Program: 41941
Project: 41941
Buggy source:
public boolean execute(ICommandSender sender,String[] args){
  if (args.length != 2) {
    sender.sendMessage(getUsage());
    return true;
  }
  if (args[1].length() > 16) {
    sender.sendMessage(C("String_Node_Str"));
  }
  if ("String_Node_Str".equals(args[1]) && plugin.getConfig().getBoolean("String_Node_Str")) {
    sender.sendMessage(C("String_Node_Str"));
    return true;
  }
  IPlayer player=(IPlayer)sender;
  if (player.hasPermission(PermissionNames.ADMIN_DENY) || player.hasPermission(PermissionNames.USER_DENY)) {
    IWorld world=player.getWorld();
    if (manager.isPlotWorld(world)) {
      Plot plot=manager.getPlot(player);
      if (plot == null) {
        player.sendMessage(C("String_Node_Str"));
        return true;
      }
      PlotMapInfo pmi=manager.getMap(world);
      String denied;
      IPlayer deniedPlayer=serverBridge.getPlayer(args[1]);
      if ("String_Node_Str".equals(args[1])) {
        denied="String_Node_Str";
      }
 else       if (deniedPlayer == null) {
        player.sendMessage(args[1] + "String_Node_Str");
        return true;
      }
 else {
        denied=deniedPlayer.getUniqueId().toString();
      }
      if (player.getUniqueId().equals(plot.getOwnerId()) || player.hasPermission(PermissionNames.ADMIN_DENY)) {
        if (!"String_Node_Str".equals(denied)) {
          if (plot.getOwnerId().equals(deniedPlayer.getUniqueId())) {
            player.sendMessage(C("String_Node_Str"));
            return true;
          }
        }
        if (plot.isDenied(denied)) {
          player.sendMessage(C("String_Node_Str",args[1]));
        }
 else {
          double price=0.0;
          PlotAddDeniedEvent event=new PlotAddDeniedEvent(world,plot,player,denied);
          if (manager.isEconomyEnabled(pmi)) {
            price=pmi.getDenyPlayerPrice();
            if (serverBridge.has(player,price)) {
              plugin.getEventBus().post(event);
              if (event.isCancelled()) {
                return true;
              }
              EconomyResponse er=serverBridge.withdrawPlayer(player,price);
              if (!er.transactionSuccess()) {
                player.sendMessage(er.errorMessage);
                plugin.getLogger().warning(er.errorMessage);
                return true;
              }
            }
 else {
              player.sendMessage(C("String_Node_Str") + "String_Node_Str" + C("String_Node_Str")+ "String_Node_Str"+ serverBridge.getEconomy().get().format(price));
              return true;
            }
          }
 else {
            plugin.getEventBus().post(event);
          }
          if (!event.isCancelled()) {
            plot.addDenied(denied);
            plot.removeMember(denied);
            if ("String_Node_Str".equals(denied)) {
              List<IPlayer> playersInPlot=manager.getPlayersInPlot(plot.getId(),world);
              for (              IPlayer iPlayer : playersInPlot) {
                if (plot.isMember(iPlayer.getUniqueId()).isPresent()) {
                  continue;
                }
                iPlayer.setLocation(manager.getPlotHome(plot.getId(),player.getWorld()));
              }
              player.sendMessage(denied + "String_Node_Str" + C("String_Node_Str","String_Node_Str"));
            }
 else             if (deniedPlayer != null && deniedPlayer.getWorld().equals(world)) {
              PlotId plotId=manager.getPlotId(deniedPlayer);
              if (plot.getId().equals(plotId)) {
                deniedPlayer.setLocation(manager.getPlotHome(plot.getId(),player.getWorld()));
              }
              player.sendMessage(denied + "String_Node_Str" + C("String_Node_Str",deniedPlayer.getName()));
            }
            if (isAdvancedLogging()) {
              plugin.getLogger().info(player.getName() + "String_Node_Str" + C("String_Node_Str")+ "String_Node_Str"+ denied+ "String_Node_Str"+ C("String_Node_Str")+ "String_Node_Str"+ plot.getId().getID());
            }
          }
        }
      }
 else {
        player.sendMessage(C("String_Node_Str") + "String_Node_Str" + plot.getId().getID()+ "String_Node_Str"+ C("String_Node_Str"));
      }
    }
 else {
      player.sendMessage(C("String_Node_Str"));
    }
  }
 else {
    return false;
  }
  return true;
}

Fixed version (ground truth):
public boolean execute(ICommandSender sender,String[] args){
  if (args.length != 2) {
    sender.sendMessage(getUsage());
    return true;
  }
  if (args[1].length() > 16) {
    sender.sendMessage(C("String_Node_Str"));
  }
  if ("String_Node_Str".equals(args[1]) && plugin.getConfig().getBoolean("String_Node_Str")) {
    sender.sendMessage(C("String_Node_Str"));
    return true;
  }
  IPlayer player=(IPlayer)sender;
  if (player.hasPermission(PermissionNames.ADMIN_DENY) || player.hasPermission(PermissionNames.USER_DENY)) {
    IWorld world=player.getWorld();
    if (manager.isPlotWorld(world)) {
      Plot plot=manager.getPlot(player);
      if (plot == null) {
        player.sendMessage(C("String_Node_Str"));
        return true;
      }
      PlotMapInfo pmi=manager.getMap(world);
      String denied;
      IPlayer deniedPlayer=serverBridge.getPlayer(args[1]);
      if ("String_Node_Str".equals(args[1])) {
        denied="String_Node_Str";
      }
 else       if (deniedPlayer == null) {
        player.sendMessage(args[1] + "String_Node_Str");
        return true;
      }
 else {
        denied=deniedPlayer.getUniqueId().toString();
      }
      if (player.getUniqueId().equals(plot.getOwnerId()) || player.hasPermission(PermissionNames.ADMIN_DENY)) {
        if (!"String_Node_Str".equals(denied)) {
          if (plot.getOwnerId().equals(deniedPlayer.getUniqueId())) {
            player.sendMessage(C("String_Node_Str"));
            return true;
          }
        }
        if (plot.isDenied(denied)) {
          player.sendMessage(C("String_Node_Str",args[1]));
        }
 else {
          double price=0.0;
          PlotAddDeniedEvent event=new PlotAddDeniedEvent(world,plot,player,denied);
          if (manager.isEconomyEnabled(pmi)) {
            price=pmi.getDenyPlayerPrice();
            if (serverBridge.has(player,price)) {
              plugin.getEventBus().post(event);
              if (event.isCancelled()) {
                return true;
              }
              EconomyResponse er=serverBridge.withdrawPlayer(player,price);
              if (!er.transactionSuccess()) {
                player.sendMessage(er.errorMessage);
                plugin.getLogger().warning(er.errorMessage);
                return true;
              }
            }
 else {
              player.sendMessage(C("String_Node_Str") + "String_Node_Str" + C("String_Node_Str")+ "String_Node_Str"+ serverBridge.getEconomy().get().format(price));
              return true;
            }
          }
 else {
            plugin.getEventBus().post(event);
          }
          if (!event.isCancelled()) {
            plot.addDenied(denied);
            plot.removeMember(denied);
            if ("String_Node_Str".equals(denied)) {
              List<IPlayer> playersInPlot=manager.getPlayersInPlot(plot.getId(),world);
              for (              IPlayer iPlayer : playersInPlot) {
                if (plot.isMember(iPlayer.getUniqueId()).isPresent()) {
                  continue;
                }
                iPlayer.setLocation(manager.getPlotHome(plot.getId(),player.getWorld()));
              }
              player.sendMessage(denied + "String_Node_Str" + C("String_Node_Str","String_Node_Str"));
            }
 else             if (deniedPlayer != null && deniedPlayer.getWorld().equals(world)) {
              PlotId plotId=manager.getPlotId(deniedPlayer);
              if (plot.getId().equals(plotId)) {
                deniedPlayer.setLocation(manager.getPlotHome(plot.getId(),player.getWorld()));
              }
              player.sendMessage(C("String_Node_Str",args[1]));
            }
            if (isAdvancedLogging()) {
              plugin.getLogger().info(player.getName() + "String_Node_Str" + C("String_Node_Str")+ "String_Node_Str"+ args[1]+ "String_Node_Str"+ C("String_Node_Str")+ "String_Node_Str"+ plot.getId().getID());
            }
          }
        }
      }
 else {
        player.sendMessage(C("String_Node_Str") + "String_Node_Str" + plot.getId().getID()+ "String_Node_Str"+ C("String_Node_Str"));
      }
    }
 else {
      player.sendMessage(C("String_Node_Str"));
    }
  }
 else {
    return false;
  }
  return true;
}