Merge branch 'replace-assert-statements' into 'master'

Replace assert statements with AssertionErrors

See merge request !877

bramble-android/src/main/java/org/briarproject/bramble/network/AndroidNetworkManager.java

@@ -91,7 +91,7 @@ class AndroidNetworkManager implements NetworkManager, Service {
 	public NetworkStatus getNetworkStatus() {
 		ConnectivityManager cm = (ConnectivityManager)
 				appContext.getSystemService(CONNECTIVITY_SERVICE);
-		assert cm != null;
+		if (cm == null) throw new AssertionError();
 		NetworkInfo net = cm.getActiveNetworkInfo();
 		boolean connected = net != null && net.isConnected();
 		boolean wifi = connected && net.getType() == TYPE_WIFI;

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java

@@ -68,7 +68,7 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 				new PoliteExecutor("AndroidLanTcpPlugin", ioExecutor, 1);
 		ConnectivityManager connectivityManager = (ConnectivityManager)
 				appContext.getSystemService(CONNECTIVITY_SERVICE);
-		assert connectivityManager != null;
+		if (connectivityManager == null) throw new AssertionError();
 		this.connectivityManager = connectivityManager;
 		wifiManager = (WifiManager) appContext.getApplicationContext()
 				.getSystemService(WIFI_SERVICE);

bramble-core/src/main/java/org/briarproject/bramble/sync/SyncRecordReaderImpl.java

@@ -46,7 +46,7 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 	}
 
 	private void readRecord() throws IOException {
-		assert nextRecord == null;
+		if (nextRecord != null) throw new AssertionError();
 		while (true) {
 			nextRecord = reader.readRecord();
 			// Check the protocol version
@@ -62,7 +62,7 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 	}
 
 	private byte getNextRecordType() {
-		assert nextRecord != null;
+		if (nextRecord == null) throw new AssertionError();
 		return nextRecord.getRecordType();
 	}
 
@@ -100,7 +100,7 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 	}
 
 	private List<MessageId> readMessageIds() throws IOException {
-		assert nextRecord != null;
+		if (nextRecord == null) throw new AssertionError();
 		byte[] payload = nextRecord.getPayload();
 		if (payload.length == 0) throw new FormatException();
 		if (payload.length % UniqueId.LENGTH != 0) throw new FormatException();
@@ -122,7 +122,7 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 	@Override
 	public Message readMessage() throws IOException {
 		if (!hasMessage()) throw new FormatException();
-		assert nextRecord != null;
+		if (nextRecord == null) throw new AssertionError();
 		byte[] payload = nextRecord.getPayload();
 		if (payload.length < MESSAGE_HEADER_LENGTH) throw new FormatException();
 		// Validate timestamp