src/bluetooth/qbluetoothdevicediscoveryagent_android.cpp

@@ -258,6 +258,7 @@ void QBluetoothDeviceDiscoveryAgentPrivate::startLowEnergyScan()
             env->ExceptionClear();
             m_active = NoScanActive;
             emit q->finished();
+            return;
         }
 
         leScanner.setField<jlong>("qtObject", reinterpret_cast<long>(receiver));
@@ -268,6 +269,7 @@ void QBluetoothDeviceDiscoveryAgentPrivate::startLowEnergyScan()
         qCWarning(QT_BT_ANDROID) << "Cannot start BTLE device scanner";
         m_active = NoScanActive;
         emit q->finished();
+        return;
     }
 
     if (!leScanTimeout) {

src/bluetooth/qbluetoothdevicediscoveryagent_bluez.cpp

@@ -92,12 +92,19 @@ QBluetoothDeviceDiscoveryAgentPrivate::~QBluetoothDeviceDiscoveryAgentPrivate()
     delete adapterBluez5;
 }
 
+//TODO: Qt6 remove the pendingCancel/pendingStart logic as it is cumbersome.
+//      It is a behavior change across all platforms and was initially done
+//      for Bluez. The behavior should be similar to QBluetoothServiceDiscoveryAgent
+//      PendingCancel creates issues whereby the agent is still shutting down
+//      but isActive() below already returns false. This means the isActive() is
+//      out of sync with the finished() and cancel() signal.
+
 bool QBluetoothDeviceDiscoveryAgentPrivate::isActive() const
 {
     if (pendingStart)
         return true;
     if (pendingCancel)
-        return false;
+        return false; //TODO Qt6: remove pending[Cancel|Start] logic (see comment above)
 
     return (adapter || adapterBluez5);
 }
@@ -195,8 +202,8 @@ void QBluetoothDeviceDiscoveryAgentPrivate::start()
         errorString = discoveryReply.error().message();
         lastError = QBluetoothDeviceDiscoveryAgent::InputOutputError;
         Q_Q(QBluetoothDeviceDiscoveryAgent);
-        emit q->error(lastError);
         qCDebug(QT_BT_BLUEZ) << Q_FUNC_INFO << "ERROR: " << errorString;
+        emit q->error(lastError);
         return;
     }
 }
@@ -415,8 +422,8 @@ void QBluetoothDeviceDiscoveryAgentPrivate::_q_propertyChanged(const QString &na
                 adapter->deleteLater();
                 adapter = 0;
 
-                emit q->canceled();
                 pendingCancel = false;
+                emit q->canceled();
             } else if (pendingStart) {
                 adapter->deleteLater();
                 adapter = 0;
@@ -492,8 +499,8 @@ void QBluetoothDeviceDiscoveryAgentPrivate::_q_discoveryFinished()
     adapterBluez5 = 0;
 
     if (pendingCancel && !pendingStart) {
-        emit q->canceled();
         pendingCancel = false;
+        emit q->canceled();
     } else if (pendingStart) {
         pendingStart = false;
         pendingCancel = false;

src/bluetooth/qbluetoothservicediscoveryagent.cpp

@@ -143,9 +143,9 @@ QT_BEGIN_NAMESPACE
     local default Bluetooth adapter.
 */
 QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent(QObject *parent)
-: QObject(parent), d_ptr(new QBluetoothServiceDiscoveryAgentPrivate(QBluetoothAddress()))
+  : QObject(parent),
+    d_ptr(new QBluetoothServiceDiscoveryAgentPrivate(this, QBluetoothAddress()))
 {
-     d_ptr->q_ptr = this;
 }
 
 /*!
@@ -161,9 +161,9 @@ QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent(QObject *parent
     \sa error()
 */
 QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent(const QBluetoothAddress &deviceAdapter, QObject *parent)
-: QObject(parent), d_ptr(new QBluetoothServiceDiscoveryAgentPrivate(deviceAdapter))
+  : QObject(parent),
+    d_ptr(new QBluetoothServiceDiscoveryAgentPrivate(this, deviceAdapter))
 {
-    d_ptr->q_ptr = this;
     if (!deviceAdapter.isNull()) {
         const QList<QBluetoothHostInfo> localDevices = QBluetoothLocalDevice::allDevices();
         foreach (const QBluetoothHostInfo &hostInfo, localDevices) {

src/bluetooth/qbluetoothservicediscoveryagent_android.cpp

@@ -48,11 +48,13 @@ QT_BEGIN_NAMESPACE
 Q_DECLARE_LOGGING_CATEGORY(QT_BT_ANDROID)
 
 QBluetoothServiceDiscoveryAgentPrivate::QBluetoothServiceDiscoveryAgentPrivate(
-        const QBluetoothAddress &/*deviceAdapter*/)
+        QBluetoothServiceDiscoveryAgent *qp, const QBluetoothAddress &/*deviceAdapter*/)
     : error(QBluetoothServiceDiscoveryAgent::NoError),
       state(Inactive), deviceDiscoveryAgent(0),
       mode(QBluetoothServiceDiscoveryAgent::MinimalDiscovery),
-      singleDevice(false), receiver(0), localDeviceReceiver(0)
+      singleDevice(false), receiver(0), localDeviceReceiver(0),
+      q_ptr(qp)
+
 {
     QList<QBluetoothHostInfo> devices = QBluetoothLocalDevice::allDevices();
     Q_ASSERT(devices.count() <= 1); //Android only supports one device at the moment

src/bluetooth/qbluetoothservicediscoveryagent_bluez.cpp

@@ -62,10 +62,12 @@ static inline void convertAddress(quint64 from, quint8 (&to)[6])
     to[5] = (from >> 40) & 0xff;
 }
 
-QBluetoothServiceDiscoveryAgentPrivate::QBluetoothServiceDiscoveryAgentPrivate(const QBluetoothAddress &deviceAdapter)
+QBluetoothServiceDiscoveryAgentPrivate::QBluetoothServiceDiscoveryAgentPrivate(
+    QBluetoothServiceDiscoveryAgent *qp, const QBluetoothAddress &deviceAdapter)
 :   error(QBluetoothServiceDiscoveryAgent::NoError), m_deviceAdapterAddress(deviceAdapter), state(Inactive), deviceDiscoveryAgent(0),
     mode(QBluetoothServiceDiscoveryAgent::MinimalDiscovery), singleDevice(false),
-    manager(0), managerBluez5(0), adapter(0), device(0), sdpScannerProcess(0)
+    manager(0), managerBluez5(0), adapter(0), device(0), sdpScannerProcess(0),
+    q_ptr(qp)
 {
     if (isBluez5()) {
         managerBluez5 = new OrgFreedesktopDBusObjectManagerInterface(

src/bluetooth/qbluetoothservicediscoveryagent_osx.mm

@@ -62,7 +62,8 @@ public:
         ServiceDiscovery,
     };
 
-    QBluetoothServiceDiscoveryAgentPrivate(const QBluetoothAddress &localAddress);
+    QBluetoothServiceDiscoveryAgentPrivate(QBluetoothServiceDiscoveryAgent *qp,
+                                           const QBluetoothAddress &localAddress);
 
     void startDeviceDiscovery();
     void stopDeviceDiscovery();
@@ -110,8 +111,9 @@ private:
     OSXBluetooth::ObjCScopedPointer<ObjCServiceInquiry> serviceInquiry;
 };
 
-QBluetoothServiceDiscoveryAgentPrivate::QBluetoothServiceDiscoveryAgentPrivate(const QBluetoothAddress &localAddress) :
-    q_ptr(0),
+QBluetoothServiceDiscoveryAgentPrivate::QBluetoothServiceDiscoveryAgentPrivate(
+    QBluetoothServiceDiscoveryAgent *qp, const QBluetoothAddress &localAddress) :
+    q_ptr(qp),
     error(QBluetoothServiceDiscoveryAgent::NoError),
     singleDevice(false),
     localAdapterAddress(localAddress),
@@ -423,15 +425,15 @@ void QBluetoothServiceDiscoveryAgentPrivate::serviceDiscoveryFinished()
 }
 
 QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent(QObject *parent)
-: QObject(parent), d_ptr(new QBluetoothServiceDiscoveryAgentPrivate(QBluetoothAddress()))
+: QObject(parent),
+  d_ptr(new QBluetoothServiceDiscoveryAgentPrivate(this, QBluetoothAddress()))
 {
-    d_ptr->q_ptr = this;
 }
 
 QBluetoothServiceDiscoveryAgent::QBluetoothServiceDiscoveryAgent(const QBluetoothAddress &deviceAdapter, QObject *parent)
-: QObject(parent), d_ptr(new QBluetoothServiceDiscoveryAgentPrivate(deviceAdapter))
+: QObject(parent),
+  d_ptr(new QBluetoothServiceDiscoveryAgentPrivate(this, deviceAdapter))
 {
-    d_ptr->q_ptr = this;
     if (!deviceAdapter.isNull()) {
         const QList<QBluetoothHostInfo> localDevices = QBluetoothLocalDevice::allDevices();
         foreach (const QBluetoothHostInfo &hostInfo, localDevices) {

src/bluetooth/qbluetoothservicediscoveryagent_p.cpp

@@ -39,10 +39,14 @@
 
 QT_BEGIN_NAMESPACE
 
-QBluetoothServiceDiscoveryAgentPrivate::QBluetoothServiceDiscoveryAgentPrivate(const QBluetoothAddress &deviceAdapter)
-    :  error(QBluetoothServiceDiscoveryAgent::NoError), state(Inactive),
-       deviceDiscoveryAgent(0), mode(QBluetoothServiceDiscoveryAgent::MinimalDiscovery),
-       singleDevice(false)
+QBluetoothServiceDiscoveryAgentPrivate::QBluetoothServiceDiscoveryAgentPrivate(
+    QBluetoothServiceDiscoveryAgent *qp, const QBluetoothAddress &deviceAdapter)
+    : error(QBluetoothServiceDiscoveryAgent::NoError),
+      state(Inactive),
+      deviceDiscoveryAgent(0),
+      mode(QBluetoothServiceDiscoveryAgent::MinimalDiscovery),
+      singleDevice(false),
+      q_ptr(qp)
 {
 #ifndef QT_IOS_BLUETOOTH
     printDummyWarning();

src/bluetooth/qbluetoothservicediscoveryagent_p.h

@@ -87,7 +87,8 @@ public:
         ServiceDiscovery,
     };
 
-    QBluetoothServiceDiscoveryAgentPrivate(const QBluetoothAddress &deviceAdapter);
+    QBluetoothServiceDiscoveryAgentPrivate(QBluetoothServiceDiscoveryAgent *qp,
+                                           const QBluetoothAddress &deviceAdapter);
     ~QBluetoothServiceDiscoveryAgentPrivate();
 
     void startDeviceDiscovery();

src/nfc/qnearfieldtagtype1.cpp

@@ -76,7 +76,8 @@ public:
     QNearFieldTagType1Private(QNearFieldTagType1 *q)
     :   q_ptr(q), m_readNdefMessageState(NotReadingNdefMessage),
         m_tlvReader(0),
-        m_writeNdefMessageState(NotWritingNdefMessage)
+        m_writeNdefMessageState(NotWritingNdefMessage),
+        m_tlvWriter(0)
     { }
 
     QNearFieldTagType1 *q_ptr;
@@ -164,11 +165,13 @@ void QNearFieldTagType1Private::progressToNextNdefReadMessageState()
         }
 
         m_readNdefMessageState = NdefReadReadingTlv;
+        delete m_tlvReader;
         m_tlvReader = new QTlvReader(q);
 
         // fall through
     }
     case NdefReadReadingTlv:
+        Q_ASSERT(m_tlvReader);
         while (!m_tlvReader->atEnd()) {
             if (!m_tlvReader->readNext())
                 break;
@@ -240,11 +243,13 @@ void QNearFieldTagType1Private::progressToNextNdefWriteMessageState()
         }
 
         m_writeNdefMessageState = NdefWriteReadingTlv;
+        delete m_tlvReader;
         m_tlvReader = new QTlvReader(q);
 
         // fall through
     }
     case NdefWriteReadingTlv:
+        Q_ASSERT(m_tlvReader);
         while (!m_tlvReader->atEnd()) {
             if (!m_tlvReader->readNext())
                 break;
@@ -264,6 +269,7 @@ void QNearFieldTagType1Private::progressToNextNdefWriteMessageState()
 
         // fall through
     case NdefWriteWritingTlv:
+        delete m_tlvWriter;
         m_tlvWriter = new QTlvWriter(q);
 
         // write old TLVs
@@ -282,6 +288,7 @@ void QNearFieldTagType1Private::progressToNextNdefWriteMessageState()
         // fall through
     case NdefWriteWritingTlvFlush:
         // flush the writer
+        Q_ASSERT(m_tlvWriter);
         if (m_tlvWriter->process(true)) {
             m_nextExpectedRequestId = QNearFieldTarget::RequestId();
             m_writeNdefMessageState = NotWritingNdefMessage;