From 6ee57315dd05652935cedcc23f56382b504b3bb6 Mon Sep 17 00:00:00 2001
From: Torsten Grote <t@grobox.de>
Date: Mon, 12 Apr 2021 08:18:54 -0300
Subject: [PATCH] Prevent NPE when onQrCodeDecoded() is called after we stop to
 listen

---
 .../contact/add/nearby/AddNearbyContactViewModel.java       | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactViewModel.java b/briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactViewModel.java
index 0f7c0e5bb..7d69bd954 100644
--- a/briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactViewModel.java
+++ b/briar-android/src/main/java/org/briarproject/briar/android/contact/add/nearby/AddNearbyContactViewModel.java
@@ -74,7 +74,6 @@ import static android.bluetooth.BluetoothAdapter.ACTION_SCAN_MODE_CHANGED;
 import static android.bluetooth.BluetoothAdapter.EXTRA_SCAN_MODE;
 import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE;
 import static android.widget.Toast.LENGTH_LONG;
-import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
@@ -417,15 +416,16 @@ class AddNearbyContactViewModel extends AndroidViewModel
 	@IoExecutor
 	public void onQrCodeDecoded(Result result) {
 		LOG.info("Got result from decoder");
+		KeyAgreementTask currentTask = task;
 		// Ignore results until the KeyAgreementTask is ready
-		if (!gotLocalPayload || gotRemotePayload) return;
+		if (!gotLocalPayload || gotRemotePayload || currentTask == null) return;
 		try {
 			byte[] payloadBytes = result.getText().getBytes(ISO_8859_1);
 			if (LOG.isLoggable(INFO))
 				LOG.info("Remote payload is " + payloadBytes.length + " bytes");
 			Payload remotePayload = payloadParser.parse(payloadBytes);
 			gotRemotePayload = true;
-			requireNonNull(task).connectAndRunProtocol(remotePayload);
+			currentTask.connectAndRunProtocol(remotePayload);
 			state.postValue(new AddContactState.QrCodeScanned());
 		} catch (UnsupportedVersionException e) {
 			resetPayloadFlags();