Program: 56541
Project: 56541
Buggy source:
@Override public EvaluationResult evaluate(FormulaExpression expr,FormulaEvaluationContext context){
  if (expr.hasError()) {
    return new EvaluationResultImpl(ResultType.ERROR,new ErrorValue(ErrorValue.INVALID_FORMULA));
  }
  EvaluationResult result=null;
  try {
    NBook book=context.getBook();
    EvalBook evalBook=null;
    WorkbookEvaluator evaluator=null;
    BookSeriesAdv bookSeries=(BookSeriesAdv)book.getBookSeries();
    NBook[] books=bookSeries.getBooks().toArray(new NBook[0]);
    String[] bookNames=new String[books.length];
    WorkbookEvaluator[] evaluators=new WorkbookEvaluator[books.length];
    for (int i=0; i < books.length; ++i) {
      bookNames[i]=books[i].getBookName();
      EvalBook eb=new EvalBook(books[i]);
      evaluators[i]=new WorkbookEvaluator(eb,null,null);
      if (context.getBook() == books[i]) {
        evalBook=eb;
        evaluator=evaluators[i];
      }
    }
    CollaboratingWorkbooksEnvironment.setup(bookNames,evaluators);
    if (evalBook == null || evaluator == null) {
      return new EvaluationResultImpl(ResultType.ERROR,"String_Node_Str");
    }
    ValueEval value=null;
    int currentSheetIndex=book.getSheetIndex(context.getSheet());
    if (context.getCell().isNull()) {
      value=evaluator.evaluate(currentSheetIndex,expr.getFormulaString(),false);
    }
 else {
      NCell cell=context.getCell();
      EvaluationCell evalCell=evalBook.getSheet(currentSheetIndex).getCell(cell.getRowIndex(),cell.getColumnIndex());
      value=evaluator.evaluate(evalCell);
    }
    if (value instanceof ErrorEval) {
      int code=((ErrorEval)value).getErrorCode();
      result=new EvaluationResultImpl(ResultType.ERROR,new ErrorValue((byte)code));
    }
 else     if (value instanceof StringEval) {
      result=new EvaluationResultImpl(ResultType.SUCCESS,((StringEval)value).getStringValue());
    }
 else     if (value instanceof NumberEval) {
      result=new EvaluationResultImpl(ResultType.SUCCESS,((NumberEval)value).getNumberValue());
    }
 else     if (value instanceof ValuesEval) {
      ValueEval[] values=((ValuesEval)value).getValueEvals();
      Object[] array=new Object[values.length];
      for (int i=0; i < values.length; ++i) {
        if (value instanceof StringEval) {
          array[i]=((StringEval)values[i]).getStringValue();
        }
 else         if (value instanceof NumberEval) {
          array[i]=((NumberEval)values[i]).getNumberValue();
        }
 else {
          throw new Exception("String_Node_Str" + array[i]);
        }
      }
      return new EvaluationResultImpl(ResultType.SUCCESS,array);
    }
 else {
      throw new Exception("String_Node_Str" + value);
    }
  }
 catch (  Exception e) {
    logger.log(Level.SEVERE,e.getMessage(),e);
    result=new EvaluationResultImpl(ResultType.ERROR,new ErrorValue(ErrorValue.INVALID_FORMULA));
  }
  return result;
}

Fixed version (ground truth):
@Override public EvaluationResult evaluate(FormulaExpression expr,FormulaEvaluationContext context){
  if (expr.hasError()) {
    return new EvaluationResultImpl(ResultType.ERROR,new ErrorValue(ErrorValue.INVALID_FORMULA));
  }
  EvaluationResult result=null;
  try {
    NBook book=context.getBook();
    EvalBook evalBook=null;
    WorkbookEvaluator evaluator=null;
    BookSeriesAdv bookSeries=(BookSeriesAdv)book.getBookSeries();
    NBook[] books=bookSeries.getBooks().toArray(new NBook[0]);
    String[] bookNames=new String[books.length];
    WorkbookEvaluator[] evaluators=new WorkbookEvaluator[books.length];
    for (int i=0; i < books.length; ++i) {
      bookNames[i]=books[i].getBookName();
      EvalBook eb=new EvalBook(books[i]);
      evaluators[i]=new WorkbookEvaluator(eb,null,null);
      if (context.getBook() == books[i]) {
        evalBook=eb;
        evaluator=evaluators[i];
      }
    }
    CollaboratingWorkbooksEnvironment.setup(bookNames,evaluators);
    if (evalBook == null || evaluator == null) {
      return new EvaluationResultImpl(ResultType.ERROR,"String_Node_Str");
    }
    ValueEval value=null;
    int currentSheetIndex=book.getSheetIndex(context.getSheet());
    NCell cell=context.getCell();
    if (cell == null || cell.isNull()) {
      value=evaluator.evaluate(currentSheetIndex,expr.getFormulaString(),true);
    }
 else {
      EvaluationCell evalCell=evalBook.getSheet(currentSheetIndex).getCell(cell.getRowIndex(),cell.getColumnIndex());
      value=evaluator.evaluate(evalCell);
    }
    if (value instanceof ErrorEval) {
      int code=((ErrorEval)value).getErrorCode();
      result=new EvaluationResultImpl(ResultType.ERROR,new ErrorValue((byte)code));
    }
 else     if (value instanceof BlankEval) {
      result=new EvaluationResultImpl(ResultType.SUCCESS,"String_Node_Str");
    }
 else     if (value instanceof StringEval) {
      result=new EvaluationResultImpl(ResultType.SUCCESS,((StringEval)value).getStringValue());
    }
 else     if (value instanceof NumberEval) {
      result=new EvaluationResultImpl(ResultType.SUCCESS,((NumberEval)value).getNumberValue());
    }
 else     if (value instanceof ValuesEval) {
      ValueEval[] values=((ValuesEval)value).getValueEvals();
      Object[] array=new Object[values.length];
      for (int i=0; i < values.length; ++i) {
        array[i]=getResolvedValue(values[i]);
      }
      result=new EvaluationResultImpl(ResultType.SUCCESS,array);
    }
 else     if (value instanceof AreaEval) {
      List<Object> list=new ArrayList<Object>();
      AreaEval area=(AreaEval)value;
      for (int r=0; r < area.getHeight(); ++r) {
        for (int c=0; c < area.getWidth(); ++c) {
          ValueEval v=area.getValue(r,c);
          list.add(getResolvedValue(v));
        }
      }
      result=new EvaluationResultImpl(ResultType.SUCCESS,list);
    }
 else     if (value instanceof RefEval) {
      ValueEval ve=((RefEval)value).getInnerValueEval();
      Object v=getResolvedValue(ve);
      result=new EvaluationResultImpl(ResultType.SUCCESS,v);
    }
 else {
      throw new Exception("String_Node_Str" + value);
    }
  }
 catch (  Exception e) {
    logger.log(Level.SEVERE,e.getMessage(),e);
    result=new EvaluationResultImpl(ResultType.ERROR,new ErrorValue(ErrorValue.INVALID_FORMULA));
  }
  return result;
}