Program: 84994
Project: 84994
Buggy source:
public void onBlockDamage(BlockDamageEvent event){
  Player player=event.getPlayer();
  Block block=event.getBlock();
  int dmg=event.getDamageLevel().getLevel();
  if (dmg == 3) {
    mcUsers.getProfile(player).addgather(1);
    if (block.getTypeId() == 1) {
      int t=player.getItemInHand().getTypeId();
      int q;
      if (t == 272 || t == 273 || t == 274 || t == 275) {
        q=3;
      }
 else       if (t == 256 || t == 257 || t == 258 || t == 267) {
        q=2;
      }
 else       if (t == 268 || t == 269 || t == 270 || t == 271) {
        q=4;
      }
 else       if (t == 276 || t == 277 || t == 278 || t == 279) {
        q=1;
      }
 else {
        q=5;
      }
    }
  }
}

Fixed version (ground truth):
public void onBlockDamage(BlockDamageEvent event){
  Player player=event.getPlayer();
  Block block=event.getBlock();
  Location loc=block.getLocation();
  int dmg=event.getDamageLevel().getLevel();
  if (dmg == 3 && !mcConfig.getInstance().isBlockWatched(block)) {
    if (block.getTypeId() == 1) {
      mcUsers.getProfile(player).addgather(1);
      blockProcCheck(block,player);
    }
    if (block.getTypeId() == 16) {
      mcUsers.getProfile(player).addgather(3);
      blockProcCheck(block,player);
    }
    if (block.getTypeId() == 14) {
      mcUsers.getProfile(player).addgather(20);
      blockProcCheck(block,player);
    }
    if (block.getTypeId() == 56) {
      mcUsers.getProfile(player).addgather(50);
      blockProcCheck(block,player);
    }
    if (block.getTypeId() == 15) {
      mcUsers.getProfile(player).addgather(10);
      blockProcCheck(block,player);
    }
    if (block.getTypeId() == 73 || block.getTypeId() == 74) {
      mcUsers.getProfile(player).addgather(15);
      blockProcCheck(block,player);
    }
    if (block.getTypeId() == 21) {
      mcUsers.getProfile(player).addgather(50);
      blockProcCheck(block,player);
    }
    if (block.getTypeId() == 17)     mcUsers.getProfile(player).addwgather(1);
    if (mcUsers.getProfile(player).getwgatheramt() > 10) {
      while (mcUsers.getProfile(player).getwgatheramt() > 10) {
        mcUsers.getProfile(player).removewgather(10);
        mcUsers.getProfile(player).skillUpWoodcutting(1);
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + mcUsers.getProfile(player).getWoodCutting()+ "String_Node_Str");
      }
    }
    if (mcUsers.getProfile(player).getgatheramt() > 50) {
      while (mcUsers.getProfile(player).getgatheramt() > 50) {
        mcUsers.getProfile(player).removegather(50);
        mcUsers.getProfile(player).skillUpMining(1);
        player.sendMessage(ChatColor.YELLOW + "String_Node_Str" + mcUsers.getProfile(player).getMining()+ "String_Node_Str");
      }
    }
    if (block.getTypeId() == 17) {
      if (mcUsers.getProfile(player).getWoodCuttingint() > 1000) {
        Material mat=Material.getMaterial(block.getTypeId());
        byte damage=0;
        ItemStack item=new ItemStack(mat,1,(byte)0,damage);
        block.getWorld().dropItemNaturally(loc,item);
        return;
      }
      if (mcUsers.getProfile(player).getWoodCuttingint() > 750) {
        if ((Math.random() * 10) > 2) {
          Material mat=Material.getMaterial(block.getTypeId());
          byte damage=0;
          ItemStack item=new ItemStack(mat,1,(byte)0,damage);
          block.getWorld().dropItemNaturally(loc,item);
          return;
        }
      }
      if (mcUsers.getProfile(player).getWoodCuttingint() > 300) {
        if ((Math.random() * 10) > 4) {
          Material mat=Material.getMaterial(block.getTypeId());
          byte damage=0;
          ItemStack item=new ItemStack(mat,1,(byte)0,damage);
          block.getWorld().dropItemNaturally(loc,item);
          return;
        }
      }
      if (mcUsers.getProfile(player).getWoodCuttingint() > 100) {
        if ((Math.random() * 10) > 6) {
          Material mat=Material.getMaterial(block.getTypeId());
          byte damage=0;
          ItemStack item=new ItemStack(mat,1,(byte)0,damage);
          block.getWorld().dropItemNaturally(loc,item);
          return;
        }
      }
      if (mcUsers.getProfile(player).getWoodCuttingint() > 10) {
        if ((Math.random() * 10) > 8) {
          Material mat=Material.getMaterial(block.getTypeId());
          byte damage=0;
          ItemStack item=new ItemStack(mat,1,(byte)0,damage);
          block.getWorld().dropItemNaturally(loc,item);
          return;
        }
      }
    }
  }
}