Bluez4: Ensure QBluetoothLocalDevice becomes invalid if adapter disappears

The DBus object disappears when the dongle is removed. Once a
QBluetoothLocalDevice instance is invalid it remains invalid.
The patch further ensures that an invalid instance does not
initiate pairing activitiy.

Last but not least this patch fixes a memory leak in case
a DBus error occurs during the adapter initialization.

Task-number: QTBUG-38399
Change-Id: I2e13e393060c77fab5f79d5451dd6fe9a2a6e3bb
Reviewed-by: Aaron McCarthy <mccarthy.aaron@gmail.com>

3 files changed, 62 insertions, 7 deletions

diff --git a/src/bluetooth/qbluetoothlocaldevice.cpp b/src/bluetooth/qbluetoothlocaldevice.cpp
index 14140846..6560e135 100644
--- a/src/bluetooth/qbluetoothlocaldevice.cpp
+++ b/src/bluetooth/qbluetoothlocaldevice.cpp
@@ -125,8 +125,16 @@ QBluetoothLocalDevice::~QBluetoothLocalDevice()
 }
 
 /*!
-    Returns true if the QBluetoothLocalDevice represents an available local Bluetooth device;
+    Returns \c true if the QBluetoothLocalDevice represents an available local Bluetooth device;
     otherwise return false.
+
+    If the local Bluetooth adapter represented by an instance of this class
+    is removed from the system (e.g. removal of the underlying Bluetooth dongle)
+    then this instance will become invalid. An already invalid QBluetoothLocalDevice instance
+    remains invalid even if the same Bluetooth adapter is returned to
+    the system.
+
+    \sa allDevices()
 */
 bool QBluetoothLocalDevice::isValid() const
 {
diff --git a/src/bluetooth/qbluetoothlocaldevice_bluez.cpp b/src/bluetooth/qbluetoothlocaldevice_bluez.cpp
index ac694f34..d2c8ac1d 100644
--- a/src/bluetooth/qbluetoothlocaldevice_bluez.cpp
+++ b/src/bluetooth/qbluetoothlocaldevice_bluez.cpp
@@ -218,7 +218,7 @@ static inline OrgBluezDeviceInterface *getDevice(const QBluetoothAddress &addres
 
 void QBluetoothLocalDevice::requestPairing(const QBluetoothAddress &address, Pairing pairing)
 {
-    if (address.isNull()) {
+    if (!isValid() || address.isNull()) {
         QMetaObject::invokeMethod(this, "error", Qt::QueuedConnection,
                                   Q_ARG(QBluetoothLocalDevice::Error, QBluetoothLocalDevice::PairingError));
         return;
@@ -347,7 +347,8 @@ QBluetoothLocalDevice::Pairing QBluetoothLocalDevice::pairingStatus(const QBluet
 }
 
 QBluetoothLocalDevicePrivate::QBluetoothLocalDevicePrivate(QBluetoothLocalDevice *q, QBluetoothAddress address)
-    : adapter(0), agent(0), localAddress(address), pendingHostModeChange(-1), msgConnection(0), q_ptr(q)
+    : adapter(0), agent(0), manager(0),
+      localAddress(address), pendingHostModeChange(-1), msgConnection(0), q_ptr(q)
 {
     initializeAdapter();
     connectDeviceChanges();
@@ -368,6 +369,7 @@ QBluetoothLocalDevicePrivate::~QBluetoothLocalDevicePrivate()
     delete msgConnection;
     delete adapter;
     delete agent;
+    delete manager;
     qDeleteAll(devices);
 }
 
@@ -376,17 +378,19 @@ void QBluetoothLocalDevicePrivate::initializeAdapter()
     if (adapter)
         return;
 
-    OrgBluezManagerInterface manager(QLatin1String("org.bluez"), QLatin1String("/"), QDBusConnection::systemBus());
+    QScopedPointer<OrgBluezManagerInterface> man(new OrgBluezManagerInterface(
+                            QStringLiteral("org.bluez"), QStringLiteral("/"),
+                            QDBusConnection::systemBus()));
 
     if (localAddress == QBluetoothAddress()) {
-        QDBusPendingReply<QDBusObjectPath> reply = manager.DefaultAdapter();
+        QDBusPendingReply<QDBusObjectPath> reply = man->DefaultAdapter();
         reply.waitForFinished();
         if (reply.isError())
             return;
 
         adapter = new OrgBluezAdapterInterface(QLatin1String("org.bluez"), reply.value().path(), QDBusConnection::systemBus());
     } else {
-        QDBusPendingReply<QList<QDBusObjectPath> > reply = manager.ListAdapters();
+        QDBusPendingReply<QList<QDBusObjectPath> > reply = man->ListAdapters();
         reply.waitForFinished();
         if (reply.isError())
             return;
@@ -396,8 +400,10 @@ void QBluetoothLocalDevicePrivate::initializeAdapter()
 
             QDBusPendingReply<QVariantMap> reply = tmpAdapter->GetProperties();
             reply.waitForFinished();
-            if (reply.isError())
+            if (reply.isError()) {
+                delete tmpAdapter;
                 continue;
+            }
 
             QBluetoothAddress path_address(reply.value().value(QLatin1String("Address")).toString());
 
@@ -410,6 +416,11 @@ void QBluetoothLocalDevicePrivate::initializeAdapter()
         }
     }
 
+    // monitor case when local adapter is removed
+    manager = man.take();
+    connect(manager, SIGNAL(AdapterRemoved(QDBusObjectPath)),
+            this, SLOT(adapterRemoved(QDBusObjectPath)));
+
     currentMode = static_cast<QBluetoothLocalDevice::HostMode>(-1);
     if (adapter) {
         connect(adapter, SIGNAL(PropertyChanged(QString,QDBusVariant)), SLOT(PropertyChanged(QString,QDBusVariant)));
@@ -425,6 +436,39 @@ bool QBluetoothLocalDevicePrivate::isValid() const
     return adapter;
 }
 
+// Bluez 4
+void QBluetoothLocalDevicePrivate::adapterRemoved(const QDBusObjectPath &devicePath)
+{
+    if (!adapter )
+        return;
+
+    if (adapter->path() != devicePath.path())
+        return;
+
+    qCDebug(QT_BT_BLUEZ) << "Adapter" << devicePath.path()
+                         << "was removed. Invalidating object.";
+    // the current adapter was removed
+    delete adapter;
+    adapter = 0;
+    manager->deleteLater();
+    manager = 0;
+
+    // stop all pairing related activities
+    if (agent) {
+        QDBusConnection::systemBus().unregisterObject(agent_path);
+        delete agent;
+        agent = 0;
+    }
+
+    delete msgConnection;
+    msgConnection = 0;
+
+    // stop all connectivity monitoring
+    qDeleteAll(devices);
+    devices.clear();
+    connectedDevicesSet.clear();
+}
+
 void QBluetoothLocalDevicePrivate::RequestConfirmation(const QDBusObjectPath &in0, uint in1)
 {
     Q_UNUSED(in0);
diff --git a/src/bluetooth/qbluetoothlocaldevice_p.h b/src/bluetooth/qbluetoothlocaldevice_p.h
index f00c33bf..66eb366c 100644
--- a/src/bluetooth/qbluetoothlocaldevice_p.h
+++ b/src/bluetooth/qbluetoothlocaldevice_p.h
@@ -56,6 +56,7 @@
 class OrgBluezAdapterInterface;
 class OrgBluezAgentAdaptor;
 class OrgBluezDeviceInterface;
+class OrgBluezManagerInterface;
 
 QT_BEGIN_NAMESPACE
 class QDBusPendingCallWatcher;
@@ -130,6 +131,7 @@ public:
     QSet<QBluetoothAddress> connectedDevicesSet;
     OrgBluezAdapterInterface *adapter;
     OrgBluezAgentAdaptor *agent;
+    OrgBluezManagerInterface *manager;
 
     QList<QBluetoothAddress> connectedDevices() const;
 
@@ -158,6 +160,7 @@ public Q_SLOTS: // METHODS
     void _q_deviceRemoved(const QDBusObjectPath &device);
     void _q_devicePropertyChanged(const QString &property, const QDBusVariant &value);
     bool isValid() const;
+    void adapterRemoved(const QDBusObjectPath &device);
 
 private:
     void createCache();