NPE in TimeoutInputStream
* Android version: 10
* Briar version: 1.4.20 (6b20b03)
* Phone model: SPRD ums512_1h10_Natv
Stacktrace:
```
java.lang.NullPointerException: Attempt to invoke virtual method 'int java.io.InputStream.read(byte[], int, int)' on a null object reference
at org.briarproject.bramble.io.TimeoutInputStream.read(TimeoutInputStream.java:52)
at org.briarproject.bramble.util.IoUtils.read(IoUtils.java:95)
at org.briarproject.bramble.connection.Connection.readTag(Connection.java:59)
at org.briarproject.bramble.connection.Connection.recogniseTag(Connection.java:49)
at org.briarproject.bramble.connection.IncomingDuplexSyncConnection.run(IncomingDuplexSyncConnection.java:44)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:919)
```
Edited log:
```
02-16 17:40:19.815 I/BaseActivity: Pausing ConversationActivity
02-16 17:40:19.842 I/BaseActivity: Creating ConnectViaBluetoothActivity
02-16 17:40:19.870 I/BaseActivity: Starting ConnectViaBluetoothActivity
02-16 17:40:19.872 I/BaseActivity: Resuming ConnectViaBluetoothActivity
02-16 17:40:20.349 I/BaseActivity: Stopping ConversationActivity
02-16 17:40:22.536 I/BaseActivity: Pausing ConnectViaBluetoothActivity
02-16 17:40:22.679 I/BaseActivity: Resuming ConnectViaBluetoothActivity
02-16 17:40:22.690 I/BaseActivity: Pausing ConnectViaBluetoothActivity
02-16 17:40:22.781 I/AndroidBluetoothPlugin: Scan mode: Discoverable
02-16 17:40:22.822 I/BluetoothConnectionLimiterImpl: Limiting started
02-16 17:40:22.833 I/BaseActivity: Resuming ConnectViaBluetoothActivity
02-16 17:40:22.873 I/AndroidBluetoothPlugin: Discovery started
02-16 17:40:25.153 I/BaseActivity: Pausing ConnectViaBluetoothActivity
02-16 17:40:25.310 I/BaseActivity: Resuming ConnectViaBluetoothActivity
02-16 17:40:31.235 I/PollerImpl: Polling plugin org.briarproject.bramble.bluetooth
02-16 17:40:31.239 I/ConnectionRegistryImpl: 0 contacts connected or better: org.briarproject.bramble.bluetooth
02-16 17:40:31.239 I/BluetoothConnectionLimiterImpl: Can't open contact connection while limiting
02-16 17:40:32.850 I/AndroidBluetoothPlugin: Cancelling discovery
02-16 17:40:32.853 I/AndroidBluetoothPlugin: Could not connect to any devices
02-16 17:40:37.857 W/ConnectViaBluetoothViewModel: Failed to connect
02-16 17:40:37.858 I/BluetoothConnectionLimiterImpl: Limiting ended
02-16 17:40:37.894 I/BaseActivity: Pausing ConnectViaBluetoothActivity
02-16 17:40:37.935 I/BaseActivity: Starting ConversationActivity
02-16 17:40:37.938 I/BaseActivity: Resuming ConversationActivity
02-16 17:40:38.418 I/BaseActivity: Stopping ConnectViaBluetoothActivity
02-16 17:40:38.422 I/BaseActivity: Destroying ConnectViaBluetoothActivity
02-16 17:40:43.489 I/BaseActivity: Pausing ConversationActivity
02-16 17:40:43.516 I/BaseActivity: Creating ConnectViaBluetoothActivity
02-16 17:40:43.536 I/BaseActivity: Starting ConnectViaBluetoothActivity
02-16 17:40:43.538 I/BaseActivity: Resuming ConnectViaBluetoothActivity
02-16 17:40:44.003 I/BaseActivity: Stopping ConversationActivity
02-16 17:40:44.794 I/BaseActivity: Pausing ConnectViaBluetoothActivity
02-16 17:40:44.824 I/AndroidBluetoothPlugin: Scan mode: Discoverable
02-16 17:40:44.828 I/BluetoothConnectionLimiterImpl: Limiting started
02-16 17:40:44.836 I/BaseActivity: Resuming ConnectViaBluetoothActivity
02-16 17:40:44.879 I/AndroidBluetoothPlugin: Discovery started
02-16 17:40:47.692 I/AndroidBluetoothPlugin: Discovered AC:[scrubbed]:72
02-16 17:40:50.144 I/AndroidBluetoothPlugin: Discovered 30:[scrubbed]:50
02-16 17:40:51.531 I/AndroidBluetoothPlugin: Discovered AC:[scrubbed]:72
02-16 17:40:52.154 I/AndroidBluetoothPlugin: Discovered AC:[scrubbed]:72
02-16 17:40:52.890 I/AndroidBluetoothPlugin: Discovered CC:[scrubbed]:85
02-16 17:40:53.437 I/AndroidBluetoothPlugin: Discovered CC:[scrubbed]:85
02-16 17:40:54.092 I/AndroidBluetoothPlugin: Discovered AC:[scrubbed]:72
02-16 17:40:54.844 I/AndroidBluetoothPlugin: Cancelling discovery
02-16 17:40:54.848 I/AndroidBluetoothPlugin: Connecting to 30:[scrubbed]:50
02-16 17:40:54.850 I/BluetoothConnectionLimiterImpl: Connection opened, 1 open
02-16 17:40:54.850 I/ConnectViaBluetoothViewModel: Could connect, handling connection
02-16 17:40:54.850 I/BluetoothConnectionLimiterImpl: Limiting ended
02-16 17:40:54.867 I/DuplexOutgoingSession: Generated ack: false
02-16 17:40:54.878 I/DuplexOutgoingSession: Generated batch: false
02-16 17:40:54.880 I/DuplexOutgoingSession: Generated offer: false
02-16 17:40:54.881 I/DuplexOutgoingSession: Generated request: false
02-16 17:40:54.882 I/BaseActivity: Pausing ConnectViaBluetoothActivity
02-16 17:40:54.925 I/BaseActivity: Starting ConversationActivity
02-16 17:40:54.929 I/BaseActivity: Resuming ConversationActivity
02-16 17:40:55.410 I/BaseActivity: Stopping ConnectViaBluetoothActivity
02-16 17:40:55.413 I/BaseActivity: Destroying ConnectViaBluetoothActivity
02-16 17:41:01.986 I/AbstractBluetoothPlugin: Connection received
02-16 17:41:01.986 I/BluetoothConnectionLimiterImpl: Connection opened, 2 open
```
As far as I can tell, this device is the head unit in a car.
The log shows an outgoing Bluetooth connection being made, then an incoming connection being received. Perhaps the Bluetooth stack doesn't support multiple connections (or doesn't support incoming and outgoing connections with the same device). In any case, BluetoothSocket#getInputStream() returns null for the second connection. We should check this (and also for the output stream) and throw an IOException rather than crashing.
issue