Check whether File#listFiles() returns null.

The docs say this can happen for a directory if there's an I/O error.

briar-android/src/org/briarproject/android/AppModule.java

@@ -42,14 +42,17 @@ public class AppModule {
 		this.application = application;
 		uiCallback = new UiCallback() {
 
+			@Override
 			public int showChoice(String[] options, String... message) {
 				throw new UnsupportedOperationException();
 			}
 
+			@Override
 			public boolean showConfirmationMessage(String... message) {
 				throw new UnsupportedOperationException();
 			}
 
+			@Override
 			public void showMessage(String... message) {
 				throw new UnsupportedOperationException();
 			}
@@ -75,24 +78,29 @@ public class AppModule {
 
 			private volatile SecretKey key = null;
 
+			@Override
 			public boolean databaseExists() {
 				if (!dir.isDirectory()) return false;
 				File[] files = dir.listFiles();
 				return files != null && files.length > 0;
 			}
 
+			@Override
 			public File getDatabaseDirectory() {
 				return dir;
 			}
 
+			@Override
 			public void setEncryptionKey(SecretKey key) {
 				this.key = key;
 			}
 
+			@Override
 			public SecretKey getEncryptionKey() {
 				return key;
 			}
 
+			@Override
 			public long getMaxSize() {
 				return Long.MAX_VALUE;
 			}

briar-android/src/org/briarproject/plugins/tor/TorPlugin.java

@@ -248,17 +248,17 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			// Unzip the Tor binary to the filesystem
 			in = getTorInputStream();
 			out = new FileOutputStream(torFile);
-			IoUtils.copy(in, out);
+			IoUtils.copyAndClose(in, out);
 			// Make the Tor binary executable
 			if (!torFile.setExecutable(true, true)) throw new IOException();
 			// Unzip the GeoIP database to the filesystem
 			in = getGeoIpInputStream();
 			out = new FileOutputStream(geoIpFile);
-			IoUtils.copy(in, out);
+			IoUtils.copyAndClose(in, out);
 			// Copy the config file to the filesystem
 			in = getConfigInputStream();
 			out = new FileOutputStream(configFile);
-			IoUtils.copy(in, out);
+			IoUtils.copyAndClose(in, out);
 			doneFile.createNewFile();
 		} catch (IOException e) {
 			tryToClose(in);
@@ -306,8 +306,12 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void listFiles(File f) {
-		if (f.isDirectory()) for (File child : f.listFiles()) listFiles(child);
-		else LOG.info(f.getAbsolutePath());
+		if (f.isDirectory()) {
+			File[] children = f.listFiles();
+			if (children != null) for (File child : children) listFiles(child);
+		} else {
+			LOG.info(f.getAbsolutePath());
+		}
 	}
 
 	private byte[] read(File f) throws IOException {
@@ -322,7 +326,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			}
 			return b;
 		} finally {
-			in.close();
+			tryToClose(in);
 		}
 	}
 

briar-core/src/org/briarproject/db/H2Database.java

@@ -35,6 +35,7 @@ class H2Database extends JdbcDatabase {
 				+ ";WRITE_DELAY=0;DB_CLOSE_ON_EXIT=false";
 	}
 
+	@Override
 	public boolean open() throws DbException {
 		boolean reopen = config.databaseExists();
 		if (!reopen) config.getDatabaseDirectory().mkdirs();
@@ -42,6 +43,7 @@ class H2Database extends JdbcDatabase {
 		return reopen;
 	}
 
+	@Override
 	public void close() throws DbException {
 		// H2 will close the database when the last connection closes
 		try {
@@ -51,6 +53,7 @@ class H2Database extends JdbcDatabase {
 		}
 	}
 
+	@Override
 	public long getFreeSpace() throws DbException {
 		File dir = config.getDatabaseDirectory();
 		long maxSize = config.getMaxSize();
@@ -63,7 +66,9 @@ class H2Database extends JdbcDatabase {
 	private long getDiskSpace(File f) {
 		if (f.isDirectory()) {
 			long total = 0;
-			for (File child : f.listFiles()) total += getDiskSpace(child);
+			File[] children = f.listFiles();
+			if (children != null)
+				for (File child : children) total += getDiskSpace(child);
 			return total;
 		} else if (f.isFile()) {
 			return f.length();

briar-core/src/org/briarproject/reporting/DevReporterImpl.java

@@ -35,7 +35,7 @@ class DevReporterImpl implements DevReporter {
 	private final DevConfig devConfig;
 	private final SocketFactory torSocketFactory;
 
-	public DevReporterImpl(CryptoComponent crypto, DevConfig devConfig,
+	DevReporterImpl(CryptoComponent crypto, DevConfig devConfig,
 			SocketFactory torSocketFactory) {
 		this.crypto = crypto;
 		this.devConfig = devConfig;
@@ -90,7 +90,7 @@ class DevReporterImpl implements DevReporter {
 				Socket s = connectToDevelopers();
 				out = s.getOutputStream();
 				in = new FileInputStream(f);
-				IoUtils.copy(in, out);
+				IoUtils.copyAndClose(in, out);
 				f.delete();
 			} catch (IOException e) {
 				LOG.log(WARNING, "Failed to send reports", e);

briar-core/src/org/briarproject/util/IoUtils.java

@@ -20,7 +20,7 @@ public class IoUtils {
 		}
 	}
 
-	public static void copy(InputStream in, OutputStream out)
+	public static void copyAndClose(InputStream in, OutputStream out)
 			throws IOException {
 		byte[] buf = new byte[4096];
 		try {

briar-tests/src/org/briarproject/TestDatabaseConfig.java

@@ -16,24 +16,29 @@ public class TestDatabaseConfig implements DatabaseConfig {
 		this.maxSize = maxSize;
 	}
 
+	@Override
 	public boolean databaseExists() {
 		if (!dir.isDirectory()) return false;
 		File[] files = dir.listFiles();
 		return files != null && files.length > 0;
 	}
 
+	@Override
 	public File getDatabaseDirectory() {
 		return dir;
 	}
 
+	@Override
 	public void setEncryptionKey(SecretKey key) {
 		this.key = key;
 	}
 
+	@Override
 	public SecretKey getEncryptionKey() {
 		return key;
 	}
 
+	@Override
 	public long getMaxSize() {
 		return maxSize;
 	}