#vulnerable code 
                                @Test
    public void testAbortAfterSocketConnect() throws Exception {
        final CountDownLatch connectLatch = new CountDownLatch(1);
        final StallingSocketFactory stallingSocketFactory = new StallingSocketFactory(
                connectLatch, WaitPolicy.AFTER_CONNECT, PlainSocketFactory.getSocketFactory());
        final Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
            .register("http", stallingSocketFactory)
            .build();

        final PoolingHttpClientConnectionManager mgr = new PoolingHttpClientConnectionManager(registry);
        mgr.setMaxTotal(1);

        final HttpHost target = getServerHttp();
        final HttpRoute route = new HttpRoute(target, null, false);
        final HttpContext context = new BasicHttpContext();

        final HttpClientConnection conn = getConnection(mgr, route);

        final AtomicReference<Throwable> throwRef = new AtomicReference<Throwable>();
        final Thread abortingThread = new Thread(new Runnable() {
            public void run() {
                try {
                    stallingSocketFactory.waitForState();
                    conn.shutdown();
                    mgr.releaseConnection(conn, null, -1, null);
                    connectLatch.countDown();
                } catch (final Throwable e) {
                    throwRef.set(e);
                }
            }
        });
        abortingThread.start();

        try {
            mgr.connect(conn, route.getTargetHost(), route.getLocalSocketAddress(), 0, context);
            Assert.fail("IOException expected");
        } catch(final IOException expected) {
        }

        abortingThread.join(5000);
        if(throwRef.get() != null) {
            throw new RuntimeException(throwRef.get());
        }

        Assert.assertFalse(conn.isOpen());
        // Give the server a bit of time to accept the connection, but
        // ensure that it can accept it.
        for(int i = 0; i < 10; i++) {
            if(localServer.getAcceptedConnectionCount() == 1) {
                break;
            }
            Thread.sleep(100);
        }
        Assert.assertEquals(1, localServer.getAcceptedConnectionCount());

        // the connection is expected to be released back to the manager
        final HttpClientConnection conn2 = getConnection(mgr, route, 5L, TimeUnit.SECONDS);
        Assert.assertFalse("connection should have been closed", conn2.isOpen());

        mgr.releaseConnection(conn2, null, -1, null);
        mgr.shutdown();
    } 
                            #location 35 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void testAbortAfterSocketConnect() throws Exception {
        final CountDownLatch connectLatch = new CountDownLatch(1);
        final StallingSocketFactory stallingSocketFactory = new StallingSocketFactory(
                connectLatch, WaitPolicy.AFTER_CONNECT, PlainSocketFactory.getSocketFactory());
        final Registry<ConnectionSocketFactory> registry = RegistryBuilder.<ConnectionSocketFactory>create()
            .register("http", stallingSocketFactory)
            .build();

        final PoolingHttpClientConnectionManager mgr = new PoolingHttpClientConnectionManager(registry);
        mgr.setMaxTotal(1);

        final HttpHost target = getServerHttp();
        final HttpRoute route = new HttpRoute(target, null, false);
        final HttpContext context = new BasicHttpContext();

        final HttpClientConnection conn = getConnection(mgr, route);

        final AtomicReference<Throwable> throwRef = new AtomicReference<Throwable>();
        final Thread abortingThread = new Thread(new Runnable() {
            public void run() {
                try {
                    stallingSocketFactory.waitForState();
                    conn.shutdown();
                    mgr.releaseConnection(conn, null, -1, null);
                    connectLatch.countDown();
                } catch (final Throwable e) {
                    throwRef.set(e);
                }
            }
        });
        abortingThread.start();

        try {
            mgr.connect(conn, route, 0, context);
            mgr.routeComplete(conn, route, context);
            Assert.fail("IOException expected");
        } catch(final IOException expected) {
        }

        abortingThread.join(5000);
        if(throwRef.get() != null) {
            throw new RuntimeException(throwRef.get());
        }

        Assert.assertFalse(conn.isOpen());
        // Give the server a bit of time to accept the connection, but
        // ensure that it can accept it.
        for(int i = 0; i < 10; i++) {
            if(localServer.getAcceptedConnectionCount() == 1) {
                break;
            }
            Thread.sleep(100);
        }
        Assert.assertEquals(1, localServer.getAcceptedConnectionCount());

        // the connection is expected to be released back to the manager
        final HttpClientConnection conn2 = getConnection(mgr, route, 5L, TimeUnit.SECONDS);
        Assert.assertFalse("connection should have been closed", conn2.isOpen());

        mgr.releaseConnection(conn2, null, -1, null);
        mgr.shutdown();
    }