Program: 58122
Project: 58122
Buggy source:
@Override public boolean execute(Player plr,String... args){
  if (!PlayerFunctions.isInPlot(plr)) {
    PlayerFunctions.sendMessage(plr,C.NOT_IN_PLOT);
    return true;
  }
  Plot plot=PlayerFunctions.getCurrentPlot(plr);
  if ((plot == null) || !plot.hasOwner()) {
    PlayerFunctions.sendMessage(plr,C.NO_PLOT_PERMS);
    return false;
  }
  if (!plot.getOwner().equals(plr.getUniqueId())) {
    PlayerFunctions.sendMessage(plr,C.NO_PLOT_PERMS);
    return false;
  }
  if (args.length < 1) {
    PlayerFunctions.sendMessage(plr,C.SUBCOMMAND_SET_OPTIONS_HEADER.s() + StringUtils.join(values,C.BLOCK_LIST_SEPARATER.s()));
    PlayerFunctions.sendMessage(plr,C.DIRECTION.s().replaceAll("String_Node_Str",direction(plr.getLocation().getYaw())));
    return false;
  }
  int direction=-1;
  for (int i=0; i < values.length; i++) {
    if (args[0].equalsIgnoreCase(values[i]) || args[0].equalsIgnoreCase(aliases[i])) {
      direction=i;
      break;
    }
  }
  if (direction == -1) {
    PlayerFunctions.sendMessage(plr,C.SUBCOMMAND_SET_OPTIONS_HEADER.s() + StringUtils.join(values,C.BLOCK_LIST_SEPARATER.s()));
    PlayerFunctions.sendMessage(plr,C.DIRECTION.s().replaceAll("String_Node_Str",direction(plr.getLocation().getYaw())));
    return false;
  }
  World world=plr.getWorld();
  PlotId bot=PlayerFunctions.getBottomPlot(world,plot).id;
  PlotId top=PlayerFunctions.getTopPlot(world,plot).id;
  ArrayList<PlotId> plots;
switch (direction) {
case 0:
    plots=PlayerFunctions.getPlotSelectionIds(plr.getWorld(),new PlotId(bot.x,bot.y - 1),new PlotId(top.x,top.y));
  break;
case 1:
plots=PlayerFunctions.getPlotSelectionIds(plr.getWorld(),new PlotId(bot.x,bot.y),new PlotId(top.x + 1,top.y));
break;
case 2:
plots=PlayerFunctions.getPlotSelectionIds(plr.getWorld(),new PlotId(bot.x,bot.y),new PlotId(top.x,top.y + 1));
break;
case 3:
plots=PlayerFunctions.getPlotSelectionIds(plr.getWorld(),new PlotId(bot.x - 1,bot.y),new PlotId(top.x,top.y));
break;
default :
return false;
}
for (PlotId myid : plots) {
Plot myplot=PlotMain.getPlots(world).get(myid);
if ((myplot == null) || !myplot.hasOwner() || !(myplot.getOwner().equals(plr.getUniqueId()))) {
PlayerFunctions.sendMessage(plr,C.NO_PERM_MERGE.s().replaceAll("String_Node_Str",myid.toString()));
return false;
}
}
PlotWorld plotWorld=PlotMain.getWorldSettings(world);
if (PlotMain.useEconomy && plotWorld.USE_ECONOMY) {
double cost=plotWorld.MERGE_PRICE;
cost=plots.size() * cost;
if (cost > 0d) {
Economy economy=PlotMain.economy;
if (economy.getBalance(plr) < cost) {
sendMessage(plr,C.CANNOT_AFFORD_MERGE,cost + "String_Node_Str");
return false;
}
economy.withdrawPlayer(plr,cost);
sendMessage(plr,C.REMOVED_BALANCE,cost + "String_Node_Str");
}
}
PlotMergeEvent event=new PlotMergeEvent(world,plot,plots);
Bukkit.getServer().getPluginManager().callEvent(event);
if (event.isCancelled()) {
event.setCancelled(true);
PlayerFunctions.sendMessage(plr,"String_Node_Str");
return false;
}
PlayerFunctions.sendMessage(plr,"String_Node_Str");
PlotHelper.mergePlots(world,plots);
if (PlotHelper.canSetFast) {
SetBlockFast.update(plr);
}
return true;
}

Fixed version (ground truth):
@Override public boolean execute(Player plr,String... args){
  if (!PlayerFunctions.isInPlot(plr)) {
    PlayerFunctions.sendMessage(plr,C.NOT_IN_PLOT);
    return true;
  }
  Plot plot=PlayerFunctions.getCurrentPlot(plr);
  if ((plot == null) || !plot.hasOwner()) {
    PlayerFunctions.sendMessage(plr,C.NO_PLOT_PERMS);
    return false;
  }
  if (!plot.getOwner().equals(plr.getUniqueId())) {
    PlayerFunctions.sendMessage(plr,C.NO_PLOT_PERMS);
    return false;
  }
  if (args.length < 1) {
    PlayerFunctions.sendMessage(plr,C.SUBCOMMAND_SET_OPTIONS_HEADER.s() + StringUtils.join(values,C.BLOCK_LIST_SEPARATER.s()));
    PlayerFunctions.sendMessage(plr,C.DIRECTION.s().replaceAll("String_Node_Str",direction(plr.getLocation().getYaw())));
    return false;
  }
  int direction=-1;
  for (int i=0; i < values.length; i++) {
    if (args[0].equalsIgnoreCase(values[i]) || args[0].equalsIgnoreCase(aliases[i])) {
      direction=i;
      break;
    }
  }
  if (direction == -1) {
    PlayerFunctions.sendMessage(plr,C.SUBCOMMAND_SET_OPTIONS_HEADER.s() + StringUtils.join(values,C.BLOCK_LIST_SEPARATER.s()));
    PlayerFunctions.sendMessage(plr,C.DIRECTION.s().replaceAll("String_Node_Str",direction(plr.getLocation().getYaw())));
    return false;
  }
  World world=plr.getWorld();
  PlotId bot=PlayerFunctions.getBottomPlot(world,plot).id;
  PlotId top=PlayerFunctions.getTopPlot(world,plot).id;
  ArrayList<PlotId> plots;
switch (direction) {
case 0:
    plots=PlayerFunctions.getMaxPlotSelectionIds(plr.getWorld(),new PlotId(bot.x,bot.y - 1),new PlotId(top.x,top.y));
  break;
case 1:
plots=PlayerFunctions.getMaxPlotSelectionIds(plr.getWorld(),new PlotId(bot.x,bot.y),new PlotId(top.x + 1,top.y));
break;
case 2:
plots=PlayerFunctions.getMaxPlotSelectionIds(plr.getWorld(),new PlotId(bot.x,bot.y),new PlotId(top.x,top.y + 1));
break;
case 3:
plots=PlayerFunctions.getMaxPlotSelectionIds(plr.getWorld(),new PlotId(bot.x - 1,bot.y),new PlotId(top.x,top.y));
break;
default :
return false;
}
for (PlotId myid : plots) {
Plot myplot=PlotMain.getPlots(world).get(myid);
if ((myplot == null) || !myplot.hasOwner() || !(myplot.getOwner().equals(plr.getUniqueId()))) {
PlayerFunctions.sendMessage(plr,C.NO_PERM_MERGE.s().replaceAll("String_Node_Str",myid.toString()));
return false;
}
}
PlotWorld plotWorld=PlotMain.getWorldSettings(world);
if (PlotMain.useEconomy && plotWorld.USE_ECONOMY) {
double cost=plotWorld.MERGE_PRICE;
cost=plots.size() * cost;
if (cost > 0d) {
Economy economy=PlotMain.economy;
if (economy.getBalance(plr) < cost) {
sendMessage(plr,C.CANNOT_AFFORD_MERGE,cost + "String_Node_Str");
return false;
}
economy.withdrawPlayer(plr,cost);
sendMessage(plr,C.REMOVED_BALANCE,cost + "String_Node_Str");
}
}
PlotMergeEvent event=new PlotMergeEvent(world,plot,plots);
Bukkit.getServer().getPluginManager().callEvent(event);
if (event.isCancelled()) {
event.setCancelled(true);
PlayerFunctions.sendMessage(plr,"String_Node_Str");
return false;
}
PlayerFunctions.sendMessage(plr,"String_Node_Str");
PlotHelper.mergePlots(world,plots);
if (PlotHelper.canSetFast) {
SetBlockFast.update(plr);
}
return true;
}