Program: 61407
Project: 61407
Buggy source:
@Override public Candidates combineValues(){
  final Candidates result=new Candidates();
  List<String> collectedTests=new ArrayList<>(values.keySet());
  Collections.sort(collectedTests,new Comparator<String>(){
    @Override public int compare(    String s,    String t1){
      if (values.get(t1).isEmpty()) {
        return -1;
      }
      if (values.get(s).isEmpty()) {
        return 1;
      }
      return values.get(t1).get(0).size() - values.get(s).get(0).size();
    }
  }
);
  for (int i=0; i < collectedTests.size(); i++) {
    final String key=collectedTests.get(i);
    List<Candidates> listValue=values.get(key);
    for (    Candidates expressions : listValue) {
      for (      Expression expression : expressions) {
        expression.getValue().setConstant(isConstant(expression));
      }
    }
  }
  long currentTime=System.currentTimeMillis();
  Candidates lastCollectedValues=null;
  for (int k=0; k < collectedTests.size(); k++) {
    final String key=collectedTests.get(k);
    List<Candidates> listValue=values.get(key);
    currentTime=System.currentTimeMillis();
    for (int i=0; i < listValue.size(); i++) {
      Candidates eexps=listValue.get(i);
      if (eexps == null) {
        continue;
      }
      if (lastCollectedValues != null && lastCollectedValues.intersection(eexps,false).size() == eexps.size()) {
        continue;
      }
      lastCollectedValues=eexps;
      if (nopolContext.isSortExpressions()) {
        Collections.sort(eexps,Collections.reverseOrder());
      }
      currentTime=System.currentTimeMillis();
      for (int j=0; j < eexps.size(); j++) {
        Expression expression=eexps.get(j);
        if (expression == null || expression.getValue() == null) {
          continue;
        }
        if (checkExpression(key,i,expression)) {
          result.add(expression);
          if (nopolContext.isOnlyOneSynthesisResult()) {
            return result;
          }
        }
      }
      DataCombinerModified combiner=new DataCombinerModified();
      final int iterationNumber=i;
      combiner.addCombineListener(new DataCombinerModified.CombineListener(){
        @Override public boolean check(        Expression expression){
          if (checkExpression(key,iterationNumber,expression)) {
            return true;
          }
          return false;
        }
      }
);
      currentTime=System.currentTimeMillis();
      long maxCombinerTime=TimeUnit.SECONDS.toMillis(10);
      Candidates result1=combiner.combine(eexps,null,maxCombinerTime,nopolContext);
      result.addAll(result1);
      if (result.size() > 0) {
        if (nopolContext.isOnlyOneSynthesisResult()) {
        }
      }
    }
  }
  return result;
}

Fixed version (ground truth):
@Override public Candidates combineValues(){
  final Candidates result=new Candidates();
  List<String> collectedTests=new ArrayList<>(values.keySet());
  Collections.sort(collectedTests,new Comparator<String>(){
    @Override public int compare(    String s,    String t1){
      if (values.get(t1).isEmpty()) {
        return -1;
      }
      if (values.get(s).isEmpty()) {
        return 1;
      }
      return values.get(t1).get(0).size() - values.get(s).get(0).size();
    }
  }
);
  for (int i=0; i < collectedTests.size(); i++) {
    final String key=collectedTests.get(i);
    List<Candidates> listValue=values.get(key);
    for (    Candidates expressions : listValue) {
      for (      Expression expression : expressions) {
        expression.getValue().setConstant(isConstant(expression));
      }
    }
  }
  long currentTime=System.currentTimeMillis();
  Candidates lastCollectedValues=null;
  for (int k=0; k < collectedTests.size(); k++) {
    final String key=collectedTests.get(k);
    List<Candidates> listValue=values.get(key);
    currentTime=System.currentTimeMillis();
    for (int i=0; i < listValue.size(); i++) {
      Candidates eexps=listValue.get(i);
      if (eexps == null) {
        continue;
      }
      if (lastCollectedValues != null && lastCollectedValues.intersection(eexps,false).size() == eexps.size()) {
        continue;
      }
      lastCollectedValues=eexps;
      if (nopolContext.isSortExpressions()) {
        Collections.sort(eexps,Collections.reverseOrder());
      }
      currentTime=System.currentTimeMillis();
      for (int j=0; j < eexps.size(); j++) {
        Expression expression=eexps.get(j);
        if (expression == null || expression.getValue() == null) {
          continue;
        }
        if (checkExpression(key,i,expression)) {
          result.add(expression);
          if (nopolContext.isOnlyOneSynthesisResult()) {
            return result;
          }
        }
      }
      DataCombinerModified combiner=new DataCombinerModified();
      final int iterationNumber=i;
      combiner.addCombineListener(new DataCombinerModified.CombineListener(){
        @Override public boolean check(        Expression expression){
          if (checkExpression(key,iterationNumber,expression)) {
            result.add(expression);
            return true;
          }
          return false;
        }
      }
);
      currentTime=System.currentTimeMillis();
      long maxCombinerTime=TimeUnit.SECONDS.toMillis(10);
      Candidates result1=combiner.combine(eexps,null,maxCombinerTime,nopolContext);
    }
  }
  return result;
}