Catch SecurityException during pairing on Android

QBluetoothLocalDevice::pairingConfirmation(bool) requires
BLUETOOTH_PRIVILEGED permission which cannot be obtained by 3rdparty
apps. I believe this used to be different as suggested by

https://android.googlesource.com/platform/frameworks/base/+/b1dc1757071ba46ee653d68f331486e86778b8e4

This patch ensures that the thrown SecurityException is caught and displays
an appropriate warning.

Change-Id: Ib5a0e0fc0c9f3b4f33690493ed74aa4b7cb8864b
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

2 files changed, 16 insertions, 1 deletions

diff --git a/src/bluetooth/android/localdevicebroadcastreceiver.cpp b/src/bluetooth/android/localdevicebroadcastreceiver.cpp
index ae2a926f..c6cb3680 100644
--- a/src/bluetooth/android/localdevicebroadcastreceiver.cpp
+++ b/src/bluetooth/android/localdevicebroadcastreceiver.cpp
@@ -225,8 +225,18 @@ bool LocalDeviceBroadcastReceiver::pairingConfirmation(bool accept)
     if (!pairingDevice.isValid())
         return false;
 
+    // setPairingConfirmation() is likely to throw SecurityException for BLUETOOTH_PRIVILEGED
+    // as this permission is not obtainable for 3rdparties
+    // Note: Normally it would not have been added to Qt API but it used to be BLUETOOTH_ADMIN
+    QAndroidJniEnvironment env;
     bool success = pairingDevice.callMethod<jboolean>("setPairingConfirmation",
                                               "(Z)Z", accept);
+    if (success) {
+        if (env->ExceptionCheck()) {
+            env->ExceptionDescribe();
+            env->ExceptionClear();
+        }
+    }
     pairingDevice = QAndroidJniObject();
     return success;
 }
diff --git a/src/bluetooth/qbluetoothlocaldevice.cpp b/src/bluetooth/qbluetoothlocaldevice.cpp
index 78095beb..173650a0 100644
--- a/src/bluetooth/qbluetoothlocaldevice.cpp
+++ b/src/bluetooth/qbluetoothlocaldevice.cpp
@@ -272,10 +272,15 @@ bool QBluetoothLocalDevice::isValid() const
 /*!
   \fn QBluetoothLocalDevice::pairingConfirmation(bool confirmation)
 
-  To be called after getting a pairingDisplayConfirmation().  The \a confirmation parameter either
+  To be called after getting a pairingDisplayConfirmation(). The \a confirmation parameter either
   accepts the pairing or rejects it.
 
   Accepting a pairing always refers to the last pairing request issued via \l requestPairing().
+
+  \note This function requires BLUETOOTH_PRIVILEGED permission on Android which is generally not
+  obtainable for 3rdparty. Android's default handler for pairing requests will do this on behalf
+  of the user and the application can ignore this call. Nevertheless the proper Android calls are made
+  in case the application does have the required permissions.
 */
 
 /*!