Program: 113307
Project: 113307
Buggy source:
/** 
 * Finds differences between the two specified trees.
 * @return an iterator to a set of differences between the two trees
 * @see DiffEntry
 */
@Override protected Iterator<DiffEntry> _call() throws IllegalArgumentException {
  checkNotNull(oldRefSpec,"String_Node_Str");
  checkNotNull(newRefSpec,"String_Node_Str");
  final RevTree oldTree=resolveTree(oldRefSpec);
  final RevTree newTree=resolveTree(newRefSpec);
  if (oldTree.equals(newTree)) {
    return Iterators.emptyIterator();
  }
  ObjectDatabase leftSource=resolveSource(oldTree.getId());
  ObjectDatabase rightSource=resolveSource(newTree.getId());
  final DiffTreeVisitor visitor=new DiffTreeVisitor(oldTree,newTree,leftSource,rightSource);
  final BlockingQueue<DiffEntry> queue=new ArrayBlockingQueue<>(100);
  final DiffEntryProducer diffProducer=new DiffEntryProducer(queue);
  diffProducer.setReportTrees(this.reportTrees);
  diffProducer.setRecursive(this.recursive);
  final List<RuntimeException> producerErrors=new LinkedList<>();
  Thread producerThread=new Thread(){
    @Override public void run(){
      Consumer consumer=diffProducer;
      if (customFilter != null) {
        consumer=new DiffTreeVisitor.FilteringConsumer(consumer,customFilter);
      }
      if (changeTypeFilter != null) {
        consumer=new ChangeTypeFilteringDiffConsumer(changeTypeFilter,consumer);
      }
      if (boundsFilter != null) {
        consumer=new BoundsFilteringDiffConsumer(boundsFilter,consumer,stagingDatabase());
      }
      if (!pathFilters.isEmpty()) {
        consumer=new PathFilteringDiffConsumer(pathFilters,consumer);
      }
      try {
        visitor.walk(consumer);
      }
 catch (      RuntimeException e) {
        LOGGER.error("String_Node_Str",e);
        producerErrors.add(e);
        diffProducer.finished=true;
      }
    }
  }
;
  producerThread.setDaemon(true);
  producerThread.start();
  Iterator<DiffEntry> consumerIterator=new AbstractIterator<DiffEntry>(){
    @Override protected DiffEntry computeNext(){
      if (!producerErrors.isEmpty()) {
        throw new RuntimeException("String_Node_Str",producerErrors.get(0));
      }
      BlockingQueue<DiffEntry> entries=queue;
      boolean finished=diffProducer.isFinished();
      boolean empty=entries.isEmpty();
      while (!finished || !empty) {
        try {
          DiffEntry entry=entries.poll(10,TimeUnit.MILLISECONDS);
          if (entry != null) {
            return entry;
          }
          finished=diffProducer.isFinished();
          empty=entries.isEmpty();
        }
 catch (        InterruptedException e) {
          throw Throwables.propagate(e);
        }
      }
      return endOfData();
    }
    @Override protected void finalize(){
      diffProducer.finished=true;
    }
  }
;
  return consumerIterator;
}

Fixed version (ground truth):
/** 
 * Finds differences between the two specified trees.
 * @return an iterator to a set of differences between the two trees
 * @see DiffEntry
 */
@Override protected Iterator<DiffEntry> _call() throws IllegalArgumentException {
  checkNotNull(oldRefSpec,"String_Node_Str");
  checkNotNull(newRefSpec,"String_Node_Str");
  final RevTree oldTree=resolveTree(oldRefSpec);
  final RevTree newTree=resolveTree(newRefSpec);
  if (oldTree.equals(newTree)) {
    return Iterators.emptyIterator();
  }
  ObjectDatabase leftSource=resolveSource(oldTree.getId());
  ObjectDatabase rightSource=resolveSource(newTree.getId());
  final DiffTreeVisitor visitor=new DiffTreeVisitor(oldTree,newTree,leftSource,rightSource);
  final BlockingQueue<DiffEntry> queue=new ArrayBlockingQueue<>(100);
  final DiffEntryProducer diffProducer=new DiffEntryProducer(queue);
  diffProducer.setReportTrees(this.reportTrees);
  diffProducer.setRecursive(this.recursive);
  final List<RuntimeException> producerErrors=new LinkedList<>();
  Thread producerThread=new Thread("String_Node_Str"){
    @Override public void run(){
      Consumer consumer=diffProducer;
      if (customFilter != null) {
        consumer=new DiffTreeVisitor.FilteringConsumer(consumer,customFilter);
      }
      if (changeTypeFilter != null) {
        consumer=new ChangeTypeFilteringDiffConsumer(changeTypeFilter,consumer);
      }
      if (boundsFilter != null) {
        consumer=new BoundsFilteringDiffConsumer(boundsFilter,consumer,stagingDatabase());
      }
      if (!pathFilters.isEmpty()) {
        consumer=new PathFilteringDiffConsumer(pathFilters,consumer);
      }
      try {
        visitor.walk(consumer);
      }
 catch (      RuntimeException e) {
        LOGGER.error("String_Node_Str",e);
        producerErrors.add(e);
      }
 finally {
        diffProducer.finished=true;
      }
    }
  }
;
  producerThread.setDaemon(true);
  producerThread.start();
  Iterator<DiffEntry> consumerIterator=new AbstractIterator<DiffEntry>(){
    @Override protected DiffEntry computeNext(){
      if (!producerErrors.isEmpty()) {
        throw new RuntimeException("String_Node_Str",producerErrors.get(0));
      }
      BlockingQueue<DiffEntry> entries=queue;
      boolean finished=diffProducer.isFinished();
      boolean empty=entries.isEmpty();
      while (!finished || !empty) {
        try {
          DiffEntry entry=entries.poll(10,TimeUnit.MILLISECONDS);
          if (entry != null) {
            return entry;
          }
          finished=diffProducer.isFinished();
          empty=entries.isEmpty();
        }
 catch (        InterruptedException e) {
          throw Throwables.propagate(e);
        }
      }
      return endOfData();
    }
    @Override protected void finalize(){
      diffProducer.finished=true;
    }
  }
;
  return consumerIterator;
}