Program: 49681
Project: 49681
Buggy source:
/** 
 * It does not append + or #
 * @param board
 * @param move
 * @return
 */
public static String toSan(Board board,int move){
  board.generateLegalMoves();
  boolean isLegal=false;
  boolean disambiguate=false;
  boolean fileEqual=false;
  boolean rankEqual=false;
  for (int i=0; i < board.legalMoveCount; i++) {
    int move2=board.legalMoves[i];
    if (move == move2) {
      isLegal=true;
    }
 else     if (getToIndex(move) == getToIndex(move2) && (getPieceMoved(move) == getPieceMoved(move2))) {
      disambiguate=true;
      if ((getFromIndex(move) % 8) == (getFromIndex(move2) % 8)) {
        fileEqual=true;
      }
      if ((getFromIndex(move) / 8) == (getFromIndex(move2) / 8)) {
        rankEqual=true;
      }
    }
  }
  if (move == 0 || move == -1 || !isLegal) {
    return "String_Node_Str";
  }
 else   if (Move.getMoveType(move) == TYPE_KINGSIDE_CASTLING) {
    return Move.isCheck(move) ? "String_Node_Str" : "String_Node_Str";
  }
 else   if (Move.getMoveType(move) == TYPE_QUEENSIDE_CASTLING) {
    return Move.isCheck(move) ? "String_Node_Str" : "String_Node_Str";
  }
  StringBuilder sb=new StringBuilder();
  if (getPieceMoved(move) != Piece.PAWN) {
    sb.append(PIECE_LETTERS_UPPERCASE.charAt(getPieceMoved(move)));
  }
  String fromSq=BitboardUtils.index2Algebraic(Move.getFromIndex(move));
  if (isCapture(move) && getPieceMoved(move) == Piece.PAWN) {
    disambiguate=true;
  }
  if (disambiguate) {
    if (fileEqual && rankEqual) {
      sb.append(fromSq);
    }
 else     if (fileEqual && !rankEqual) {
      sb.append(fromSq.charAt(1));
    }
 else {
      sb.append(fromSq.charAt(0));
    }
  }
  if (isCapture(move)) {
    sb.append("String_Node_Str");
  }
  sb.append(BitboardUtils.index2Algebraic(Move.getToIndex(move)));
  if (isPromotion(move)) {
    sb.append(PIECE_LETTERS_UPPERCASE.charAt(getPiecePromoted(move)));
  }
  if (isCheck(move)) {
    sb.append("String_Node_Str");
  }
  return sb.toString();
}

Fixed version (ground truth):
/** 
 * It does not append + or #
 * @param board
 * @param move
 * @return
 */
public static String toSan(Board board,int move){
  board.generateLegalMoves();
  boolean isLegal=false;
  boolean disambiguate=false;
  boolean fileEqual=false;
  boolean rankEqual=false;
  for (int i=0; i < board.legalMoveCount; i++) {
    int move2=board.legalMoves[i];
    if (move == move2) {
      isLegal=true;
    }
 else     if (getToIndex(move) == getToIndex(move2) && (getPieceMoved(move) == getPieceMoved(move2))) {
      disambiguate=true;
      if ((getFromIndex(move) % 8) == (getFromIndex(move2) % 8)) {
        fileEqual=true;
      }
      if ((getFromIndex(move) / 8) == (getFromIndex(move2) / 8)) {
        rankEqual=true;
      }
    }
  }
  if (move == 0 || move == -1 || !isLegal) {
    return "String_Node_Str";
  }
 else   if (Move.getMoveType(move) == TYPE_KINGSIDE_CASTLING) {
    return Move.isCheck(move) ? "String_Node_Str" : "String_Node_Str";
  }
 else   if (Move.getMoveType(move) == TYPE_QUEENSIDE_CASTLING) {
    return Move.isCheck(move) ? "String_Node_Str" : "String_Node_Str";
  }
  StringBuilder sb=new StringBuilder();
  if (getPieceMoved(move) != Piece.PAWN) {
    sb.append(PIECE_LETTERS_UPPERCASE.charAt(getPieceMoved(move)));
  }
  String fromSq=BitboardUtils.index2Algebraic(Move.getFromIndex(move));
  if (isCapture(move) && getPieceMoved(move) == Piece.PAWN) {
    disambiguate=true;
  }
  if (disambiguate) {
    if (fileEqual && rankEqual) {
      sb.append(fromSq);
    }
 else     if (fileEqual) {
      sb.append(fromSq.charAt(1));
    }
 else {
      sb.append(fromSq.charAt(0));
    }
  }
  if (isCapture(move)) {
    sb.append("String_Node_Str");
  }
  sb.append(BitboardUtils.index2Algebraic(Move.getToIndex(move)));
  if (isPromotion(move)) {
    sb.append(PIECE_LETTERS_UPPERCASE.charAt(getPiecePromoted(move)));
  }
  if (isCheck(move)) {
    sb.append("String_Node_Str");
  }
  return sb.toString();
}