Program: 51662
Project: 51662
Buggy source:
@Override public void simpleMode(InventoryClickEvent event){
  Player p=(Player)event.getWhoClicked();
  DecimalFormat f=new DecimalFormat("String_Node_Str");
  int slot=event.getSlot();
  boolean top=event.getView().convertSlot(event.getRawSlot()) == event.getRawSlot();
  if (top) {
    if (isManagementSlot(slot,1)) {
      if (isWool(event.getCurrentItem(),config.getItemManagement(7))) {
        switchInventory(TraderStatus.SELL);
      }
 else       if (isWool(event.getCurrentItem(),config.getItemManagement(0))) {
        switchInventory(TraderStatus.SELL);
      }
 else       if (isWool(event.getCurrentItem(),config.getItemManagement(1))) {
        switchInventory(TraderStatus.BUY);
      }
    }
 else     if (equalsTraderStatus(TraderStatus.SELL)) {
      if (selectItem(slot,TraderStatus.SELL).hasSelectedItem()) {
        if (getSelectedItem().hasMultipleAmouts()) {
          switchInventory(getSelectedItem());
          setTraderStatus(TraderStatus.SELL_AMOUNT);
        }
 else {
          if (getClickedSlot() == slot) {
            if (checkLimits(p) && inventoryHasPlace(p,0) && buyTransaction(p,getSelectedItem().getPrice())) {
              p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str" + getSelectedItem().getAmount()).replace("String_Node_Str",f.format(getSelectedItem().getPrice())));
              addSelectedToInventory(p,0);
              updateLimits(p.getName());
              log("String_Node_Str",p.getName(),getSelectedItem().getItemStack().getTypeId(),getSelectedItem().getItemStack().getData().getData(),getSelectedItem().getAmount(),getSelectedItem().getPrice());
            }
 else             p.sendMessage(locale.getMessage("String_Node_Str"));
          }
 else {
            p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice())));
            p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str"));
            setClickedSlot(slot);
          }
        }
      }
    }
 else     if (equalsTraderStatus(TraderStatus.SELL_AMOUNT)) {
      if (!event.getCurrentItem().getType().equals(Material.AIR)) {
        if (getClickedSlot() == slot) {
          if (checkLimits(p,slot) && inventoryHasPlace(p,slot) && buyTransaction(p,getSelectedItem().getPrice(slot))) {
            p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str" + getSelectedItem().getAmount(slot)).replace("String_Node_Str",f.format(getSelectedItem().getPrice(slot))));
            addSelectedToInventory(p,slot);
            updateLimits(p.getName(),slot);
            log("String_Node_Str",p.getName(),getSelectedItem().getItemStack().getTypeId(),getSelectedItem().getItemStack().getData().getData(),getSelectedItem().getAmount(slot),getSelectedItem().getPrice(slot));
          }
 else           p.sendMessage(locale.getMessage("String_Node_Str"));
        }
 else {
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice(slot))));
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str"));
          setClickedSlot(slot);
        }
      }
    }
 else     if (equalsTraderStatus(TraderStatus.BUY)) {
      if (selectItem(slot,TraderStatus.BUY).hasSelectedItem()) {
        p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice())));
      }
    }
    setInventoryClicked(true);
  }
 else {
    if (equalsTraderStatus(TraderStatus.BUY)) {
      if (selectItem(event.getCurrentItem(),TraderStatus.BUY,true,true).hasSelectedItem()) {
        if (getClickedSlot() == slot && !getInventoryClicked()) {
          int scale=event.getCurrentItem().getAmount() / getSelectedItem().getAmount();
          if (checkBuyLimits(p,scale) && sellTransaction(p,getSelectedItem().getPrice(),event.getCurrentItem())) {
            p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str" + getSelectedItem().getAmount() * scale).replace("String_Node_Str",f.format(getSelectedItem().getPrice() * scale)));
            updateBuyLimits(p.getName(),scale);
            removeFromInventory(event.getCurrentItem(),event);
            log("String_Node_Str",p.getName(),getSelectedItem().getItemStack().getTypeId(),getSelectedItem().getItemStack().getData().getData(),getSelectedItem().getAmount() * scale,getSelectedItem().getPrice() * scale);
          }
 else           p.sendMessage(locale.getMessage("String_Node_Str"));
        }
 else {
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice() * ((int)event.getCurrentItem().getAmount() / getSelectedItem().getAmount()))));
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str"));
          setClickedSlot(slot);
        }
      }
    }
 else     if (equalsTraderStatus(TraderStatus.SELL_AMOUNT)) {
      p.sendMessage(locale.getMessage("String_Node_Str"));
      event.setCancelled(true);
      return;
    }
 else     if (selectItem(event.getCurrentItem(),TraderStatus.BUY,true,true).hasSelectedItem()) {
      if (getClickedSlot() == slot && !getInventoryClicked()) {
        int scale=event.getCurrentItem().getAmount() / getSelectedItem().getAmount();
        if (checkBuyLimits(p,scale) && sellTransaction(p,getSelectedItem().getPrice(),event.getCurrentItem())) {
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str" + getSelectedItem().getAmount() * scale).replace("String_Node_Str",f.format(getSelectedItem().getPrice() * scale)));
          updateBuyLimits(p.getName(),scale);
          removeFromInventory(event.getCurrentItem(),event);
          log("String_Node_Str",p.getName(),getSelectedItem().getItemStack().getTypeId(),getSelectedItem().getItemStack().getData().getData(),getSelectedItem().getAmount() * scale,getSelectedItem().getPrice() * scale);
        }
 else         p.sendMessage(locale.getMessage("String_Node_Str"));
      }
 else {
        if (!event.getCurrentItem().equals(new ItemStack(Material.WOOL,1,(short)0,(byte)3)) && !event.getCurrentItem().getType().equals(Material.AIR)) {
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice() * ((int)event.getCurrentItem().getAmount() / getSelectedItem().getAmount()))));
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str"));
          setClickedSlot(slot);
        }
      }
    }
    setInventoryClicked(false);
  }
  event.setCancelled(true);
}

Fixed version (ground truth):
@Override public void simpleMode(InventoryClickEvent event){
  Player p=(Player)event.getWhoClicked();
  DecimalFormat f=new DecimalFormat("String_Node_Str");
  int slot=event.getSlot();
  boolean top=event.getView().convertSlot(event.getRawSlot()) == event.getRawSlot();
  if (top) {
    if (isManagementSlot(slot,1)) {
      if (isWool(event.getCurrentItem(),config.getItemManagement(7))) {
        switchInventory(TraderStatus.SELL);
      }
 else       if (isWool(event.getCurrentItem(),config.getItemManagement(0))) {
        switchInventory(TraderStatus.SELL);
      }
 else       if (isWool(event.getCurrentItem(),config.getItemManagement(1))) {
        switchInventory(TraderStatus.BUY);
      }
    }
 else     if (equalsTraderStatus(TraderStatus.SELL)) {
      if (selectItem(slot,TraderStatus.SELL).hasSelectedItem()) {
        if (getSelectedItem().hasMultipleAmouts()) {
          switchInventory(getSelectedItem());
          setTraderStatus(TraderStatus.SELL_AMOUNT);
        }
 else {
          if (getClickedSlot() == slot) {
            if (checkLimits(p) && inventoryHasPlace(p,0) && buyTransaction(p,getSelectedItem().getPrice())) {
              p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str" + getSelectedItem().getAmount()).replace("String_Node_Str",f.format(getSelectedItem().getPrice())));
              addSelectedToInventory(p,0);
              updateLimits(p.getName());
              log("String_Node_Str",p.getName(),getSelectedItem().getItemStack().getTypeId(),getSelectedItem().getItemStack().getData().getData(),getSelectedItem().getAmount(),getSelectedItem().getPrice());
            }
 else             p.sendMessage(locale.getMessage("String_Node_Str"));
          }
 else {
            p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice())));
            p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str"));
            setClickedSlot(slot);
          }
        }
      }
    }
 else     if (equalsTraderStatus(TraderStatus.SELL_AMOUNT)) {
      if (!event.getCurrentItem().getType().equals(Material.AIR)) {
        if (getClickedSlot() == slot) {
          if (checkLimits(p,slot) && inventoryHasPlace(p,slot) && buyTransaction(p,getSelectedItem().getPrice(slot))) {
            p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str" + getSelectedItem().getAmount(slot)).replace("String_Node_Str",f.format(getSelectedItem().getPrice(slot))));
            addSelectedToInventory(p,slot);
            updateLimits(p.getName(),slot);
            switchInventory(getSelectedItem());
            log("String_Node_Str",p.getName(),getSelectedItem().getItemStack().getTypeId(),getSelectedItem().getItemStack().getData().getData(),getSelectedItem().getAmount(slot),getSelectedItem().getPrice(slot));
          }
 else           p.sendMessage(locale.getMessage("String_Node_Str"));
        }
 else {
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice(slot))));
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str"));
          setClickedSlot(slot);
        }
      }
    }
 else     if (equalsTraderStatus(TraderStatus.BUY)) {
      if (selectItem(slot,TraderStatus.BUY).hasSelectedItem()) {
        p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice())));
      }
    }
    setInventoryClicked(true);
  }
 else {
    if (equalsTraderStatus(TraderStatus.BUY)) {
      if (selectItem(event.getCurrentItem(),TraderStatus.BUY,true,true).hasSelectedItem()) {
        if (getClickedSlot() == slot && !getInventoryClicked()) {
          int scale=event.getCurrentItem().getAmount() / getSelectedItem().getAmount();
          if (checkBuyLimits(p,scale) && sellTransaction(p,getSelectedItem().getPrice(),event.getCurrentItem())) {
            p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str" + getSelectedItem().getAmount() * scale).replace("String_Node_Str",f.format(getSelectedItem().getPrice() * scale)));
            updateBuyLimits(p.getName(),scale);
            removeFromInventory(event.getCurrentItem(),event);
            log("String_Node_Str",p.getName(),getSelectedItem().getItemStack().getTypeId(),getSelectedItem().getItemStack().getData().getData(),getSelectedItem().getAmount() * scale,getSelectedItem().getPrice() * scale);
          }
 else           p.sendMessage(locale.getMessage("String_Node_Str"));
        }
 else {
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice() * ((int)event.getCurrentItem().getAmount() / getSelectedItem().getAmount()))));
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str"));
          setClickedSlot(slot);
        }
      }
    }
 else     if (equalsTraderStatus(TraderStatus.SELL_AMOUNT)) {
      p.sendMessage(locale.getMessage("String_Node_Str"));
      event.setCancelled(true);
      return;
    }
 else     if (selectItem(event.getCurrentItem(),TraderStatus.BUY,true,true).hasSelectedItem()) {
      if (getClickedSlot() == slot && !getInventoryClicked()) {
        int scale=event.getCurrentItem().getAmount() / getSelectedItem().getAmount();
        if (checkBuyLimits(p,scale) && sellTransaction(p,getSelectedItem().getPrice(),event.getCurrentItem())) {
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str" + getSelectedItem().getAmount() * scale).replace("String_Node_Str",f.format(getSelectedItem().getPrice() * scale)));
          updateBuyLimits(p.getName(),scale);
          removeFromInventory(event.getCurrentItem(),event);
          log("String_Node_Str",p.getName(),getSelectedItem().getItemStack().getTypeId(),getSelectedItem().getItemStack().getData().getData(),getSelectedItem().getAmount() * scale,getSelectedItem().getPrice() * scale);
        }
 else         p.sendMessage(locale.getMessage("String_Node_Str"));
      }
 else {
        if (!event.getCurrentItem().equals(new ItemStack(Material.WOOL,1,(short)0,(byte)3)) && !event.getCurrentItem().getType().equals(Material.AIR)) {
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str",f.format(getSelectedItem().getPrice() * ((int)event.getCurrentItem().getAmount() / getSelectedItem().getAmount()))));
          p.sendMessage(locale.getMessage("String_Node_Str").replace("String_Node_Str","String_Node_Str"));
          setClickedSlot(slot);
        }
      }
    }
    setInventoryClicked(false);
  }
  event.setCancelled(true);
}