Program: 8203
Project: 8203
Buggy source:
/** 
 * Connect to server
 * @param etcdRequest to request with
 * @param connectionState for retries
 * @param < R > Type of response
 * @throws IOException if request could not be sent.
 */
@SuppressWarnings("String_Node_Str") protected <R>void connect(final EtcdRequest<R> etcdRequest,final ConnectionState connectionState) throws IOException {
  URI uri=uris[connectionState.uriIndex];
  URI requestUri=URI.create(etcdRequest.getUrl());
  if (requestUri.getHost() != null && requestUri.getPort() > -1) {
    uri=requestUri;
  }
  final ChannelFuture connectFuture=bootstrap.clone().connect(uri.getHost(),uri.getPort());
  final Channel channel=connectFuture.channel();
  etcdRequest.getPromise().attachNettyPromise((Promise<R>)new DefaultPromise<>(connectFuture.channel().eventLoop()));
  connectFuture.addListener(new GenericFutureListener<ChannelFuture>(){
    @Override public void operationComplete(    final ChannelFuture f) throws Exception {
      if (!f.isSuccess()) {
        if (logger.isDebugEnabled()) {
          logger.debug(String.format("String_Node_Str" + connectionState.uris[connectionState.uriIndex]));
        }
        etcdRequest.getPromise().handleRetry(f.cause());
        return;
      }
      if (etcdRequest.getPromise().getNettyPromise().isCancelled()) {
        f.channel().close();
        etcdRequest.getPromise().getNettyPromise().setFailure(new CancellationException());
        return;
      }
      final Promise listenedToPromise=etcdRequest.getPromise().getNettyPromise();
      listenedToPromise.addListener(new GenericFutureListener<Future<?>>(){
        @Override public void operationComplete(        Future<?> future) throws Exception {
          if (etcdRequest.getPromise().getNettyPromise() == listenedToPromise) {
            f.channel().close();
          }
        }
      }
);
      if (logger.isDebugEnabled()) {
        logger.debug("String_Node_Str" + channel.remoteAddress().toString());
      }
      lastWorkingUriIndex=connectionState.uriIndex;
      modifyPipeLine(etcdRequest,f.channel().pipeline());
      HttpRequest httpRequest=createHttpRequest(etcdRequest.getUrl(),etcdRequest);
      channel.writeAndFlush(httpRequest).addListener(new ChannelFutureListener(){
        @Override public void operationComplete(        ChannelFuture future) throws Exception {
          if (!future.isSuccess()) {
            etcdRequest.getPromise().setException(future.cause());
            f.channel().close();
          }
        }
      }
);
      channel.closeFuture().addListener(new ChannelFutureListener(){
        @Override public void operationComplete(        ChannelFuture future) throws Exception {
          if (logger.isDebugEnabled()) {
            logger.debug("String_Node_Str" + etcdRequest.getMethod().name() + "String_Node_Str"+ etcdRequest.getUri());
          }
        }
      }
);
    }
  }
);
}

Fixed version (ground truth):
/** 
 * Connect to server
 * @param etcdRequest to request with
 * @param connectionState for retries
 * @param < R > Type of response
 * @throws IOException if request could not be sent.
 */
@SuppressWarnings("String_Node_Str") protected <R>void connect(final EtcdRequest<R> etcdRequest,final ConnectionState connectionState) throws IOException {
  URI uri=uris[connectionState.uriIndex];
  URI requestUri=URI.create(etcdRequest.getUrl());
  if (requestUri.getHost() != null && requestUri.getPort() > -1) {
    uri=requestUri;
  }
  final ChannelFuture connectFuture=bootstrap.clone().connect(uri.getHost(),uri.getPort());
  final Channel channel=connectFuture.channel();
  etcdRequest.getPromise().attachNettyPromise((Promise<R>)new DefaultPromise<>(connectFuture.channel().eventLoop()));
  connectFuture.addListener(new GenericFutureListener<ChannelFuture>(){
    @Override public void operationComplete(    final ChannelFuture f) throws Exception {
      if (!f.isSuccess()) {
        if (logger.isDebugEnabled()) {
          logger.debug(String.format("String_Node_Str" + connectionState.uris[connectionState.uriIndex]));
        }
        etcdRequest.getPromise().handleRetry(f.cause());
        return;
      }
      if (etcdRequest.getPromise().getNettyPromise().isCancelled()) {
        f.channel().close();
        etcdRequest.getPromise().getNettyPromise().setFailure(new CancellationException());
        return;
      }
      final Promise listenedToPromise=etcdRequest.getPromise().getNettyPromise();
      listenedToPromise.addListener(new GenericFutureListener<Future<?>>(){
        @Override public void operationComplete(        Future<?> future) throws Exception {
          if (etcdRequest.getPromise().getNettyPromise() == listenedToPromise) {
            f.channel().close();
          }
        }
      }
);
      if (logger.isDebugEnabled()) {
        logger.debug("String_Node_Str" + channel.remoteAddress().toString());
      }
      lastWorkingUriIndex=connectionState.uriIndex;
      modifyPipeLine(etcdRequest,f.channel().pipeline());
      createAndSendHttpRequest(etcdRequest.getUrl(),etcdRequest,channel).addListener(new ChannelFutureListener(){
        @Override public void operationComplete(        ChannelFuture future) throws Exception {
          if (!future.isSuccess()) {
            etcdRequest.getPromise().setException(future.cause());
            f.channel().close();
          }
        }
      }
);
      channel.closeFuture().addListener(new ChannelFutureListener(){
        @Override public void operationComplete(        ChannelFuture future) throws Exception {
          if (logger.isDebugEnabled()) {
            logger.debug("String_Node_Str" + etcdRequest.getMethod().name() + "String_Node_Str"+ etcdRequest.getUri());
          }
        }
      }
);
    }
  }
);
}