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>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/bluetooth/qbluetoothtransfermanager.h b/src/bluetooth/qbluetoothtransfermanager.h
index 6d6b0318..d4257fab 100644
--- a/src/bluetooth/qbluetoothtransfermanager.h
+++ b/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);