Program: 4207
Project: 4207
Buggy source:
private List<Integer> generateDayCandidatesQuestionMarkNotSupportedUsingDoWAndDoM(int year,int month,WeekDay mondayDoWValue){
  LocalDate date=LocalDate.of(year,month,1);
  int lengthOfMonth=date.lengthOfMonth();
  Set<Integer> candidates=new HashSet<>();
  if (daysOfMonthCronField.getExpression() instanceof Always && daysOfWeekCronField.getExpression() instanceof Always) {
    candidates.addAll(createDayOfMonthValueGeneratorInstance(daysOfMonthCronField,year,month).generateCandidates(1,lengthOfMonth));
  }
 else   if (daysOfMonthCronField.getExpression() instanceof Always) {
    candidates.addAll(createDayOfWeekValueGeneratorInstance(daysOfWeekCronField,year,month,mondayDoWValue).generateCandidates(1,lengthOfMonth));
  }
 else   if (daysOfWeekCronField.getExpression() instanceof Always) {
    candidates.addAll(createDayOfMonthValueGeneratorInstance(daysOfMonthCronField,year,month).generateCandidates(1,lengthOfMonth));
  }
 else {
    candidates.addAll(createDayOfWeekValueGeneratorInstance(daysOfWeekCronField,year,month,mondayDoWValue).generateCandidates(1,lengthOfMonth));
    candidates.addAll(createDayOfMonthValueGeneratorInstance(daysOfMonthCronField,year,month).generateCandidates(1,lengthOfMonth));
  }
  List<Integer> candidatesList=new ArrayList<>(candidates);
  Collections.sort(candidatesList);
  return candidatesList;
}

Fixed version (ground truth):
private List<Integer> generateDayCandidatesQuestionMarkNotSupportedUsingDoWAndDoM(int year,int month,WeekDay mondayDoWValue){
  LocalDate date=LocalDate.of(year,month,1);
  int lengthOfMonth=date.lengthOfMonth();
  Set<Integer> candidates=new HashSet<>();
  if (daysOfMonthCronField.getExpression() instanceof Always && daysOfWeekCronField.getExpression() instanceof Always) {
    candidates.addAll(createDayOfMonthValueGeneratorInstance(daysOfMonthCronField,year,month).generateCandidates(1,lengthOfMonth));
  }
 else   if (daysOfMonthCronField.getExpression() instanceof Always) {
    candidates.addAll(createDayOfWeekValueGeneratorInstance(daysOfWeekCronField,year,month,mondayDoWValue).generateCandidates(1,lengthOfMonth));
  }
 else   if (daysOfWeekCronField.getExpression() instanceof Always) {
    candidates.addAll(createDayOfMonthValueGeneratorInstance(daysOfMonthCronField,year,month).generateCandidates(1,lengthOfMonth));
  }
 else {
    List<Integer> dayOfWeekCandidates=createDayOfWeekValueGeneratorInstance(daysOfWeekCronField,year,month,mondayDoWValue).generateCandidates(1,lengthOfMonth);
    List<Integer> dayOfMonthCandidates=createDayOfMonthValueGeneratorInstance(daysOfMonthCronField,year,month).generateCandidates(1,lengthOfMonth);
    if (cronDefinition.isMatchDayOfWeekAndDayOfMonth()) {
      Set<Integer> dayOfWeekCandidatesSet=Sets.newHashSet(dayOfWeekCandidates);
      Set<Integer> dayOfMonthCandidatesSet=Sets.newHashSet(dayOfMonthCandidates);
      candidates.addAll(Sets.intersection(dayOfMonthCandidatesSet,dayOfWeekCandidatesSet));
    }
 else {
      candidates.addAll(dayOfWeekCandidates);
      candidates.addAll(dayOfMonthCandidates);
    }
  }
  List<Integer> candidatesList=new ArrayList<>(candidates);
  Collections.sort(candidatesList);
  return candidatesList;
}