output: #fixed code
                                  @Test
      public void testReleaseConnectionWithTimeLimits() throws Exception {
  
          final PoolingHttpClientConnectionManager mgr = new PoolingHttpClientConnectionManager();
          mgr.setMaxTotal(1);
  
          final HttpHost target = getServerHttp();
          final HttpRoute route = new HttpRoute(target, null, false);
          final int      rsplen = 8;
          final String      uri = "/random/" + rsplen;
  
          final HttpRequest request = new BasicHttpRequest("GET", uri, HttpVersion.HTTP_1_1);
          final HttpContext context = new BasicHttpContext();
  
          HttpClientConnection conn = getConnection(mgr, route);
          mgr.connect(conn, route, 0, context);
          mgr.routeComplete(conn, route, context);
  
          context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
          context.setAttribute(ExecutionContext.HTTP_TARGET_HOST, target);
  
          final HttpProcessor httpProcessor = new ImmutableHttpProcessor(
                  new HttpRequestInterceptor[] { new RequestContent(), new RequestConnControl() });
  
          final HttpRequestExecutor exec = new HttpRequestExecutor();
          exec.preProcess(request, httpProcessor, context);
          HttpResponse response = exec.execute(request, conn, context);
  
          Assert.assertEquals("wrong status in first response",
                       HttpStatus.SC_OK,
                       response.getStatusLine().getStatusCode());
          byte[] data = EntityUtils.toByteArray(response.getEntity());
          Assert.assertEquals("wrong length of first response entity",
                       rsplen, data.length);
          // ignore data, but it must be read
  
          // check that there is no auto-release by default
          try {
              // this should fail quickly, connection has not been released
              getConnection(mgr, route, 10L, TimeUnit.MILLISECONDS);
              Assert.fail("ConnectionPoolTimeoutException should have been thrown");
          } catch (final ConnectionPoolTimeoutException e) {
              // expected
          }
  
          conn.close();
          mgr.releaseConnection(conn, null, 100, TimeUnit.MILLISECONDS);
          conn = getConnection(mgr, route);
          Assert.assertFalse("connection should have been closed", conn.isOpen());
  
          // repeat the communication, no need to prepare the request again
          mgr.connect(conn, route, 0, context);
          mgr.routeComplete(conn, route, context);
  
          context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
          response = exec.execute(request, conn, context);
  
          Assert.assertEquals("wrong status in second response",
                       HttpStatus.SC_OK,
                       response.getStatusLine().getStatusCode());
          data = EntityUtils.toByteArray(response.getEntity());
          Assert.assertEquals("wrong length of second response entity",
                       rsplen, data.length);
          // ignore data, but it must be read
  
          mgr.releaseConnection(conn, null, 100, TimeUnit.MILLISECONDS);
          conn = getConnection(mgr, route);
          Assert.assertTrue("connection should have been open", conn.isOpen());
  
          // repeat the communication, no need to prepare the request again
          context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
          response = exec.execute(request, conn, context);
  
          Assert.assertEquals("wrong status in third response",
                       HttpStatus.SC_OK,
                       response.getStatusLine().getStatusCode());
          data = EntityUtils.toByteArray(response.getEntity());
          Assert.assertEquals("wrong length of third response entity",
                       rsplen, data.length);
          // ignore data, but it must be read
  
          mgr.releaseConnection(conn, null, 100, TimeUnit.MILLISECONDS);
          Thread.sleep(150);
          conn = getConnection(mgr, route);
          Assert.assertTrue("connection should have been closed", !conn.isOpen());
  
          // repeat the communication, no need to prepare the request again
          mgr.connect(conn, route, 0, context);
          mgr.routeComplete(conn, route, context);
  
          context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
          response = exec.execute(request, conn, context);
  
          Assert.assertEquals("wrong status in third response",
                       HttpStatus.SC_OK,
                       response.getStatusLine().getStatusCode());
          data = EntityUtils.toByteArray(response.getEntity());
          Assert.assertEquals("wrong length of fourth response entity",
                       rsplen, data.length);
          // ignore data, but it must be read
  
          mgr.shutdown();
      }
input: #vulnerable code 
                                  @Test
      public void testReleaseConnectionWithTimeLimits() throws Exception {
  
          final PoolingHttpClientConnectionManager mgr = new PoolingHttpClientConnectionManager();
          mgr.setMaxTotal(1);
  
          final HttpHost target = getServerHttp();
          final HttpRoute route = new HttpRoute(target, null, false);
          final int      rsplen = 8;
          final String      uri = "/random/" + rsplen;
  
          final HttpRequest request = new BasicHttpRequest("GET", uri, HttpVersion.HTTP_1_1);
          final HttpContext context = new BasicHttpContext();
  
          HttpClientConnection conn = getConnection(mgr, route);
          mgr.connect(conn, route.getTargetHost(), route.getLocalSocketAddress(), 0, context);
  
          context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
          context.setAttribute(ExecutionContext.HTTP_TARGET_HOST, target);
  
          final HttpProcessor httpProcessor = new ImmutableHttpProcessor(
                  new HttpRequestInterceptor[] { new RequestContent(), new RequestConnControl() });
  
          final HttpRequestExecutor exec = new HttpRequestExecutor();
          exec.preProcess(request, httpProcessor, context);
          HttpResponse response = exec.execute(request, conn, context);
  
          Assert.assertEquals("wrong status in first response",
                       HttpStatus.SC_OK,
                       response.getStatusLine().getStatusCode());
          byte[] data = EntityUtils.toByteArray(response.getEntity());
          Assert.assertEquals("wrong length of first response entity",
                       rsplen, data.length);
          // ignore data, but it must be read
  
          // check that there is no auto-release by default
          try {
              // this should fail quickly, connection has not been released
              getConnection(mgr, route, 10L, TimeUnit.MILLISECONDS);
              Assert.fail("ConnectionPoolTimeoutException should have been thrown");
          } catch (final ConnectionPoolTimeoutException e) {
              // expected
          }
  
          conn.close();
          mgr.releaseConnection(conn, null, 100, TimeUnit.MILLISECONDS);
          conn = getConnection(mgr, route);
          Assert.assertFalse("connection should have been closed", conn.isOpen());
  
          // repeat the communication, no need to prepare the request again
          mgr.connect(conn, route.getTargetHost(), route.getLocalSocketAddress(), 0, context);
  
          context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
          response = exec.execute(request, conn, context);
  
          Assert.assertEquals("wrong status in second response",
                       HttpStatus.SC_OK,
                       response.getStatusLine().getStatusCode());
          data = EntityUtils.toByteArray(response.getEntity());
          Assert.assertEquals("wrong length of second response entity",
                       rsplen, data.length);
          // ignore data, but it must be read
  
          mgr.releaseConnection(conn, null, 100, TimeUnit.MILLISECONDS);
          conn = getConnection(mgr, route);
          Assert.assertTrue("connection should have been open", conn.isOpen());
  
          // repeat the communication, no need to prepare the request again
          context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
          response = exec.execute(request, conn, context);
  
          Assert.assertEquals("wrong status in third response",
                       HttpStatus.SC_OK,
                       response.getStatusLine().getStatusCode());
          data = EntityUtils.toByteArray(response.getEntity());
          Assert.assertEquals("wrong length of third response entity",
                       rsplen, data.length);
          // ignore data, but it must be read
  
          mgr.releaseConnection(conn, null, 100, TimeUnit.MILLISECONDS);
          Thread.sleep(150);
          conn = getConnection(mgr, route);
          Assert.assertTrue("connection should have been closed", !conn.isOpen());
  
          // repeat the communication, no need to prepare the request again
          mgr.connect(conn, route.getTargetHost(), route.getLocalSocketAddress(), 0, context);
  
          context.setAttribute(ExecutionContext.HTTP_CONNECTION, conn);
          response = exec.execute(request, conn, context);
  
          Assert.assertEquals("wrong status in third response",
                       HttpStatus.SC_OK,
                       response.getStatusLine().getStatusCode());
          data = EntityUtils.toByteArray(response.getEntity());
          Assert.assertEquals("wrong length of fourth response entity",
                       rsplen, data.length);
          // ignore data, but it must be read
  
          mgr.shutdown();
      } 
                              #location 16 
                              #vulnerability type NULL_DEREFERENCE