDebug("DNS reply for %s: %i (%s)", qPrintable(name), _reply.error, qPrintable(_reply.errorString));
 #endif
         reply = _reply;
-        runnable = 0;
+        runnable = nullptr;
         isFinished = true;
         emit q->finished();
     }
diff --git a/src/network/kernel/qdnslookup_unix.cpp b/src/network/kernel/qdnslookup_unix.cpp
index ee7484ab35..12b40fc35d 100644
--- a/src/network/kernel/qdnslookup_unix.cpp
+++ b/src/network/kernel/qdnslookup_unix.cpp
@@ -73,13 +73,13 @@ QT_BEGIN_NAMESPACE
 typedef struct __res_state* res_state;
 #endif
 typedef int (*dn_expand_proto)(const unsigned char *, const unsigned char *, const unsigned char *, char *, int);
-static dn_expand_proto local_dn_expand = 0;
+static dn_expand_proto local_dn_expand = nullptr;
 typedef void (*res_nclose_proto)(res_state);
-static res_nclose_proto local_res_nclose = 0;
+static res_nclose_proto local_res_nclose = nullptr;
 typedef int (*res_ninit_proto)(res_state);
-static res_ninit_proto local_res_ninit = 0;
+static res_ninit_proto local_res_ninit = nullptr;
 typedef int (*res_nquery_proto)(res_state, const char *, int, int, unsigned char *, int);
-static res_nquery_proto local_res_nquery = 0;
+static res_nquery_proto local_res_nquery = nullptr;
 
 // Custom deleter to close resolver state.
 
diff --git a/src/network/kernel/qhostaddress.cpp b/src/network/kernel/qhostaddress.cpp
index b54fb349fb..ed1c23ed6e 100644
--- a/src/network/kernel/qhostaddress.cpp
+++ b/src/network/kernel/qhostaddress.cpp
@@ -144,7 +144,7 @@ static bool parseIp6(const QString &address, QIPAddressUtils::IPv6Address &addr,
     } else {
         scopeId->clear();
     }
-    return QIPAddressUtils::parseIp6(addr, tmp.constBegin(), tmp.constEnd()) == 0;
+    return QIPAddressUtils::parseIp6(addr, tmp.constBegin(), tmp.constEnd()) == nullptr;
 }
 
 bool QHostAddressPrivate::parse(const QString &ipString)
diff --git a/src/network/kernel/qhostinfo.cpp b/src/network/kernel/qhostinfo.cpp
index f9335c3bb9..31671feece 100644
--- a/src/network/kernel/qhostinfo.cpp
+++ b/src/network/kernel/qhostinfo.cpp
@@ -410,7 +410,7 @@ QHostInfo QHostInfoAgent::reverseLookup(const QHostAddress &address)
     // Reverse lookup
     sockaddr_in sa4;
     sockaddr_in6 sa6;
-    sockaddr *sa = 0;
+    sockaddr *sa = nullptr;
     QT_SOCKLEN_T saSize;
     if (address.protocol() == QAbstractSocket::IPv4Protocol) {
         sa = reinterpret_cast<sockaddr *>(&sa4);
@@ -455,7 +455,7 @@ QHostInfo QHostInfoAgent::lookup(const QString &hostName)
         return results;
     }
 
-    addrinfo *res = 0;
+    addrinfo *res = nullptr;
     struct addrinfo hints;
     memset(&hints, 0, sizeof(hints));
     hints.ai_family = PF_UNSPEC;
diff --git a/src/network/kernel/qhostinfo_unix.cpp b/src/network/kernel/qhostinfo_unix.cpp
index 78a05f8407..625fbabf31 100644
--- a/src/network/kernel/qhostinfo_unix.cpp
+++ b/src/network/kernel/qhostinfo_unix.cpp
@@ -80,12 +80,12 @@ enum LibResolvFeature {
 typedef struct __res_state *res_state_ptr;
 
 typedef int (*res_init_proto)(void);
-static res_init_proto local_res_init = 0;
+static res_init_proto local_res_init = nullptr;
 typedef int (*res_ninit_proto)(res_state_ptr);
-static res_ninit_proto local_res_ninit = 0;
+static res_ninit_proto local_res_ninit = nullptr;
 typedef void (*res_nclose_proto)(res_state_ptr);
-static res_nclose_proto local_res_nclose = 0;
-static res_state_ptr local_res = 0;
+static res_nclose_proto local_res_nclose = nullptr;
+static res_state_ptr local_res = nullptr;
 
 #if QT_CONFIG(library) && !defined(Q_OS_QNX)
 namespace {
diff --git a/src/network/kernel/qnetworkinterface.cpp b/src/network/kernel/qnetworkinterface.cpp
index b7a6d9adf9..eed57f8a32 100644
--- a/src/network/kernel/qnetworkinterface.cpp
+++ b/src/network/kernel/qnetworkinterface.cpp
@@ -627,7 +627,7 @@ bool QNetworkAddressEntry::isPermanent() const
     Constructs an empty network interface object.
 */
 QNetworkInterface::QNetworkInterface()
-    : d(0)
+    : d(nullptr)
 {
 }
 
diff --git a/src/network/kernel/qnetworkproxy.cpp b/src/network/kernel/qnetworkproxy.cpp
index a2a89ed94b..90c8b75a86 100644
--- a/src/network/kernel/qnetworkproxy.cpp
+++ b/src/network/kernel/qnetworkproxy.cpp
@@ -254,13 +254,13 @@ class QGlobalNetworkProxy
 {
 public:
     QGlobalNetworkProxy()
-        : applicationLevelProxy(0)
-        , applicationLevelProxyFactory(0)
+        : applicationLevelProxy(nullptr)
+        , applicationLevelProxyFactory(nullptr)
 #if QT_CONFIG(socks5)
-        , socks5SocketEngineHandler(0)
+        , socks5SocketEngineHandler(nullptr)
 #endif
 #if QT_CONFIG(http)
-        , httpSocketEngineHandler(0)
+        , httpSocketEngineHandler(nullptr)
 #endif
 #ifdef QT_USE_SYSTEM_PROXIES
         , useSystemProxies(true)
@@ -313,7 +313,7 @@ public:
             applicationLevelProxy = new QNetworkProxy;
         *applicationLevelProxy = proxy;
         delete applicationLevelProxyFactory;
-        applicationLevelProxyFactory = 0;
+        applicationLevelProxyFactory = nullptr;
         useSystemProxies = false;
     }
 
@@ -501,7 +501,7 @@ template<> void QSharedDataPointer<QNetworkProxyPrivate>::detach()
     \sa setType(), setApplicationProxy()
 */
 QNetworkProxy::QNetworkProxy()
-    : d(0)
+    : d(nullptr)
 {
     // make sure we have QGlobalNetworkProxy singleton created, otherwise
     // you don't have any socket engine handler created when directly setting
diff --git a/src/network/kernel/qurlinfo.cpp b/src/network/kernel/qurlinfo.cpp
index 7ae6822fb4..e6f2e70ff4 100644
--- a/src/network/kernel/qurlinfo.cpp
+++ b/src/network/kernel/qurlinfo.cpp
@@ -126,7 +126,7 @@ public:
 
 QUrlInfo::QUrlInfo()
 {
-    d = 0;
+    d = nullptr;
 }
 
 /*!
@@ -139,7 +139,7 @@ QUrlInfo::QUrlInfo(const QUrlInfo &ui)
         d = new QUrlInfoPrivate;
         *d = *ui.d;
     } else {
-        d = 0;
+        d = nullptr;
     }
 }
 
@@ -443,7 +443,7 @@ QUrlInfo &QUrlInfo::operator=(const QUrlInfo &ui)
         *d = *ui.d;
     } else {
         delete d;
-        d = 0;
+        d = nullptr;
     }
     return *this;
 }
@@ -683,7 +683,7 @@ bool QUrlInfo::equal(const QUrlInfo &i1, const QUrlInfo &i2,
 bool QUrlInfo::operator==(const QUrlInfo &other) const
 {
     if (!d)
-        return other.d == 0;
+        return other.d == nullptr;
     if (!other.d)
         return false;
 
@@ -721,7 +721,7 @@ bool QUrlInfo::operator==(const QUrlInfo &other) const
 */
 bool QUrlInfo::isValid() const
 {
-    return d != 0;
+    return d != nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/network/socket/qabstractsocket.cpp b/src/network/socket/qabstractsocket.cpp
index e48fbea3b6..cbc4114904 100644
--- a/src/network/socket/qabstractsocket.cpp
+++ b/src/network/socket/qabstractsocket.cpp
@@ -564,12 +564,12 @@ QAbstractSocketPrivate::QAbstractSocketPrivate()
       port(0),
       localPort(0),
       peerPort(0),
-      socketEngine(0),
+      socketEngine(nullptr),
       cachedSocketDescriptor(-1),
       readBufferMaxSize(0),
       isBuffered(false),
       hasPendingData(false),
-      connectTimer(0),
+      connectTimer(nullptr),
       hostLookupId(-1),
       socketType(QAbstractSocket::UnknownSocketType),
       state(QAbstractSocket::UnconnectedState),
@@ -603,7 +603,7 @@ void QAbstractSocketPrivate::resetSocketLayer()
         socketEngine->close();
         socketEngine->disconnect();
         delete socketEngine;
-        socketEngine = 0;
+        socketEngine = nullptr;
         cachedSocketDescriptor = -1;
     }
     if (connectTimer)
diff --git a/src/network/socket/qabstractsocketengine.cpp b/src/network/socket/qabstractsocketengine.cpp
index 3fffff6d5a..54c7452c66 100644
--- a/src/network/socket/qabstractsocketengine.cpp
+++ b/src/network/socket/qabstractsocketengine.cpp
@@ -85,7 +85,7 @@ QAbstractSocketEnginePrivate::QAbstractSocketEnginePrivate()
     , peerPort(0)
     , inboundStreamCount(0)
     , outboundStreamCount(0)
-    , receiver(0)
+    , receiver(nullptr)
 {
 }
 
@@ -104,7 +104,7 @@ QAbstractSocketEngine *QAbstractSocketEngine::createSocketEngine(QAbstractSocket
 #ifndef QT_NO_NETWORKPROXY
     // proxy type must have been resolved by now
     if (proxy.type() == QNetworkProxy::DefaultProxy)
-        return 0;
+        return nullptr;
 #endif
 
     QMutexLocker locker(&socketHandlers()->mutex);
@@ -116,7 +116,7 @@ QAbstractSocketEngine *QAbstractSocketEngine::createSocketEngine(QAbstractSocket
 #ifndef QT_NO_NETWORKPROXY
     // only NoProxy can have reached here
     if (proxy.type() != QNetworkProxy::NoProxy)
-        return 0;
+        return nullptr;
 #endif
 
     return new QNativeSocketEngine(parent);
diff --git a/src/network/socket/qhttpsocketengine.cpp b/src/network/socket/qhttpsocketengine.cpp
index c67b273937..76b3053224 100644
--- a/src/network/socket/qhttpsocketengine.cpp
+++ b/src/network/socket/qhttpsocketengine.cpp
@@ -216,7 +216,7 @@ void QHttpSocketEngine::close()
     if (d->socket) {
         d->socket->close();
         delete d->socket;
-        d->socket = 0;
+        d->socket = nullptr;
     }
 }
 
@@ -586,7 +586,7 @@ void QHttpSocketEngine::slotSocketReadNotification()
     }
 
     int statusCode = d->reply->statusCode();
-    QAuthenticatorPrivate *priv = 0;
+    QAuthenticatorPrivate *priv = nullptr;
     if (statusCode == 200) {
         d->state = Connected;
         setLocalAddress(d->socket->localAddress());
@@ -829,8 +829,8 @@ QHttpSocketEnginePrivate::QHttpSocketEnginePrivate()
     , credentialsSent(false)
     , pendingResponseData(0)
 {
-    socket = 0;
-    reply = 0;
+    socket = nullptr;
+    reply = nullptr;
     state = QHttpSocketEngine::None;
 }
 
@@ -843,15 +843,15 @@ QAbstractSocketEngine *QHttpSocketEngineHandler::createSocketEngine(QAbstractSoc
                                                                     QObject *parent)
 {
     if (socketType != QAbstractSocket::TcpSocket)
-        return 0;
+        return nullptr;
 
     // proxy type must have been resolved by now
     if (proxy.type() != QNetworkProxy::HttpProxy)
-        return 0;
+        return nullptr;
 
     // we only accept active sockets
     if (!qobject_cast<QAbstractSocket *>(parent))
-        return 0;
+        return nullptr;
 
     QHttpSocketEngine *engine = new QHttpSocketEngine(parent);
     engine->setProxy(proxy);
@@ -860,7 +860,7 @@ QAbstractSocketEngine *QHttpSocketEngineHandler::createSocketEngine(QAbstractSoc
 
 QAbstractSocketEngine *QHttpSocketEngineHandler::createSocketEngine(qintptr, QObject *)
 {
-    return 0;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/network/socket/qlocalserver.cpp b/src/network/socket/qlocalserver.cpp
index 3e36a7b229..5ca2db70b9 100644
--- a/src/network/socket/qlocalserver.cpp
+++ b/src/network/socket/qlocalserver.cpp
@@ -417,7 +417,7 @@ QLocalSocket *QLocalServer::nextPendingConnection()
 {
     Q_D(QLocalServer);
     if (d->pendingConnections.isEmpty())
-        return 0;
+        return nullptr;
     QLocalSocket *nextSocket = d->pendingConnections.dequeue();
 #ifndef QT_LOCALSOCKET_TCP
     if (d->pendingConnections.size() <= d->maxPendingConnections)
diff --git a/src/network/socket/qlocalserver_unix.cpp b/src/network/socket/qlocalserver_unix.cpp
index 9547ec5b88..88367d680d 100644
--- a/src/network/socket/qlocalserver_unix.cpp
+++ b/src/network/socket/qlocalserver_unix.cpp
@@ -243,7 +243,7 @@ void QLocalServerPrivate::closeServer()
     if (socketNotifier) {
         socketNotifier->setEnabled(false); // Otherwise, closed socket is checked before deleter runs
         socketNotifier->deleteLater();
-        socketNotifier = 0;
+        socketNotifier = nullptr;
     }
 
     if (-1 != listenSocket)
diff --git a/src/network/socket/qlocalsocket.cpp b/src/network/socket/qlocalsocket.cpp
index af7cdb76d2..d35f838af5 100644
--- a/src/network/socket/qlocalsocket.cpp
+++ b/src/network/socket/qlocalsocket.cpp
@@ -372,7 +372,7 @@ QLocalSocket::~QLocalSocket()
     QLocalSocket::close();
 #if !defined(Q_OS_WIN) && !defined(QT_LOCALSOCKET_TCP)
     Q_D(QLocalSocket);
-    d->unixSocket.setParent(0);
+    d->unixSocket.setParent(nullptr);
 #endif
 }
 
diff --git a/src/network/socket/qlocalsocket_unix.cpp b/src/network/socket/qlocalsocket_unix.cpp
index 3a571edc3a..7de9a7d4c7 100644
--- a/src/network/socket/qlocalsocket_unix.cpp
+++ b/src/network/socket/qlocalsocket_unix.cpp
@@ -61,8 +61,8 @@
 QT_BEGIN_NAMESPACE
 
 QLocalSocketPrivate::QLocalSocketPrivate() : QIODevicePrivate(),
-        delayConnect(0),
-        connectTimer(0),
+        delayConnect(nullptr),
+        connectTimer(nullptr),
         connectingSocket(-1),
         state(QLocalSocket::UnconnectedState)
 {
@@ -379,10 +379,10 @@ void QLocalSocketPrivate::cancelDelayedConnect()
     if (delayConnect) {
         delayConnect->setEnabled(false);
         delete delayConnect;
-        delayConnect = 0;
+        delayConnect = nullptr;
         connectTimer->stop();
         delete connectTimer;
-        connectTimer = 0;
+        connectTimer = nullptr;
     }
 }
 
diff --git a/src/network/socket/qnativesocketengine.cpp b/src/network/socket/qnativesocketengine.cpp
index f3ca2afdc8..31628846dc 100644
--- a/src/network/socket/qnativesocketengine.cpp
+++ b/src/network/socket/qnativesocketengine.cpp
@@ -191,9 +191,9 @@ QT_BEGIN_NAMESPACE
 */
 QNativeSocketEnginePrivate::QNativeSocketEnginePrivate() :
     socketDescriptor(-1),
-    readNotifier(0),
-    writeNotifier(0),
-    exceptNotifier(0)
+    readNotifier(nullptr),
+    writeNotifier(nullptr),
+    exceptNotifier(nullptr)
 {
 #if defined(Q_OS_WIN) && !defined(Q_OS_WINRT)
     QSysInfo::machineHostName();        // this initializes ws2_32.dll
@@ -985,15 +985,15 @@ void QNativeSocketEngine::close()
     d->inboundStreamCount = d->outboundStreamCount = 0;
     if (d->readNotifier) {
         qDeleteInEventHandler(d->readNotifier);
-        d->readNotifier = 0;
+        d->readNotifier = nullptr;
     }
     if (d->writeNotifier) {
         qDeleteInEventHandler(d->writeNotifier);
-        d->writeNotifier = 0;
+        d->writeNotifier = nullptr;
     }
     if (d->exceptNotifier) {
         qDeleteInEventHandler(d->exceptNotifier);
-        d->exceptNotifier = 0;
+        d->exceptNotifier = nullptr;
     }
 }
 
diff --git a/src/network/socket/qnativesocketengine_unix.cpp b/src/network/socket/qnativesocketengine_unix.cpp
index 3ca586e247..e5b9fbbdb2 100644
--- a/src/network/socket/qnativesocketengine_unix.cpp
+++ b/src/network/socket/qnativesocketengine_unix.cpp
@@ -628,7 +628,7 @@ bool QNativeSocketEnginePrivate::nativeListen(int backlog)
 
 int QNativeSocketEnginePrivate::nativeAccept()
 {
-    int acceptedDescriptor = qt_safe_accept(socketDescriptor, 0, 0);
+    int acceptedDescriptor = qt_safe_accept(socketDescriptor, nullptr, nullptr);
     if (acceptedDescriptor == -1) {
         switch (errno) {
         case EBADF:
@@ -1002,7 +1002,7 @@ qint64 QNativeSocketEnginePrivate::nativeReceiveDatagram(char *data, qint64 maxS
         struct cmsghdr *cmsgptr;
         QT_WARNING_PUSH
         QT_WARNING_DISABLE_CLANG("-Wsign-compare")
-        for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL;
+        for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != nullptr;
              cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
             QT_WARNING_POP
             if (cmsgptr->cmsg_level == IPPROTO_IPV6 && cmsgptr->cmsg_type == IPV6_PKTINFO
@@ -1166,7 +1166,7 @@ qint64 QNativeSocketEnginePrivate::nativeSendDatagram(const char *data, qint64 l
 #endif
 
     if (msg.msg_controllen == 0)
-        msg.msg_control = 0;
+        msg.msg_control = nullptr;
     ssize_t sentBytes = qt_safe_sendmsg(socketDescriptor, &msg, 0);
 
     if (sentBytes < 0) {
diff --git a/src/network/socket/qsocks5socketengine.cpp b/src/network/socket/qsocks5socketengine.cpp
index 8a030601dc..622d5df131 100644
--- a/src/network/socket/qsocks5socketengine.cpp
+++ b/src/network/socket/qsocks5socketengine.cpp
@@ -365,13 +365,13 @@ QSocks5BindData *QSocks5BindStore::retrieve(qintptr socketDescriptor)
     QMutexLocker lock(&mutex);
     const auto it = store.constFind(socketDescriptor);
     if (it == store.cend())
-        return 0;
+        return nullptr;
     QSocks5BindData *bindData = it.value();
     store.erase(it);
     if (bindData) {
         if (bindData->controlSocket->thread() != QThread::currentThread()) {
             qWarning("Cannot access socks5 bind data from different thread");
-            return 0;
+            return nullptr;
         }
     } else {
         QSOCKS5_DEBUG << "__ERROR__ binddata == 0";
@@ -503,12 +503,12 @@ QSocks5SocketEnginePrivate::QSocks5SocketEnginePrivate()
     , writeNotificationEnabled(false)
     , exceptNotificationEnabled(false)
     , socketDescriptor(-1)
-    , data(0)
-    , connectData(0)
+    , data(nullptr)
+    , connectData(nullptr)
 #ifndef QT_NO_UDPSOCKET
-    , udpData(0)
+    , udpData(nullptr)
 #endif
-    , bindData(0)
+    , bindData(nullptr)
     , readNotificationActivated(false)
     , writeNotificationActivated(false)
     , readNotificationPending(false)
@@ -1038,11 +1038,11 @@ bool QSocks5SocketEngine::initialize(qintptr socketDescriptor, QAbstractSocket::
         d->data = d->connectData;
         d->mode = QSocks5SocketEnginePrivate::ConnectMode;
         d->data->controlSocket = bindData->controlSocket;
-        bindData->controlSocket = 0;
+        bindData->controlSocket = nullptr;
         d->data->controlSocket->setParent(this);
         d->socketProtocol = d->data->controlSocket->localAddress().protocol();
         d->data->authenticator = bindData->authenticator;
-        bindData->authenticator = 0;
+        bindData->authenticator = nullptr;
         d->localPort = bindData->localPort;
         d->localAddress = bindData->localAddress;
         d->peerPort = bindData->peerPort;
@@ -1367,7 +1367,7 @@ bool QSocks5SocketEngine::bind(const QHostAddress &addr, quint16 port)
     QElapsedTimer stopWatch;
     stopWatch.start();
     d->data->controlSocket->connectToHost(d->proxyInfo.hostName(), d->proxyInfo.port());
-    if (!d->waitForConnected(msecs, 0) ||
+    if (!d->waitForConnected(msecs, nullptr) ||
         d->data->controlSocket->state() == QAbstractSocket::UnconnectedState) {
         // waitForConnected sets the error state and closes the socket
         QSOCKS5_Q_DEBUG << "waitForConnected to proxy server" << d->data->controlSocket->errorString();
@@ -1428,13 +1428,13 @@ int QSocks5SocketEngine::accept()
     case QSocks5SocketEnginePrivate::BindSuccess:
         QSOCKS5_Q_DEBUG << "BindSuccess adding" << d->socketDescriptor << "to the bind store";
         d->data->controlSocket->disconnect();
-        d->data->controlSocket->setParent(0);
+        d->data->controlSocket->setParent(nullptr);
         d->bindData->localAddress = d->localAddress;
         d->bindData->localPort = d->localPort;
         sd = d->socketDescriptor;
         socks5BindStore()->add(sd, d->bindData);
-        d->data = 0;
-        d->bindData = 0;
+        d->data = nullptr;
+        d->bindData = nullptr;
         d->socketDescriptor = 0;
         //### do something about this socket layer ... set it closed and an error about why ...
         // reset state and local port/address
@@ -1909,7 +1909,7 @@ QSocks5SocketEngineHandler::createSocketEngine(QAbstractSocket::SocketType socke
     // proxy type must have been resolved by now
     if (proxy.type() != QNetworkProxy::Socks5Proxy) {
         QSOCKS5_DEBUG << "not proxying";
-        return 0;
+        return nullptr;
     }
     QScopedPointer<QSocks5SocketEngine> engine(new QSocks5SocketEngine(parent));
     engine->setProxy(proxy);
@@ -1923,7 +1923,7 @@ QAbstractSocketEngine *QSocks5SocketEngineHandler::createSocketEngine(qintptr so
         QSOCKS5_DEBUG << "bind store contains" << socketDescriptor;
         return new QSocks5SocketEngine(parent);
     }
-    return 0;
+    return nullptr;
 }
 
 QT_END_NAMESPACE
diff --git a/src/network/socket/qtcpserver.cpp b/src/network/socket/qtcpserver.cpp
index 98e58192a2..9916c75e65 100644
--- a/src/network/socket/qtcpserver.cpp
+++ b/src/network/socket/qtcpserver.cpp
@@ -121,7 +121,7 @@ QTcpServerPrivate::QTcpServerPrivate()
  : port(0)
  , socketType(QAbstractSocket::UnknownSocketType)
  , state(QAbstractSocket::UnconnectedState)
- , socketEngine(0)
+ , socketEngine(nullptr)
  , serverSocketError(QAbstractSocket::UnknownSocketError)
  , maxConnections(30)
 {
@@ -389,7 +389,7 @@ void QTcpServer::close()
             // in out of memory situations, the socketEngine
             // will be deleted in ~QTcpServer (it's a child-object of this)
         }
-        d->socketEngine = 0;
+        d->socketEngine = nullptr;
     }
 
     d->state = QAbstractSocket::UnconnectedState;
@@ -561,7 +561,7 @@ QTcpSocket *QTcpServer::nextPendingConnection()
 {
     Q_D(QTcpServer);
     if (d->pendingConnections.isEmpty())
-        return 0;
+        return nullptr;
 
     if (!d->socketEngine) {
         qWarning("QTcpServer::nextPendingConnection() called while not listening");