Document the preference of nullptr over NULL or (void*)0

src/qt/macdockiconhandler.mm

@@ -18,7 +18,7 @@
 extern void qt_mac_set_dock_menu(QMenu *);
 #endif
 
-static MacDockIconHandler *s_instance = NULL;
+static MacDockIconHandler *s_instance = nullptr;
 
 bool dockClickHandler(id self,SEL _cmd,...) {
     Q_UNUSED(self)
@@ -34,7 +34,7 @@ void setupDockClickHandler() {
     Class cls = objc_getClass("NSApplication");
     id appInst = objc_msgSend((id)cls, sel_registerName("sharedApplication"));
     
-    if (appInst != NULL) {
+    if (appInst != nullptr) {
         id delegate = objc_msgSend(appInst, sel_registerName("delegate"));
         Class delClass = (Class)objc_msgSend(delegate,  sel_registerName("class"));
         SEL shouldHandle = sel_registerName("applicationShouldHandleReopen:hasVisibleWindows:");
@@ -53,7 +53,7 @@ MacDockIconHandler::MacDockIconHandler() : QObject()
     setupDockClickHandler();
     this->m_dummyWidget = new QWidget();
     this->m_dockMenu = new QMenu(this->m_dummyWidget);
-    this->setMainWindow(NULL);
+    this->setMainWindow(nullptr);
 #if QT_VERSION < 0x050000
     qt_mac_set_dock_menu(this->m_dockMenu);
 #elif QT_VERSION >= 0x050200
@@ -69,7 +69,7 @@ void MacDockIconHandler::setMainWindow(QMainWindow *window) {
 MacDockIconHandler::~MacDockIconHandler()
 {
     delete this->m_dummyWidget;
-    this->setMainWindow(NULL);
+    this->setMainWindow(nullptr);
 }
 
 QMenu *MacDockIconHandler::dockMenu()

src/qt/macnotificationhandler.mm

@@ -75,7 +75,7 @@ bool MacNotificationHandler::hasUserNotificationCenterSupport(void)
 
 MacNotificationHandler *MacNotificationHandler::instance()
 {
-    static MacNotificationHandler *s_instance = NULL;
+    static MacNotificationHandler *s_instance = nullptr;
     if (!s_instance) {
         s_instance = new MacNotificationHandler();
         

src/random.cpp

@@ -242,7 +242,7 @@ void GetOSRand(unsigned char *ent32)
     }
 #elif defined(HAVE_GETENTROPY_RAND) && defined(MAC_OSX)
     // We need a fallback for OSX < 10.12
-    if (&getentropy != NULL) {
+    if (&getentropy != nullptr) {
         if (getentropy(ent32, NUM_OS_RANDOM_BYTES) != 0) {
             RandFailure();
         }