Program: 87721
Project: 87721
Buggy source:
private void replayCheckpoint() throws Exception {
  final CheckpointDeserializer deserializer=new CheckpointDeserializer(this.vertexID,!this.isCheckpointLocal);
  final Path checkpointPath=this.isCheckpointLocal ? CheckpointUtils.getLocalCheckpointPath() : CheckpointUtils.getDistributedCheckpointPath();
  if (checkpointPath == null) {
    throw new IOException("String_Node_Str" + this.vertexID);
  }
  final FileSystem fileSystem=checkpointPath.getFileSystem();
  int metaDataIndex=0;
  Buffer firstDeserializedFileBuffer=null;
  FileChannel fileChannel=null;
  try {
    while (true) {
      final Path metaDataFile=checkpointPath.suffix(Path.SEPARATOR + CheckpointUtils.METADATA_PREFIX + "String_Node_Str"+ this.vertexID+ "String_Node_Str"+ metaDataIndex);
      while (!fileSystem.exists(metaDataFile)) {
        final Path finalMetaDataFile=checkpointPath.suffix(Path.SEPARATOR + CheckpointUtils.METADATA_PREFIX + "String_Node_Str"+ this.vertexID+ "String_Node_Str");
        if (fileSystem.exists(finalMetaDataFile)) {
          return;
        }
        if (this.isCheckpointComplete) {
          throw new FileNotFoundException("String_Node_Str" + metaDataIndex + "String_Node_Str"+ this.vertexID);
        }
        Thread.sleep(1000);
      }
      fileChannel=getFileChannel(fileSystem,metaDataFile);
      while (true) {
        try {
          deserializer.read(fileChannel);
          final TransferEnvelope transferEnvelope=deserializer.getFullyDeserializedTransferEnvelope();
          if (transferEnvelope != null) {
            final ReplayOutputChannelBroker broker=this.outputBrokerMap.get(transferEnvelope.getSource());
            if (broker == null) {
              throw new IOException("String_Node_Str" + transferEnvelope.getSource());
            }
            final Buffer srcBuffer=transferEnvelope.getBuffer();
            if (srcBuffer != null) {
              if (firstDeserializedFileBuffer == null) {
                firstDeserializedFileBuffer=srcBuffer.duplicate();
              }
              if (transferEnvelope.getSequenceNumber() < broker.getNextEnvelopeToSend()) {
                srcBuffer.recycleBuffer();
                continue;
              }
              final Buffer destBuffer=broker.requestEmptyBufferBlocking(srcBuffer.size());
              srcBuffer.copyToBuffer(destBuffer);
              transferEnvelope.setBuffer(destBuffer);
              srcBuffer.recycleBuffer();
            }
            broker.outputEnvelope(transferEnvelope);
            if (this.restartRequested.get()) {
              return;
            }
          }
        }
 catch (        EOFException eof) {
          fileChannel.close();
          fileChannel=null;
          ++metaDataIndex;
          break;
        }
      }
    }
  }
  finally {
    if (firstDeserializedFileBuffer != null) {
      firstDeserializedFileBuffer.recycleBuffer();
      firstDeserializedFileBuffer=null;
    }
    if (fileChannel != null) {
      fileChannel.close();
      fileChannel=null;
    }
  }
}

Fixed version (ground truth):
private void replayCheckpoint() throws Exception {
  final CheckpointDeserializer deserializer=new CheckpointDeserializer(this.vertexID,!this.isCheckpointLocal);
  final Path checkpointPath=this.isCheckpointLocal ? CheckpointUtils.getLocalCheckpointPath() : CheckpointUtils.getDistributedCheckpointPath();
  if (checkpointPath == null) {
    throw new IOException("String_Node_Str" + this.vertexID);
  }
  final FileSystem fileSystem=checkpointPath.getFileSystem();
  int metaDataIndex=0;
  Buffer firstDeserializedFileBuffer=null;
  FileChannel fileChannel=null;
  try {
    while (true) {
      final Path metaDataFile=checkpointPath.suffix(Path.SEPARATOR + CheckpointUtils.METADATA_PREFIX + "String_Node_Str"+ this.vertexID+ "String_Node_Str"+ metaDataIndex);
      while (!fileSystem.exists(metaDataFile)) {
        final Path finalMetaDataFile=checkpointPath.suffix(Path.SEPARATOR + CheckpointUtils.METADATA_PREFIX + "String_Node_Str"+ this.vertexID+ "String_Node_Str");
        if (fileSystem.exists(finalMetaDataFile)) {
          return;
        }
        if (this.isCheckpointComplete) {
          throw new FileNotFoundException("String_Node_Str" + metaDataIndex + "String_Node_Str"+ this.vertexID);
        }
        Thread.sleep(1000);
      }
      fileChannel=getFileChannel(fileSystem,metaDataFile);
      while (true) {
        try {
          deserializer.read(fileChannel);
          final TransferEnvelope transferEnvelope=deserializer.getFullyDeserializedTransferEnvelope();
          if (transferEnvelope != null) {
            final ReplayOutputChannelBroker broker=this.outputBrokerMap.get(transferEnvelope.getSource());
            if (broker == null) {
              throw new IOException("String_Node_Str" + transferEnvelope.getSource());
            }
            final Buffer srcBuffer=transferEnvelope.getBuffer();
            if (srcBuffer != null) {
              if (firstDeserializedFileBuffer == null) {
                firstDeserializedFileBuffer=srcBuffer.duplicate();
              }
              if (transferEnvelope.getSequenceNumber() < broker.getNextEnvelopeToSend()) {
                srcBuffer.recycleBuffer();
                continue;
              }
              final Buffer destBuffer=broker.requestEmptyBufferBlocking(srcBuffer.size());
              srcBuffer.copyToBuffer(destBuffer);
              transferEnvelope.setBuffer(destBuffer);
              srcBuffer.recycleBuffer();
            }
            broker.outputEnvelope(transferEnvelope);
            if (this.executionObserver.isCanceled()) {
              return;
            }
            if (this.restartRequested.get()) {
              return;
            }
          }
        }
 catch (        EOFException eof) {
          fileChannel.close();
          fileChannel=null;
          ++metaDataIndex;
          break;
        }
      }
    }
  }
  finally {
    if (firstDeserializedFileBuffer != null) {
      firstDeserializedFileBuffer.recycleBuffer();
      firstDeserializedFileBuffer=null;
    }
    if (fileChannel != null) {
      fileChannel.close();
      fileChannel=null;
    }
  }
}