Add explicit and make public headers compile with -Wzero-as-null-pointer-constant

... or equivalent.

QtBase 5.6 headers already compile that way, so let the other
modules follow suit.

Added explicit where it was missing. This is not a source-
incompatible change, because code that breaks by this is
a bug. Let's not have this sitting around in an LTS.

Task-number: QTBUG-45291
Change-Id: I375361699615d0fc874e0b96a84543e233eff5f0
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@theqtcompany.com>

src/bluetooth/qbluetoothdevicediscoveryagent.h

@@ -69,9 +69,9 @@ public:
     };
     Q_ENUM(InquiryType)
 
-    QBluetoothDeviceDiscoveryAgent(QObject *parent = 0);
+    explicit QBluetoothDeviceDiscoveryAgent(QObject *parent = Q_NULLPTR);
     explicit QBluetoothDeviceDiscoveryAgent(const QBluetoothAddress &deviceAdapter,
-                                            QObject *parent = 0);
+                                            QObject *parent = Q_NULLPTR);
     ~QBluetoothDeviceDiscoveryAgent();
 
     // TODO Remove inquiry type in Qt 6 -> not really used anywhere

src/bluetooth/qbluetoothdeviceinfo.h

@@ -225,7 +225,7 @@ public:
     void setRssi(qint16 signal);
 
     void setServiceUuids(const QList<QBluetoothUuid> &uuids, DataCompleteness completeness);
-    QList<QBluetoothUuid> serviceUuids(DataCompleteness *completeness = 0) const;
+    QList<QBluetoothUuid> serviceUuids(DataCompleteness *completeness = Q_NULLPTR) const;
     DataCompleteness serviceUuidsCompleteness() const;
 
     void setCoreConfigurations(QBluetoothDeviceInfo::CoreConfigurations coreConfigs);

src/bluetooth/qbluetoothlocaldevice.h

@@ -73,8 +73,8 @@ public:
     };
     Q_ENUM(Error)
 
-    QBluetoothLocalDevice(QObject *parent = 0);
-    explicit QBluetoothLocalDevice(const QBluetoothAddress &address, QObject *parent = 0);
+    explicit QBluetoothLocalDevice(QObject *parent = Q_NULLPTR);
+    explicit QBluetoothLocalDevice(const QBluetoothAddress &address, QObject *parent = Q_NULLPTR);
     virtual ~QBluetoothLocalDevice();
 
     bool isValid() const;

src/bluetooth/qbluetoothserver.h

@@ -64,7 +64,7 @@ public:
     };
     Q_ENUM(Error)
 
-    QBluetoothServer(QBluetoothServiceInfo::Protocol serverType, QObject *parent = 0);
+    explicit QBluetoothServer(QBluetoothServiceInfo::Protocol serverType, QObject *parent = Q_NULLPTR);
     ~QBluetoothServer();
 
     void close();

src/bluetooth/qbluetoothservicediscoveryagent.h

@@ -74,8 +74,8 @@ public:
     };
     Q_ENUM(DiscoveryMode)
 
-    QBluetoothServiceDiscoveryAgent(QObject *parent = 0);
-    explicit QBluetoothServiceDiscoveryAgent(const QBluetoothAddress &deviceAdapter, QObject *parent = 0);
+    explicit QBluetoothServiceDiscoveryAgent(QObject *parent = Q_NULLPTR);
+    explicit QBluetoothServiceDiscoveryAgent(const QBluetoothAddress &deviceAdapter, QObject *parent = Q_NULLPTR);
     ~QBluetoothServiceDiscoveryAgent();
 
     bool isActive() const;

src/bluetooth/qbluetoothsocket.h

@@ -82,8 +82,8 @@ public:
     };
     Q_ENUM(SocketError)
 
-    explicit QBluetoothSocket(QBluetoothServiceInfo::Protocol socketType, QObject *parent = 0);   // create socket of type socketType
-    QBluetoothSocket(QObject *parent = 0);  // create a blank socket
+    explicit QBluetoothSocket(QBluetoothServiceInfo::Protocol socketType, QObject *parent = Q_NULLPTR);   // create socket of type socketType
+    explicit QBluetoothSocket(QObject *parent = Q_NULLPTR);  // create a blank socket
     virtual ~QBluetoothSocket();
 
     void abort();

src/bluetooth/qbluetoothtransfermanager.h

@@ -52,7 +52,7 @@ class Q_BLUETOOTH_EXPORT QBluetoothTransferManager : public QObject
     Q_OBJECT
 
 public:
-    explicit QBluetoothTransferManager(QObject *parent = 0);
+    explicit QBluetoothTransferManager(QObject *parent = Q_NULLPTR);
     ~QBluetoothTransferManager();
 
     QBluetoothTransferReply *put(const QBluetoothTransferRequest &request, QIODevice *data);

src/bluetooth/qbluetoothtransferreply.h

@@ -82,7 +82,7 @@ Q_SIGNALS:
     void error(QBluetoothTransferReply::TransferError lastError);
 
 protected:
-    explicit QBluetoothTransferReply(QObject *parent = 0);
+    explicit QBluetoothTransferReply(QObject *parent = Q_NULLPTR);
     void setManager(QBluetoothTransferManager *manager);
     void setRequest(const QBluetoothTransferRequest &request);
 

src/bluetooth/qbluetoothuuid.h

@@ -376,8 +376,8 @@ public:
 
     int minimumSize() const;
 
-    quint16 toUInt16(bool *ok = 0) const;
-    quint32 toUInt32(bool *ok = 0) const;
+    quint16 toUInt16(bool *ok = Q_NULLPTR) const;
+    quint32 toUInt32(bool *ok = Q_NULLPTR) const;
     quint128 toUInt128() const;
 
     static QString serviceClassToString(ServiceClassUuid uuid);

src/bluetooth/qlowenergycontroller.h

@@ -74,12 +74,12 @@ public:
     Q_ENUM(RemoteAddressType)
 
     explicit QLowEnergyController(const QBluetoothAddress &remoteDevice,
-                                     QObject *parent = 0); // TODO Qt 6 remove ctor
+                                  QObject *parent = Q_NULLPTR); // TODO Qt 6 remove ctor
     explicit QLowEnergyController(const QBluetoothDeviceInfo &remoteDevice,
-                                     QObject *parent = 0);
+                                  QObject *parent = Q_NULLPTR);
     explicit QLowEnergyController(const QBluetoothAddress &remoteDevice,
                                      const QBluetoothAddress &localDevice,
-                                     QObject *parent = 0); // TODO Qt 6 remove ctor
+                                  QObject *parent = Q_NULLPTR); // TODO Qt 6 remove ctor
     ~QLowEnergyController();
 
     QBluetoothAddress localAddress() const;
@@ -97,8 +97,7 @@ public:
 
     void discoverServices();
     QList<QBluetoothUuid> services() const;
-    QLowEnergyService *createServiceObject(
-            const QBluetoothUuid &service, QObject *parent = 0);
+    QLowEnergyService *createServiceObject(const QBluetoothUuid &service, QObject *parent = Q_NULLPTR);
 
     Error error() const;
     QString errorString() const;

src/bluetooth/qlowenergyservice.h

@@ -127,7 +127,7 @@ private:
     // QLowEnergyController is the factory for this class
     friend class QLowEnergyController;
     QLowEnergyService(QSharedPointer<QLowEnergyServicePrivate> p,
-                      QObject *parent = 0);
+                      QObject *parent = Q_NULLPTR);
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QLowEnergyService::ServiceTypes)

src/nfc/qnearfieldmanager.h

@@ -59,8 +59,8 @@ public:
     Q_ENUM(TargetAccessMode)
     Q_DECLARE_FLAGS(TargetAccessModes, TargetAccessMode)
 
-    explicit QNearFieldManager(QObject *parent = 0);
-    explicit QNearFieldManager(QNearFieldManagerPrivate *backend, QObject *parent = 0);
+    explicit QNearFieldManager(QObject *parent = Q_NULLPTR);
+    explicit QNearFieldManager(QNearFieldManagerPrivate *backend, QObject *parent = Q_NULLPTR);
     ~QNearFieldManager();
 
     bool isAvailable() const;

src/nfc/qnearfieldsharemanager.h

@@ -47,7 +47,7 @@ class Q_NFC_EXPORT QNearFieldShareManager : public QObject
     Q_OBJECT
 
 public:
-    explicit QNearFieldShareManager(QObject *parent = 0);
+    explicit QNearFieldShareManager(QObject *parent = Q_NULLPTR);
     ~QNearFieldShareManager();
 
     enum ShareError {

src/nfc/qnearfieldsharetarget.h

@@ -63,7 +63,7 @@ Q_SIGNALS:
     void shareFinished();
 
 private:
-    explicit QNearFieldShareTarget(QNearFieldShareManager::ShareModes modes, QObject *parent = 0);
+    explicit QNearFieldShareTarget(QNearFieldShareManager::ShareModes modes, QObject *parent = Q_NULLPTR);
 
     QNearFieldShareTargetPrivate *d_ptr;
     Q_DECLARE_PRIVATE(QNearFieldShareTarget)

src/nfc/qnearfieldtarget.h

@@ -110,7 +110,7 @@ public:
         QSharedDataPointer<RequestIdPrivate> d;
     };
 
-    explicit QNearFieldTarget(QObject *parent = 0);
+    explicit QNearFieldTarget(QObject *parent = Q_NULLPTR);
     virtual ~QNearFieldTarget();
 
     virtual QByteArray uid() const = 0;

src/nfc/qqmlndefrecord.h

@@ -63,8 +63,8 @@ public:
     };
     Q_ENUM(TypeNameFormat)
 
-    explicit QQmlNdefRecord(QObject *parent = 0);
-    explicit QQmlNdefRecord(const QNdefRecord &record, QObject *parent = 0);
+    explicit QQmlNdefRecord(QObject *parent = Q_NULLPTR);
+    explicit QQmlNdefRecord(const QNdefRecord &record, QObject *parent = Q_NULLPTR);
     ~QQmlNdefRecord();
 
     QString type() const;