Merge #10483: scripted-diff: Use the C++11 keyword nullptr to denote the pointer literal instead of the macro NULL

90d4d89 scripted-diff: Use the C++11 keyword nullptr to denote the pointer literal instead of the macro NULL (practicalswift)

Pull request description:

  Since C++11 the macro `NULL` may be:
  * an integer literal with value zero, or
  * a prvalue of type `std::nullptr_t`

  By using the C++11 keyword `nullptr` we are guaranteed a prvalue of type `std::nullptr_t`.

  For a more thorough discussion, see "A name for the null pointer: nullptr" (Sutter &
  Stroustrup), http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2431.pdf

  With this patch applied there are no `NULL` macro usages left in the repo:

  ```
  $ git grep NULL -- "*.cpp" "*.h" | egrep -v '(/univalue/|/secp256k1/|/leveldb/|_NULL|NULLDUMMY|torcontrol.*NULL|NULL cert)' | wc -l
  0
  ```

  The road towards `nullptr` (C++11) is split into two PRs:
  * `NULL` → `nullptr` is handled in PR #10483 (scripted, this PR)
  * `0` → `nullptr` is handled in PR #10645 (manual)

Tree-SHA512: 3c395d66f2ad724a8e6fed74b93634de8bfc0c0eafac94e64e5194c939499fefd6e68f047de3083ad0b4eff37df9a8a3a76349aa17d55eabbd8e0412f140a297

19 files changed, 48 insertions, 48 deletions

diff --git a/src/qt/addressbookpage.cpp b/src/qt/addressbookpage.cpp
index cebac46b95..f295bd4689 100644
--- a/src/qt/addressbookpage.cpp
+++ b/src/qt/addressbookpage.cpp
@@ -273,7 +273,7 @@ void AddressBookPage::on_exportButton_clicked()
     // CSV is currently the only supported format
     QString filename = GUIUtil::getSaveFileName(this,
         tr("Export Address List"), QString(),
-        tr("Comma separated file (*.csv)"), NULL);
+        tr("Comma separated file (*.csv)"), nullptr);
 
     if (filename.isNull())
         return;
diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index 4a4116c670..b6cfdf8887 100644
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -305,7 +305,7 @@ void BitcoinCore::initialize()
     } catch (const std::exception& e) {
         handleRunawayException(&e);
     } catch (...) {
-        handleRunawayException(NULL);
+        handleRunawayException(nullptr);
     }
 }
 
@@ -322,7 +322,7 @@ void BitcoinCore::shutdown()
     } catch (const std::exception& e) {
         handleRunawayException(&e);
     } catch (...) {
-        handleRunawayException(NULL);
+        handleRunawayException(nullptr);
     }
 }
 
@@ -383,7 +383,7 @@ void BitcoinApplication::createPaymentServer()
 
 void BitcoinApplication::createOptionsModel(bool resetSettings)
 {
-    optionsModel = new OptionsModel(NULL, resetSettings);
+    optionsModel = new OptionsModel(nullptr, resetSettings);
 }
 
 void BitcoinApplication::createWindow(const NetworkStyle *networkStyle)
@@ -608,7 +608,7 @@ int main(int argc, char *argv[])
     // but before showing splash screen.
     if (IsArgSet("-?") || IsArgSet("-h") || IsArgSet("-help") || IsArgSet("-version"))
     {
-        HelpMessageDialog help(NULL, IsArgSet("-version"));
+        HelpMessageDialog help(nullptr, IsArgSet("-version"));
         help.showOrPrint();
         return EXIT_SUCCESS;
     }
@@ -723,7 +723,7 @@ int main(int argc, char *argv[])
         PrintExceptionContinue(&e, "Runaway exception");
         app.handleRunawayException(QString::fromStdString(GetWarnings("gui")));
     } catch (...) {
-        PrintExceptionContinue(NULL, "Runaway exception");
+        PrintExceptionContinue(nullptr, "Runaway exception");
         app.handleRunawayException(QString::fromStdString(GetWarnings("gui")));
     }
     return rv;
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index 429c18cba8..e3970298e6 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -479,7 +479,7 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel)
         connect(_clientModel, SIGNAL(networkActiveChanged(bool)), this, SLOT(setNetworkActive(bool)));
 
         modalOverlay->setKnownBestHeight(_clientModel->getHeaderTipHeight(), QDateTime::fromTime_t(_clientModel->getHeaderTipTime()));
-        setNumBlocks(_clientModel->getNumBlocks(), _clientModel->getLastBlockDate(), _clientModel->getVerificationProgress(NULL), false);
+        setNumBlocks(_clientModel->getNumBlocks(), _clientModel->getLastBlockDate(), _clientModel->getVerificationProgress(nullptr), false);
         connect(_clientModel, SIGNAL(numBlocksChanged(int,QDateTime,double,bool)), this, SLOT(setNumBlocks(int,QDateTime,double,bool)));
 
         // Receive and report messages from client model
@@ -922,7 +922,7 @@ void BitcoinGUI::message(const QString &title, const QString &message, unsigned
         showNormalIfMinimized();
         QMessageBox mBox((QMessageBox::Icon)nMBoxIcon, strTitle, message, buttons, this);
         int r = mBox.exec();
-        if (ret != NULL)
+        if (ret != nullptr)
             *ret = r == QMessageBox::Ok;
     }
     else
diff --git a/src/qt/bitcoingui.h b/src/qt/bitcoingui.h
index 8731caafc7..aa45ea1f0a 100644
--- a/src/qt/bitcoingui.h
+++ b/src/qt/bitcoingui.h
@@ -168,7 +168,7 @@ public Q_SLOTS:
                             @see CClientUIInterface::MessageBoxFlags
        @param[in] ret       pointer to a bool that will be modified to whether Ok was clicked (modal only)
     */
-    void message(const QString &title, const QString &message, unsigned int style, bool *ret = NULL);
+    void message(const QString &title, const QString &message, unsigned int style, bool *ret = nullptr);
 
 #ifdef ENABLE_WALLET
     /** Set the encryption status as shown in the UI.
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index bffa81137b..28ffda9981 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -634,11 +634,11 @@ bool SetStartOnSystemStartup(bool fAutoStart)
 
     if (fAutoStart)
     {
-        CoInitialize(NULL);
+        CoInitialize(nullptr);
 
         // Get a pointer to the IShellLink interface.
-        IShellLink* psl = NULL;
-        HRESULT hres = CoCreateInstance(CLSID_ShellLink, NULL,
+        IShellLink* psl = nullptr;
+        HRESULT hres = CoCreateInstance(CLSID_ShellLink, nullptr,
             CLSCTX_INPROC_SERVER, IID_IShellLink,
             reinterpret_cast<void**>(&psl));
 
@@ -646,7 +646,7 @@ bool SetStartOnSystemStartup(bool fAutoStart)
         {
             // Get the current executable path
             TCHAR pszExePath[MAX_PATH];
-            GetModuleFileName(NULL, pszExePath, sizeof(pszExePath));
+            GetModuleFileName(nullptr, pszExePath, sizeof(pszExePath));
 
             // Start client minimized
             QString strArgs = "-min";
@@ -674,7 +674,7 @@ bool SetStartOnSystemStartup(bool fAutoStart)
 
             // Query IShellLink for the IPersistFile interface for
             // saving the shortcut in persistent storage.
-            IPersistFile* ppf = NULL;
+            IPersistFile* ppf = nullptr;
             hres = psl->QueryInterface(IID_IPersistFile, reinterpret_cast<void**>(&ppf));
             if (SUCCEEDED(hres))
             {
@@ -781,21 +781,21 @@ LSSharedFileListItemRef findStartupItemInList(LSSharedFileListRef list, CFURLRef
 LSSharedFileListItemRef findStartupItemInList(LSSharedFileListRef list, CFURLRef findUrl)
 {
     // loop through the list of startup items and try to find the bitcoin app
-    CFArrayRef listSnapshot = LSSharedFileListCopySnapshot(list, NULL);
+    CFArrayRef listSnapshot = LSSharedFileListCopySnapshot(list, nullptr);
     for(int i = 0; i < CFArrayGetCount(listSnapshot); i++) {
         LSSharedFileListItemRef item = (LSSharedFileListItemRef)CFArrayGetValueAtIndex(listSnapshot, i);
         UInt32 resolutionFlags = kLSSharedFileListNoUserInteraction | kLSSharedFileListDoNotMountVolumes;
-        CFURLRef currentItemURL = NULL;
+        CFURLRef currentItemURL = nullptr;
 
 #if defined(MAC_OS_X_VERSION_MAX_ALLOWED) && MAC_OS_X_VERSION_MAX_ALLOWED >= 10100
     if(&LSSharedFileListItemCopyResolvedURL)
-        currentItemURL = LSSharedFileListItemCopyResolvedURL(item, resolutionFlags, NULL);
+        currentItemURL = LSSharedFileListItemCopyResolvedURL(item, resolutionFlags, nullptr);
 #if defined(MAC_OS_X_VERSION_MIN_REQUIRED) && MAC_OS_X_VERSION_MIN_REQUIRED < 10100
     else
-        LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);
+        LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, nullptr);
 #endif
 #else
-    LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, NULL);
+    LSSharedFileListItemResolve(item, resolutionFlags, &currentItemURL, nullptr);
 #endif
 
         if(currentItemURL && CFEqual(currentItemURL, findUrl)) {
@@ -807,13 +807,13 @@ LSSharedFileListItemRef findStartupItemInList(LSSharedFileListRef list, CFURLRef
             CFRelease(currentItemURL);
         }
     }
-    return NULL;
+    return nullptr;
 }
 
 bool GetStartOnSystemStartup()
 {
     CFURLRef bitcoinAppUrl = CFBundleCopyBundleURL(CFBundleGetMainBundle());
-    LSSharedFileListRef loginItems = LSSharedFileListCreate(NULL, kLSSharedFileListSessionLoginItems, NULL);
+    LSSharedFileListRef loginItems = LSSharedFileListCreate(nullptr, kLSSharedFileListSessionLoginItems, nullptr);
     LSSharedFileListItemRef foundItem = findStartupItemInList(loginItems, bitcoinAppUrl);
     return !!foundItem; // return boolified object
 }
@@ -821,12 +821,12 @@ bool GetStartOnSystemStartup()
 bool SetStartOnSystemStartup(bool fAutoStart)
 {
     CFURLRef bitcoinAppUrl = CFBundleCopyBundleURL(CFBundleGetMainBundle());
-    LSSharedFileListRef loginItems = LSSharedFileListCreate(NULL, kLSSharedFileListSessionLoginItems, NULL);
+    LSSharedFileListRef loginItems = LSSharedFileListCreate(nullptr, kLSSharedFileListSessionLoginItems, nullptr);
     LSSharedFileListItemRef foundItem = findStartupItemInList(loginItems, bitcoinAppUrl);
 
     if(fAutoStart && !foundItem) {
         // add bitcoin app to startup item list
-        LSSharedFileListInsertItemURL(loginItems, kLSSharedFileListItemBeforeFirst, NULL, NULL, bitcoinAppUrl, NULL, NULL);
+        LSSharedFileListInsertItemURL(loginItems, kLSSharedFileListItemBeforeFirst, nullptr, nullptr, bitcoinAppUrl, nullptr, nullptr);
     }
     else if(!fAutoStart && foundItem) {
         // remove item
diff --git a/src/qt/openuridialog.cpp b/src/qt/openuridialog.cpp
index 5a66161346..3ee656d470 100644
--- a/src/qt/openuridialog.cpp
+++ b/src/qt/openuridialog.cpp
@@ -44,7 +44,7 @@ void OpenURIDialog::accept()
 
 void OpenURIDialog::on_selectFileButton_clicked()
 {
-    QString filename = GUIUtil::getOpenFileName(this, tr("Select payment request file to open"), "", "", NULL);
+    QString filename = GUIUtil::getOpenFileName(this, tr("Select payment request file to open"), "", "", nullptr);
     if(filename.isEmpty())
         return;
     QUrl fileUri = QUrl::fromLocalFile(filename);
diff --git a/src/qt/paymentrequestplus.cpp b/src/qt/paymentrequestplus.cpp
index 01ec416613..897762b1a7 100644
--- a/src/qt/paymentrequestplus.cpp
+++ b/src/qt/paymentrequestplus.cpp
@@ -66,7 +66,7 @@ bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) c
 
     // One day we'll support more PKI types, but just
     // x509 for now:
-    const EVP_MD* digestAlgorithm = NULL;
+    const EVP_MD* digestAlgorithm = nullptr;
     if (paymentRequest.pki_type() == "x509+sha256") {
         digestAlgorithm = EVP_sha256();
     }
@@ -104,7 +104,7 @@ bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) c
         }
 #endif
         const unsigned char *data = (const unsigned char *)certChain.certificate(i).data();
-        X509 *cert = d2i_X509(NULL, &data, certChain.certificate(i).size());
+        X509 *cert = d2i_X509(nullptr, &data, certChain.certificate(i).size());
         if (cert)
             certs.push_back(cert);
     }
@@ -129,7 +129,7 @@ bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) c
         return false;
     }
 
-    char *website = NULL;
+    char *website = nullptr;
     bool fResult = true;
     try
     {
@@ -169,7 +169,7 @@ bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) c
 #endif
         EVP_PKEY *pubkey = X509_get_pubkey(signing_cert);
         EVP_MD_CTX_init(ctx);
-        if (!EVP_VerifyInit_ex(ctx, digestAlgorithm, NULL) ||
+        if (!EVP_VerifyInit_ex(ctx, digestAlgorithm, nullptr) ||
             !EVP_VerifyUpdate(ctx, data_to_verify.data(), data_to_verify.size()) ||
             !EVP_VerifyFinal(ctx, (const unsigned char*)paymentRequest.signature().data(), (unsigned int)paymentRequest.signature().size(), pubkey)) {
             throw SSLVerifyError("Bad signature, invalid payment request.");
@@ -179,7 +179,7 @@ bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) c
 #endif
 
         // OpenSSL API for getting human printable strings from certs is baroque.
-        int textlen = X509_NAME_get_text_by_NID(certname, NID_commonName, NULL, 0);
+        int textlen = X509_NAME_get_text_by_NID(certname, NID_commonName, nullptr, 0);
         website = new char[textlen + 1];
         if (X509_NAME_get_text_by_NID(certname, NID_commonName, website, textlen + 1) == textlen && textlen > 0) {
             merchant = website;
diff --git a/src/qt/paymentserver.cpp b/src/qt/paymentserver.cpp
index 132ee32748..c5e2b78c54 100644
--- a/src/qt/paymentserver.cpp
+++ b/src/qt/paymentserver.cpp
@@ -274,7 +274,7 @@ bool PaymentServer::ipcSendCommandLine()
         if (!socket->waitForConnected(BITCOIN_IPC_CONNECT_TIMEOUT))
         {
             delete socket;
-            socket = NULL;
+            socket = nullptr;
             return false;
         }
 
@@ -290,7 +290,7 @@ bool PaymentServer::ipcSendCommandLine()
         socket->disconnectFromServer();
 
         delete socket;
-        socket = NULL;
+        socket = nullptr;
         fResult = true;
     }
 
@@ -364,7 +364,7 @@ void PaymentServer::initNetManager()
 {
     if (!optionsModel)
         return;
-    if (netManager != NULL)
+    if (netManager != nullptr)
         delete netManager;
 
     // netManager is used to fetch paymentrequests given in bitcoin: URIs
diff --git a/src/qt/paymentserver.h b/src/qt/paymentserver.h
index 7c6d4507fe..2fe6e3e7b1 100644
--- a/src/qt/paymentserver.h
+++ b/src/qt/paymentserver.h
@@ -75,12 +75,12 @@ public:
     PaymentServer(QObject* parent, bool startLocalServer = true);
     ~PaymentServer();
 
-    // Load root certificate authorities. Pass NULL (default)
+    // Load root certificate authorities. Pass nullptr (default)
     // to read from the file specified in the -rootcertificates setting,
     // or, if that's not set, to use the system default root certificates.
     // If you pass in a store, you should not X509_STORE_free it: it will be
     // freed either at exit or when another set of CAs are loaded.
-    static void LoadRootCAs(X509_STORE* store = NULL);
+    static void LoadRootCAs(X509_STORE* store = nullptr);
 
     // Return certificate store
     static X509_STORE* getCertStore();
diff --git a/src/qt/receiverequestdialog.cpp b/src/qt/receiverequestdialog.cpp
index 3752fa4b66..4aa6375d8a 100644
--- a/src/qt/receiverequestdialog.cpp
+++ b/src/qt/receiverequestdialog.cpp
@@ -68,7 +68,7 @@ void QRImageWidget::saveImage()
 {
     if(!pixmap())
         return;
-    QString fn = GUIUtil::getSaveFileName(this, tr("Save QR Code"), QString(), tr("PNG Image (*.png)"), NULL);
+    QString fn = GUIUtil::getSaveFileName(this, tr("Save QR Code"), QString(), tr("PNG Image (*.png)"), nullptr);
     if (!fn.isEmpty())
     {
         exportImage().save(fn);
diff --git a/src/qt/recentrequeststablemodel.cpp b/src/qt/recentrequeststablemodel.cpp
index 4e88c8802c..1c4f7aca86 100644
--- a/src/qt/recentrequeststablemodel.cpp
+++ b/src/qt/recentrequeststablemodel.cpp
@@ -123,7 +123,7 @@ void RecentRequestsTableModel::updateAmountColumnTitle()
 /** Gets title for amount column including current display unit if optionsModel reference available. */
 QString RecentRequestsTableModel::getAmountTitle()
 {
-    return (this->walletModel->getOptionsModel() != NULL) ? tr("Requested") + " ("+BitcoinUnits::name(this->walletModel->getOptionsModel()->getDisplayUnit()) + ")" : "";
+    return (this->walletModel->getOptionsModel() != nullptr) ? tr("Requested") + " ("+BitcoinUnits::name(this->walletModel->getOptionsModel()->getDisplayUnit()) + ")" : "";
 }
 
 QModelIndex RecentRequestsTableModel::index(int row, int column, const QModelIndex &parent) const
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index 232068bf45..3590a98efa 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -60,7 +60,7 @@ const struct {
     {"cmd-reply", ":/icons/tx_output"},
     {"cmd-error", ":/icons/tx_output"},
     {"misc", ":/icons/tx_inout"},
-    {NULL, NULL}
+    {nullptr, nullptr}
 };
 
 namespace {
@@ -532,7 +532,7 @@ void RPCConsole::setClientModel(ClientModel *model)
         setNumConnections(model->getNumConnections());
         connect(model, SIGNAL(numConnectionsChanged(int)), this, SLOT(setNumConnections(int)));
 
-        setNumBlocks(model->getNumBlocks(), model->getLastBlockDate(), model->getVerificationProgress(NULL), false);
+        setNumBlocks(model->getNumBlocks(), model->getLastBlockDate(), model->getVerificationProgress(nullptr), false);
         connect(model, SIGNAL(numBlocksChanged(int,QDateTime,double,bool)), this, SLOT(setNumBlocks(int,QDateTime,double,bool)));
 
         updateNetworkState();
@@ -982,7 +982,7 @@ void RPCConsole::peerLayoutChanged()
     if (!clientModel || !clientModel->getPeerTableModel())
         return;
 
-    const CNodeCombinedStats *stats = NULL;
+    const CNodeCombinedStats *stats = nullptr;
     bool fUnselect = false;
     bool fReselect = false;
 
diff --git a/src/qt/rpcconsole.h b/src/qt/rpcconsole.h
index ec531c99c8..da06818f87 100644
--- a/src/qt/rpcconsole.h
+++ b/src/qt/rpcconsole.h
@@ -36,8 +36,8 @@ public:
     explicit RPCConsole(const PlatformStyle *platformStyle, QWidget *parent);
     ~RPCConsole();
 
-    static bool RPCParseCommandLine(std::string &strResult, const std::string &strCommand, bool fExecute, std::string * const pstrFilteredOut = NULL);
-    static bool RPCExecuteCommandLine(std::string &strResult, const std::string &strCommand, std::string * const pstrFilteredOut = NULL) {
+    static bool RPCParseCommandLine(std::string &strResult, const std::string &strCommand, bool fExecute, std::string * const pstrFilteredOut = nullptr);
+    static bool RPCExecuteCommandLine(std::string &strResult, const std::string &strCommand, std::string * const pstrFilteredOut = nullptr) {
         return RPCParseCommandLine(strResult, strCommand, true, pstrFilteredOut);
     }
 
diff --git a/src/qt/test/paymentservertests.cpp b/src/qt/test/paymentservertests.cpp
index b9a8ad6e28..d9fb869821 100644
--- a/src/qt/test/paymentservertests.cpp
+++ b/src/qt/test/paymentservertests.cpp
@@ -25,7 +25,7 @@ X509 *parse_b64der_cert(const char* cert_data)
     std::vector<unsigned char> data = DecodeBase64(cert_data);
     assert(data.size() > 0);
     const unsigned char* dptr = &data[0];
-    X509 *cert = d2i_X509(NULL, &dptr, data.size());
+    X509 *cert = d2i_X509(nullptr, &dptr, data.size());
     assert(cert);
     return cert;
 }
@@ -66,7 +66,7 @@ void PaymentServerTests::paymentServerTests()
 {
     SelectParams(CBaseChainParams::MAIN);
     OptionsModel optionsModel;
-    PaymentServer* server = new PaymentServer(NULL, false);
+    PaymentServer* server = new PaymentServer(nullptr, false);
     X509_STORE* caStore = X509_STORE_new();
     X509_STORE_add_cert(caStore, parse_b64der_cert(caCert1_BASE64));
     PaymentServer::LoadRootCAs(caStore);
diff --git a/src/qt/transactionrecord.cpp b/src/qt/transactionrecord.cpp
index 03fd734e92..2ece0d0f28 100644
--- a/src/qt/transactionrecord.cpp
+++ b/src/qt/transactionrecord.cpp
@@ -167,7 +167,7 @@ void TransactionRecord::updateStatus(const CWalletTx &wtx)
     // Determine transaction status
 
     // Find the block the tx is in
-    CBlockIndex* pindex = NULL;
+    CBlockIndex* pindex = nullptr;
     BlockMap::iterator mi = mapBlockIndex.find(wtx.hashBlock);
     if (mi != mapBlockIndex.end())
         pindex = (*mi).second;
diff --git a/src/qt/transactionview.cpp b/src/qt/transactionview.cpp
index 43d6e8826b..53c38da9db 100644
--- a/src/qt/transactionview.cpp
+++ b/src/qt/transactionview.cpp
@@ -343,7 +343,7 @@ void TransactionView::exportClicked()
     // CSV is currently the only supported format
     QString filename = GUIUtil::getSaveFileName(this,
         tr("Export Transaction History"), QString(),
-        tr("Comma separated file (*.csv)"), NULL);
+        tr("Comma separated file (*.csv)"), nullptr);
 
     if (filename.isNull())
         return;
diff --git a/src/qt/walletmodel.h b/src/qt/walletmodel.h
index 5258dc6699..6be36a57e2 100644
--- a/src/qt/walletmodel.h
+++ b/src/qt/walletmodel.h
@@ -129,7 +129,7 @@ public:
     TransactionTableModel *getTransactionTableModel();
     RecentRequestsTableModel *getRecentRequestsTableModel();
 
-    CAmount getBalance(const CCoinControl *coinControl = NULL) const;
+    CAmount getBalance(const CCoinControl *coinControl = nullptr) const;
     CAmount getUnconfirmedBalance() const;
     CAmount getImmatureBalance() const;
     bool haveWatchOnly() const;
diff --git a/src/qt/walletview.cpp b/src/qt/walletview.cpp
index 4a18c0bd4d..971f5e0e1a 100644
--- a/src/qt/walletview.cpp
+++ b/src/qt/walletview.cpp
@@ -246,7 +246,7 @@ void WalletView::backupWallet()
 {
     QString filename = GUIUtil::getSaveFileName(this,
         tr("Backup Wallet"), QString(),
-        tr("Wallet Data (*.dat)"), NULL);
+        tr("Wallet Data (*.dat)"), nullptr);
 
     if (filename.isEmpty())
         return;
diff --git a/src/qt/winshutdownmonitor.cpp b/src/qt/winshutdownmonitor.cpp
index d6f40c38b8..d78d9a2358 100644
--- a/src/qt/winshutdownmonitor.cpp
+++ b/src/qt/winshutdownmonitor.cpp
@@ -57,7 +57,7 @@ void WinShutdownMonitor::registerShutdownBlockReason(const QString& strReason, c
 {
     typedef BOOL (WINAPI *PSHUTDOWNBRCREATE)(HWND, LPCWSTR);
     PSHUTDOWNBRCREATE shutdownBRCreate = (PSHUTDOWNBRCREATE)GetProcAddress(GetModuleHandleA("User32.dll"), "ShutdownBlockReasonCreate");
-    if (shutdownBRCreate == NULL) {
+    if (shutdownBRCreate == nullptr) {
         qWarning() << "registerShutdownBlockReason: GetProcAddress for ShutdownBlockReasonCreate failed";
         return;
     }