ShapelessRecipes.java

            // Paper start
            java.util.List<ItemStack> providedItems = new java.util.ArrayList<>();
            co.aikar.util.Counter<ItemStack> matchedProvided = new co.aikar.util.Counter<>();
            co.aikar.util.Counter<RecipeItemStack> matchedIngredients = new co.aikar.util.Counter<>();
            // Paper end
            for (int j = 0; j < iinventory.n(); ++j) {
                for (int k = 0; k < iinventory.U_(); ++k) {
                    ItemStack itemstack = iinventory.getItem(k + j * iinventory.U_());

                    if (!itemstack.isEmpty()) {
                        // Paper start
                        itemstack = itemstack.cloneItemStack();
                        providedItems.add(itemstack);
                        for (RecipeItemStack ingredient : ingredients) {
                            if (ingredient.test(itemstack)) {
                                matchedProvided.increment(itemstack);
                                matchedIngredients.increment(ingredient);
                            }
                        }
                        // Paper end
                    }
                }
            }
            // Paper start
            java.util.List<RecipeItemStack> ingredients = new java.util.ArrayList<>(this.ingredients);
            providedItems.sort(java.util.Comparator.comparingInt((ItemStack c) -> (int) matchedProvided.getCount(c)).reversed());
            ingredients.sort(java.util.Comparator.comparingInt((RecipeItemStack c) -> (int) matchedIngredients.getCount(c)));

            PROVIDED:
            for (ItemStack provided : providedItems) {
                for (Iterator<RecipeItemStack> itIngredient = ingredients.iterator(); itIngredient.hasNext(); ) {
                    RecipeItemStack ingredient = itIngredient.next();
                    if (ingredient.test(provided)) {
                        itIngredient.remove();
                        continue PROVIDED;
                    }
                }
                return false;
            }
            return ingredients.isEmpty();
            // Paper end