Program: 52889
Project: 52889
Buggy source:
private List<SimpleFeature> inputFeatureHandler(SimpleFeatureCollection inputCollection,String featureName,int level,SimpleFeatureType outputFeatureType,Multimap<String,String> relation){
  GeometryFactory geometryFactory=JTSFactoryFinder.getGeometryFactory();
  List<Geometry> geometryList=new ArrayList<Geometry>();
  SimpleFeatureIterator inputFeatures=inputCollection.features();
  SimpleFeatureBuilder featureBuilder=new SimpleFeatureBuilder(outputFeatureType);
  Multimap<String,String> reverted=ArrayListMultimap.create();
  Geometry newGeom=null;
  String country;
  if (!exceptionList.contains(featureName)) {
    if (level == 1) {
      country=(String)Multimaps.invertFrom(relation,reverted).get(featureName).toArray()[0];
synchronized (this) {
        LOG.log(Level.INFO,"String_Node_Str" + featureName + "String_Node_Str"+ country+ "String_Node_Str"+ countryCount.incrementAndGet()+ "String_Node_Str"+ relation.keySet().size()+ "String_Node_Str");
      }
    }
 else {
      country=featureName;
synchronized (this) {
        LOG.log(Level.INFO,"String_Node_Str" + country + "String_Node_Str"+ countryCount.incrementAndGet()+ "String_Node_Str"+ relation.keySet().size()+ "String_Node_Str");
      }
    }
  }
  if (level == 1) {
    while (inputFeatures.hasNext()) {
      SimpleFeature feature=inputFeatures.next();
      if (feature.getAttribute(6).equals(featureName))       geometryList.add((Geometry)feature.getAttribute(0));
    }
  }
 else {
    while (inputFeatures.hasNext()) {
      SimpleFeature feature=inputFeatures.next();
      if (((String)feature.getAttribute(2)).split("String_Node_Str")[1].trim().equals(featureName))       geometryList.add((Geometry)feature.getAttribute(0));
    }
  }
  inputFeatures.close();
  try {
    newGeom=geometryFactory.buildGeometry(geometryList).union().getBoundary();
  }
 catch (  Exception e) {
    LOG.log(Level.INFO,"String_Node_Str" + featureName + "String_Node_Str"+ e.getMessage()+ "String_Node_Str");
    newGeom=geometryFactory.buildGeometry(geometryList).buffer(0);
  }
  featureBuilder.add(newGeom);
  if (level == 1) {
    featureBuilder.add(featureName);
    featureBuilder.add(featureName + "String_Node_Str" + Multimaps.invertFrom(relation,reverted).get(featureName).toArray()[0]);
  }
 else   featureBuilder.add(featureName);
  SimpleFeature feature=featureBuilder.buildFeature(null);
  List<SimpleFeature> features=new ArrayList<SimpleFeature>();
  features.add(feature);
  return features;
}

Fixed version (ground truth):
private List<SimpleFeature> inputFeatureHandler(SimpleFeatureCollection inputCollection,String featureName,int level,SimpleFeatureType outputFeatureType,Multimap<String,String> relation){
  GeometryFactory geometryFactory=JTSFactoryFinder.getGeometryFactory();
  List<Geometry> geometryList=new ArrayList<Geometry>();
  SimpleFeatureIterator inputFeatures=inputCollection.features();
  SimpleFeatureBuilder featureBuilder=new SimpleFeatureBuilder(outputFeatureType);
  Multimap<String,String> reverted=ArrayListMultimap.create();
  Geometry newGeom=null;
  String country;
  reverted=Multimaps.invertFrom(relation,reverted);
  if (!exceptionList.contains(featureName)) {
    if (level == 1) {
      country=(String)reverted.get(featureName).toArray()[0];
synchronized (this) {
        LOG.log(Level.INFO,"String_Node_Str" + featureName + "String_Node_Str"+ country+ "String_Node_Str"+ countryCount.incrementAndGet()+ "String_Node_Str"+ reverted.keySet().size()+ "String_Node_Str");
      }
    }
 else {
      country=featureName;
synchronized (this) {
        LOG.log(Level.INFO,"String_Node_Str" + country + "String_Node_Str"+ countryCount.incrementAndGet()+ "String_Node_Str"+ relation.keySet().size()+ "String_Node_Str");
      }
    }
  }
  if (level == 1) {
    while (inputFeatures.hasNext()) {
      SimpleFeature feature=inputFeatures.next();
      if (feature.getAttribute(6).equals(featureName))       geometryList.add((Geometry)feature.getAttribute(0));
    }
  }
 else {
    while (inputFeatures.hasNext()) {
      SimpleFeature feature=inputFeatures.next();
      if (((String)feature.getAttribute(2)).replace(feature.getAttribute(1) + "String_Node_Str","String_Node_Str").equals(featureName))       geometryList.add((Geometry)feature.getAttribute(0));
    }
  }
  inputFeatures.close();
  try {
    newGeom=geometryFactory.buildGeometry(geometryList).union().getBoundary();
  }
 catch (  Exception e) {
    LOG.log(Level.INFO,"String_Node_Str" + featureName + "String_Node_Str"+ e.getMessage()+ "String_Node_Str");
    newGeom=geometryFactory.buildGeometry(geometryList).buffer(0);
  }
  featureBuilder.add(newGeom);
  if (level == 1) {
    featureBuilder.add(featureName);
    featureBuilder.add(featureName + "String_Node_Str" + reverted.get(featureName).toArray()[0]);
  }
 else   featureBuilder.add(featureName);
  SimpleFeature feature=featureBuilder.buildFeature(null);
  List<SimpleFeature> features=new ArrayList<SimpleFeature>();
  features.add(feature);
  return features;
}