Program: 63373
Project: 63373
Buggy source:
@Override public TupleFilter onSerialize(TupleFilter filter){
  if (filter == null)   return filter;
  if ((filter instanceof CompareTupleFilter) == false)   return filter;
  if (TupleFilter.isEvaluableRecursively(filter) == false)   return ConstantTupleFilter.TRUE;
  CompareTupleFilter compf=(CompareTupleFilter)filter;
  Pair<ColumnTupleFilter,ConstantTupleFilter> pair=compf.getColumnAndConstant();
  ColumnTupleFilter colf=pair.getFirst();
  ConstantTupleFilter constf=pair.getSecond();
  if (colf == null) {
    return filter;
  }
  TblColRef col=colf.getColumn();
  String nullString=nullString(col);
  if (constf == null) {
    compf.setNullString(nullString);
    return filter;
  }
  TupleFilter result;
  CompareTupleFilter newComp=new CompareTupleFilter(compf.getOperator());
  newComp.setNullString(nullString);
  newComp.addChild(colf);
  String firstValue=constf.getValues().iterator().next();
  String v;
switch (newComp.getOperator()) {
case EQ:
case IN:
    Set<String> newValues=Sets.newHashSet();
  for (  String value : constf.getValues()) {
    v=translate(col,value,0);
    if (nullString.equals(v) == false)     newValues.add(v);
  }
if (newValues.isEmpty()) {
  result=ConstantTupleFilter.FALSE;
}
 else {
  newComp.addChild(new ConstantTupleFilter(newValues));
  result=newComp;
}
break;
case NEQ:
v=translate(col,firstValue,0);
if (nullString.equals(v)) {
result=ConstantTupleFilter.TRUE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
case LT:
v=translate(col,firstValue,1);
if (nullString.equals(v)) {
result=ConstantTupleFilter.TRUE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
case LTE:
v=translate(col,firstValue,-1);
if (nullString.equals(v)) {
result=ConstantTupleFilter.FALSE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
case GT:
v=translate(col,firstValue,-1);
if (nullString.equals(v)) {
result=ConstantTupleFilter.TRUE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
case GTE:
v=translate(col,firstValue,1);
if (nullString.equals(v)) {
result=ConstantTupleFilter.FALSE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
default :
throw new IllegalStateException("String_Node_Str" + newComp.getOperator());
}
return result;
}

Fixed version (ground truth):
@Override public TupleFilter onSerialize(TupleFilter filter){
  if (filter == null)   return filter;
  if (filter.getOperator() == FilterOperatorEnum.NOT && TupleFilter.isEvaluableRecursively(filter) == false)   return ConstantTupleFilter.TRUE;
  if ((filter instanceof CompareTupleFilter) == false)   return filter;
  if (TupleFilter.isEvaluableRecursively(filter) == false)   return ConstantTupleFilter.TRUE;
  CompareTupleFilter compf=(CompareTupleFilter)filter;
  Pair<ColumnTupleFilter,ConstantTupleFilter> pair=compf.getColumnAndConstant();
  ColumnTupleFilter colf=pair.getFirst();
  ConstantTupleFilter constf=pair.getSecond();
  if (colf == null) {
    return filter;
  }
  TblColRef col=colf.getColumn();
  String nullString=nullString(col);
  if (constf == null) {
    compf.setNullString(nullString);
    return filter;
  }
  TupleFilter result;
  CompareTupleFilter newComp=new CompareTupleFilter(compf.getOperator());
  newComp.setNullString(nullString);
  newComp.addChild(colf);
  String firstValue=constf.getValues().iterator().next();
  String v;
switch (newComp.getOperator()) {
case EQ:
case IN:
    Set<String> newValues=Sets.newHashSet();
  for (  String value : constf.getValues()) {
    v=translate(col,value,0);
    if (nullString.equals(v) == false)     newValues.add(v);
  }
if (newValues.isEmpty()) {
  result=ConstantTupleFilter.FALSE;
}
 else {
  newComp.addChild(new ConstantTupleFilter(newValues));
  result=newComp;
}
break;
case NEQ:
v=translate(col,firstValue,0);
if (nullString.equals(v)) {
result=ConstantTupleFilter.TRUE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
case LT:
v=translate(col,firstValue,1);
if (nullString.equals(v)) {
result=ConstantTupleFilter.TRUE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
case LTE:
v=translate(col,firstValue,-1);
if (nullString.equals(v)) {
result=ConstantTupleFilter.FALSE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
case GT:
v=translate(col,firstValue,-1);
if (nullString.equals(v)) {
result=ConstantTupleFilter.TRUE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
case GTE:
v=translate(col,firstValue,1);
if (nullString.equals(v)) {
result=ConstantTupleFilter.FALSE;
}
 else {
newComp.addChild(new ConstantTupleFilter(v));
result=newComp;
}
break;
default :
throw new IllegalStateException("String_Node_Str" + newComp.getOperator());
}
return result;
}