Program: 178984
Project: 178984
Buggy source:
public void addPiece(){
  int type=(int)(Math.random() * 7);
  if (type == 0) {
    board[0][3]=new Block(0,3,"String_Node_Str",1);
    board[0][4]=new Block(0,4,"String_Node_Str",2);
    board[0][5]=new Block(0,5,"String_Node_Str",3);
    board[0][6]=new Block(0,6,"String_Node_Str",4);
  }
 else   if (type == 1) {
    board[0][3]=new Block(0,3,"String_Node_Str",1);
    board[1][3]=new Block(1,3,"String_Node_Str",2);
    board[1][4]=new Block(1,4,"String_Node_Str",3);
    board[1][5]=new Block(1,5,"String_Node_Str",4);
  }
 else   if (type == 2) {
    board[1][3]=new Block(1,3,"String_Node_Str",1);
    board[1][4]=new Block(1,4,"String_Node_Str",2);
    board[1][5]=new Block(1,5,"String_Node_Str",3);
    board[0][5]=new Block(0,5,"String_Node_Str",4);
  }
 else   if (type == 3) {
    board[0][4]=new Block(0,4,"String_Node_Str",1);
    board[0][5]=new Block(0,5,"String_Node_Str",2);
    board[1][4]=new Block(1,4,"String_Node_Str",3);
    board[1][5]=new Block(1,5,"String_Node_Str",4);
  }
 else   if (type == 4) {
    board[1][3]=new Block(1,3,"String_Node_Str",1);
    board[1][4]=new Block(1,4,"String_Node_Str",2);
    board[0][4]=new Block(0,4,"String_Node_Str",3);
    board[0][5]=new Block(0,5,"String_Node_Str",4);
  }
 else   if (type == 5) {
    board[1][3]=new Block(1,3,"String_Node_Str",1);
    board[1][4]=new Block(1,4,"String_Node_Str",2);
    board[0][4]=new Block(0,4,"String_Node_Str",3);
    board[1][5]=new Block(1,5,"String_Node_Str",4);
  }
 else {
    board[0][3]=new Block(0,3,"String_Node_Str",1);
    board[0][4]=new Block(0,4,"String_Node_Str",2);
    board[1][4]=new Block(1,4,"String_Node_Str",3);
    board[1][5]=new Block(1,5,"String_Node_Str",4);
  }
  int at=0;
  for (int i=0; i < 2; i++) {
    for (int j=3; j < 7; j++) {
      if (board[i][j] != null) {
        piece[at]=board[i][j];
        at++;
      }
    }
  }
}

Fixed version (ground truth):
public void addPiece(){
  int type=(int)(Math.random() * 7);
  if (type == 0) {
    board[0][3]=new Block(0,3,"String_Node_Str",1);
    board[0][4]=new Block(0,4,"String_Node_Str",2);
    board[0][5]=new Block(0,5,"String_Node_Str",3);
    board[0][6]=new Block(0,6,"String_Node_Str",4);
  }
 else   if (type == 1) {
    board[1][3]=new Block(1,3,"String_Node_Str",2);
    board[1][4]=new Block(1,4,"String_Node_Str",3);
    board[1][5]=new Block(1,5,"String_Node_Str",4);
    board[0][3]=new Block(0,3,"String_Node_Str",1);
  }
 else   if (type == 2) {
    board[1][3]=new Block(1,3,"String_Node_Str",1);
    board[1][4]=new Block(1,4,"String_Node_Str",2);
    board[1][5]=new Block(1,5,"String_Node_Str",3);
    board[0][5]=new Block(0,5,"String_Node_Str",4);
  }
 else   if (type == 3) {
    board[1][4]=new Block(1,4,"String_Node_Str",3);
    board[1][5]=new Block(1,5,"String_Node_Str",4);
    board[0][4]=new Block(0,4,"String_Node_Str",1);
    board[0][5]=new Block(0,5,"String_Node_Str",2);
  }
 else   if (type == 4) {
    board[1][3]=new Block(1,3,"String_Node_Str",1);
    board[1][4]=new Block(1,4,"String_Node_Str",2);
    board[0][4]=new Block(0,4,"String_Node_Str",3);
    board[0][5]=new Block(0,5,"String_Node_Str",4);
  }
 else   if (type == 5) {
    board[1][3]=new Block(1,3,"String_Node_Str",1);
    board[1][4]=new Block(1,4,"String_Node_Str",2);
    board[1][5]=new Block(1,5,"String_Node_Str",4);
    board[0][4]=new Block(0,4,"String_Node_Str",3);
  }
 else {
    board[1][4]=new Block(1,4,"String_Node_Str",3);
    board[1][5]=new Block(1,5,"String_Node_Str",4);
    board[0][3]=new Block(0,3,"String_Node_Str",1);
    board[0][4]=new Block(0,4,"String_Node_Str",2);
  }
  int at=0;
  for (int i=0; i < 2; i++) {
    for (int j=3; j < 7; j++) {
      if (board[i][j] != null) {
        piece[at]=board[i][j];
        at++;
      }
    }
  }
}