Program: 58027
Project: 58027
Buggy source:
@Override public boolean execute(final PlotPlayer plr,final String... args){
  if (PlotSquared.economy == null) {
    return sendMessage(plr,C.ECON_DISABLED);
  }
  final Location loc=plr.getLocation();
  final String world=loc.getWorld();
  if (!PlotSquared.isPlotWorld(world)) {
    return sendMessage(plr,C.NOT_IN_PLOT_WORLD);
  }
  Plot plot;
  if (args.length > 0) {
    try {
      final String[] split=args[0].split("String_Node_Str");
      final PlotId id=new PlotId(Integer.parseInt(split[0]),Integer.parseInt(split[1]));
      plot=MainUtil.getPlot(world,id);
    }
 catch (    final Exception e) {
      return sendMessage(plr,C.NOT_VALID_PLOT_ID);
    }
  }
 else {
    plot=MainUtil.getPlot(loc);
  }
  if (plot == null) {
    return sendMessage(plr,C.NOT_IN_PLOT);
  }
  final int currentPlots=Settings.GLOBAL_LIMIT ? MainUtil.getPlayerPlotCount(plr) : MainUtil.getPlayerPlotCount(world,plr);
  if (currentPlots >= MainUtil.getAllowedPlots(plr)) {
    return sendMessage(plr,C.CANT_CLAIM_MORE_PLOTS);
  }
  if (!plot.hasOwner()) {
    return sendMessage(plr,C.PLOT_UNOWNED);
  }
  if (PlotHandler.isOwner(plot,plr.getUUID())) {
    return sendMessage(plr,C.CANNOT_BUY_OWN);
  }
  final Flag flag=FlagManager.getPlotFlag(plot,"String_Node_Str");
  if (flag == null) {
    return sendMessage(plr,C.NOT_FOR_SALE);
  }
  double initPrice=(double)flag.getValue();
  double price=initPrice;
  final PlotId id=plot.id;
  final PlotId id2=MainUtil.getTopPlot(plot).id;
  final int size=MainUtil.getPlotSelectionIds(id,id2).size();
  final PlotWorld plotworld=PlotSquared.getPlotWorld(world);
  if (plotworld.USE_ECONOMY) {
    price+=plotworld.PLOT_PRICE * size;
    initPrice+=plotworld.SELL_PRICE * size;
  }
  if ((PlotSquared.economy != null) && (price > 0d)) {
    if (EconHandler.getBalance(plr) < price) {
      return sendMessage(plr,C.CANNOT_AFFORD_PLOT,"String_Node_Str" + price);
    }
    EconHandler.withdrawPlayer(plr,price);
    sendMessage(plr,C.REMOVED_BALANCE,price + "String_Node_Str");
    EconHandler.depositPlayer(UUIDHandler.uuidWrapper.getOfflinePlayer(plot.owner),initPrice);
    final PlotPlayer owner=UUIDHandler.getPlayer(plot.owner);
    if (owner != null) {
      sendMessage(plr,C.PLOT_SOLD,plot.id + "String_Node_Str",plr.getName(),initPrice + "String_Node_Str");
    }
    FlagManager.removePlotFlag(plot,"String_Node_Str");
  }
  Plot top=MainUtil.getTopPlot(plot);
  for (  PlotId myId : MainUtil.getPlotSelectionIds(plot.id,top.id)) {
    Plot myPlot=MainUtil.getPlot(plot.world,myId);
    myPlot.owner=plr.getUUID();
    DBFunc.setOwner(plot,myPlot.owner);
  }
  MainUtil.sendMessage(plr,C.CLAIMED);
  return true;
}

Fixed version (ground truth):
@Override public boolean execute(final PlotPlayer plr,final String... args){
  if (EconHandler.manager == null) {
    return sendMessage(plr,C.ECON_DISABLED);
  }
  final Location loc=plr.getLocation();
  final String world=loc.getWorld();
  if (!PlotSquared.isPlotWorld(world)) {
    return sendMessage(plr,C.NOT_IN_PLOT_WORLD);
  }
  Plot plot;
  if (args.length > 0) {
    try {
      final String[] split=args[0].split("String_Node_Str");
      final PlotId id=new PlotId(Integer.parseInt(split[0]),Integer.parseInt(split[1]));
      plot=MainUtil.getPlot(world,id);
    }
 catch (    final Exception e) {
      return sendMessage(plr,C.NOT_VALID_PLOT_ID);
    }
  }
 else {
    plot=MainUtil.getPlot(loc);
  }
  if (plot == null) {
    return sendMessage(plr,C.NOT_IN_PLOT);
  }
  final int currentPlots=Settings.GLOBAL_LIMIT ? MainUtil.getPlayerPlotCount(plr) : MainUtil.getPlayerPlotCount(world,plr);
  if (currentPlots >= MainUtil.getAllowedPlots(plr)) {
    return sendMessage(plr,C.CANT_CLAIM_MORE_PLOTS);
  }
  if (!plot.hasOwner()) {
    return sendMessage(plr,C.PLOT_UNOWNED);
  }
  if (PlotHandler.isOwner(plot,plr.getUUID())) {
    return sendMessage(plr,C.CANNOT_BUY_OWN);
  }
  final Flag flag=FlagManager.getPlotFlag(plot,"String_Node_Str");
  if (flag == null) {
    return sendMessage(plr,C.NOT_FOR_SALE);
  }
  double initPrice=(double)flag.getValue();
  double price=initPrice;
  final PlotId id=plot.id;
  final PlotId id2=MainUtil.getTopPlot(plot).id;
  final int size=MainUtil.getPlotSelectionIds(id,id2).size();
  final PlotWorld plotworld=PlotSquared.getPlotWorld(world);
  if (plotworld.USE_ECONOMY) {
    price+=plotworld.PLOT_PRICE * size;
    initPrice+=plotworld.SELL_PRICE * size;
  }
  if ((EconHandler.manager != null) && (price > 0d)) {
    if (EconHandler.manager.getMoney(plr) < price) {
      return sendMessage(plr,C.CANNOT_AFFORD_PLOT,"String_Node_Str" + price);
    }
    EconHandler.manager.withdrawMoney(plr,price);
    sendMessage(plr,C.REMOVED_BALANCE,price + "String_Node_Str");
    EconHandler.manager.depositMoney(UUIDHandler.uuidWrapper.getOfflinePlayer(plot.owner),initPrice);
    final PlotPlayer owner=UUIDHandler.getPlayer(plot.owner);
    if (owner != null) {
      sendMessage(plr,C.PLOT_SOLD,plot.id + "String_Node_Str",plr.getName(),initPrice + "String_Node_Str");
    }
    FlagManager.removePlotFlag(plot,"String_Node_Str");
  }
  Plot top=MainUtil.getTopPlot(plot);
  for (  PlotId myId : MainUtil.getPlotSelectionIds(plot.id,top.id)) {
    Plot myPlot=MainUtil.getPlot(plot.world,myId);
    myPlot.owner=plr.getUUID();
    DBFunc.setOwner(plot,myPlot.owner);
  }
  MainUtil.sendMessage(plr,C.CLAIMED);
  return true;
}