Program: 44271
Project: 44271
Buggy source:
public ItemStack nextItemStack(int lootLevel){
  if (material != null) {
    int dropAmount=fixedAmount ? nextFixedAmount() : nextIntAmount(lootLevel);
    if (dropAmount > 0) {
      ItemStack itemStack;
      if (data == null && durability == null) {
        itemStack=new ItemStack(material,dropAmount);
      }
 else {
        MaterialData materialData=data == null ? new MaterialData(material) : new MaterialData(material,data);
        itemStack=materialData.toItemStack(dropAmount);
        if (durability != null) {
          itemStack.setDurability(durability);
        }
      }
      itemStack.addUnsafeEnchantments(EnchantmentChance.nextEnchantments(enchantmentChances));
      if (!attributeChances.isEmpty()) {
        List<Attribute> attributes=AttributeChance.nextAttributes(attributeChances);
        itemStack=Attributes.apply(itemStack,attributes,true);
        ItemMeta meta=itemStack.getItemMeta();
        List<String> lore=new ArrayList<>();
        lore.addAll(meta.getLore());
        for (        Attribute attribute : attributes) {
          Map<MessageToken,String> parameters=new HashMap<>();
          parameters.put(MessageToken.AMOUNT,String.format("String_Node_Str",attribute.getAmount()));
          Message message=AttributeChance.LORE_MAP.get(attribute.getType());
          lore.add(message.assembleMessage(parameters));
        }
        meta.setLore(lore);
      }
      if (unbreakable) {
        itemStack=ItemUtils.setUnbreakable(itemStack);
      }
      if (hideFlags) {
        itemStack=ItemUtils.setHideFlags(itemStack);
      }
      if (itemStack.getAmount() > 0) {
        return itemStack;
      }
    }
  }
  return new ItemStack(Material.AIR,0);
}

Fixed version (ground truth):
public ItemStack nextItemStack(int lootLevel){
  if (material != null) {
    int dropAmount=fixedAmount ? nextFixedAmount() : nextIntAmount(lootLevel);
    if (dropAmount > 0) {
      ItemStack itemStack;
      if (data == null && durability == null) {
        itemStack=new ItemStack(material,dropAmount);
      }
 else {
        MaterialData materialData=data == null ? new MaterialData(material) : new MaterialData(material,data);
        itemStack=materialData.toItemStack(dropAmount);
        if (durability != null) {
          itemStack.setDurability(durability);
        }
      }
      itemStack.addUnsafeEnchantments(EnchantmentChance.nextEnchantments(enchantmentChances));
      if (!attributeChances.isEmpty()) {
        List<Attribute> attributes=AttributeChance.nextAttributes(attributeChances);
        itemStack=Attributes.apply(itemStack,attributes,true);
        List<String> lore=new ArrayList<>();
        for (        Attribute attribute : attributes) {
          Map<MessageToken,String> parameters=new HashMap<>();
          parameters.put(MessageToken.AMOUNT,String.format("String_Node_Str",attribute.getAmount()));
          Message message=AttributeChance.LORE_MAP.get(attribute.getType());
          lore.add(message.assembleMessage(parameters));
        }
        ItemMeta itemMeta=itemStack.getItemMeta();
        itemMeta.setLore(lore);
      }
      if (unbreakable) {
        itemStack=ItemUtils.setUnbreakable(itemStack);
      }
      if (hideFlags) {
        itemStack=ItemUtils.setHideFlags(itemStack);
      }
      if (itemStack.getAmount() > 0) {
        return itemStack;
      }
    }
  }
  return new ItemStack(Material.AIR,0);
}