Program: 56063
Project: 56063
Buggy source:
/** 
 * {@inheritDoc}
 */
@Override public void invoke() throws Exception {
  KeyValuePair<Key,Value> pair=null;
  LOG.info("String_Node_Str" + this.getEnvironment().getTaskName() + "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
  final Iterator<FileInputSplit> splitIterator=getFileInputSplits();
  boolean immutable=config.getMutability() == Config.Mutability.IMMUTABLE;
  while (!this.taskCanceled && splitIterator.hasNext()) {
    final FileInputSplit split=splitIterator.next();
    final long start=split.getStart();
    final long length=split.getLength();
    LOG.debug("String_Node_Str" + split.getPath() + "String_Node_Str"+ this.getEnvironment().getTaskName()+ "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
    FSDataInputStream fdis=null;
    InputSplitOpenThread isot=new InputSplitOpenThread(split);
    isot.start();
    try {
      isot.join();
    }
 catch (    InterruptedException ie) {
      if (isot.getFSDataInputStream() != null) {
        isot.getFSDataInputStream().close();
      }
    }
    if (!this.taskCanceled) {
      try {
        if (!isot.fsDataInputStreamSuccessfullyObtained()) {
          throw isot.getException();
        }
        fdis=isot.getFSDataInputStream();
        format.setInput(new DistributedDataInputStream(fdis),start,length,(1024 * 1024));
        format.open();
        LOG.debug("String_Node_Str" + split.getPath() + "String_Node_Str"+ this.getEnvironment().getTaskName()+ "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
        if (!immutable) {
          pair=format.createPair();
        }
        while (!this.taskCanceled && !format.reachedEnd()) {
          if (immutable) {
            pair=format.createPair();
          }
          boolean valid=format.nextPair(pair);
          if (valid) {
            output.collect(pair.getKey(),pair.getValue());
          }
        }
        LOG.debug("String_Node_Str" + split.getPath() + "String_Node_Str"+ this.getEnvironment().getTaskName()+ "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
      }
 catch (      Exception ex) {
        if (!this.taskCanceled) {
          LOG.error("String_Node_Str" + this.getEnvironment().getTaskName() + "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
          throw ex;
        }
      }
 finally {
        if (format != null) {
          format.closeInput();
          format.close();
        }
        if (fdis != null) {
          fdis.close();
        }
      }
    }
  }
  if (!this.taskCanceled) {
    LOG.info("String_Node_Str" + this.getEnvironment().getTaskName() + "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
  }
 else {
    LOG.warn("String_Node_Str" + this.getEnvironment().getTaskName() + "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
  }
}

Fixed version (ground truth):
/** 
 * {@inheritDoc}
 */
@Override public void invoke() throws Exception {
  KeyValuePair<Key,Value> pair=null;
  LOG.info("String_Node_Str" + this.getEnvironment().getTaskName() + "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
  final Iterator<FileInputSplit> splitIterator=getFileInputSplits();
  boolean immutable=config.getMutability() == Config.Mutability.IMMUTABLE;
  while (!this.taskCanceled && splitIterator.hasNext()) {
    final FileInputSplit split=splitIterator.next();
    final long start=split.getStart();
    final long length=split.getLength();
    LOG.debug("String_Node_Str" + split.getPath() + "String_Node_Str"+ this.getEnvironment().getTaskName()+ "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
    FSDataInputStream fdis=null;
    InputSplitOpenThread isot=new InputSplitOpenThread(split);
    isot.start();
    try {
      isot.join();
    }
 catch (    InterruptedException ie) {
      if (isot.getFSDataInputStream() != null) {
        isot.getFSDataInputStream().close();
      }
    }
    if (!this.taskCanceled) {
      try {
        if (!isot.fsDataInputStreamSuccessfullyObtained()) {
          throw isot.getException();
        }
        fdis=isot.getFSDataInputStream();
        format.setInput(new DistributedDataInputStream(fdis),start,length,(1024 * 1024));
        format.open();
        LOG.debug("String_Node_Str" + split.getPath() + "String_Node_Str"+ this.getEnvironment().getTaskName()+ "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
        if (!immutable) {
          pair=format.createPair();
        }
        while (!this.taskCanceled && !format.reachedEnd()) {
          if (immutable) {
            pair=format.createPair();
          }
          boolean valid=format.nextPair(pair);
          if (valid) {
            output.collect(pair.getKey(),pair.getValue());
          }
        }
        LOG.debug("String_Node_Str" + split.getPath() + "String_Node_Str"+ this.getEnvironment().getTaskName()+ "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
      }
 catch (      Exception ex) {
        if (!this.taskCanceled) {
          LOG.error("String_Node_Str" + this.getEnvironment().getTaskName() + "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
          throw ex;
        }
      }
 finally {
        if (format != null) {
          try {
            format.closeInput();
          }
 catch (          IOException ioe) {
            LOG.error("String_Node_Str");
            throw ioe;
          }
          try {
            format.close();
          }
 catch (          IOException ioe) {
            LOG.error("String_Node_Str");
            throw ioe;
          }
        }
      }
    }
  }
  if (!this.taskCanceled) {
    LOG.info("String_Node_Str" + this.getEnvironment().getTaskName() + "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
  }
 else {
    LOG.warn("String_Node_Str" + this.getEnvironment().getTaskName() + "String_Node_Str"+ (this.getEnvironment().getIndexInSubtaskGroup() + 1)+ "String_Node_Str"+ this.getEnvironment().getCurrentNumberOfSubtasks()+ "String_Node_Str");
  }
}