[1.21] Custom ingredients break shapeless crafting

Question

[1.21] Custom ingredients break shapeless crafting

Closed this issue a month ago · 3 comments

Sollace commented a month ago

Shapeless recipes normally ignore empty slots in the crafting grid, but I've found that when you have a custom ingredient in the recipe for which requiresTesting() returns true empty slots become significant when trying to match shapeless recipes.

As a result you can only craft the recipe if all of the recipe's ingredients are lined up one after another in the grid with no gaps.

Eg.
With requiresTesting() == true

With requiresTesting() == false

Ingredient code:

public record ExclusiveIngredient(Ingredient include, Ingredient exclude) implements CustomIngredient {
    public static final MapCodec<ExclusiveIngredient> CODEC = RecordCodecBuilder.mapCodec(i -> i.group(
            Ingredient.DISALLOW_EMPTY_CODEC.fieldOf("include").forGetter(ExclusiveIngredient::include),
            Ingredient.DISALLOW_EMPTY_CODEC.fieldOf("exclude").forGetter(ExclusiveIngredient::exclude)
    ).apply(i, ExclusiveIngredient::new));
    public static final PacketCodec<RegistryByteBuf, ExclusiveIngredient> PACKET_CODEC = PacketCodec.tuple(
            Ingredient.PACKET_CODEC, ExclusiveIngredient::include,
            Ingredient.PACKET_CODEC, ExclusiveIngredient::exclude,
            ExclusiveIngredient::new
    );

    @Override
    public boolean test(ItemStack stack) {
        return include.test(stack) && !exclude.test(stack);
    }

    @Override
    public List<ItemStack> getMatchingStacks() {
        return Arrays.stream(include.getMatchingStacks()).filter(this::test).toList();
    }

    @Override
    public boolean requiresTesting() {
        return false; // change this and restart game to test both cases
    }

    @Override
    public CustomIngredientSerializer<?> getSerializer() {
        return URecipes.EXCLUSIVE_INGREDIENT_SERIALIZER;
    }
}

Recipe json:

{
  "type": "minecraft:crafting_shapeless",
  "category": "misc",
  "group": "bed_sheet_convert",
  "ingredients": [
    {
      "fabric:type": "unicopia:exclusive",
      "exclude": {
        "item": "unicopia:apple_bed_sheets"
      },
      "include": {
        "tag": "unicopia:wool_bed_sheets"
      }
    },
    {
      "item": "minecraft:green_wool"
    },
    {
      "item": "minecraft:lime_wool"
    },
    {
      "item": "minecraft:green_wool"
    },
    {
      "item": "minecraft:lime_wool"
    },
    {
      "item": "minecraft:lime_wool"
    },
    {
      "item": "minecraft:lime_wool"
    },
    {
      "item": "minecraft:green_wool"
    }
  ],
  "result": {
    "count": 2,
    "id": "unicopia:apple_bed_sheets"
  }
}

PepperCode1 · Answer 1 · 2025-09-23T19:16:18.000Z

This was almost certainly fixed by #4287 by its change to ShapelessRecipeMixin. However, that PR targeted 1.21.4 and was not backported. If the same issue affects earlier versions, the fix can be backported.

PepperCode1 · Answer 2 · 2025-09-23T19:22:46.000Z

The regression was introduced in 0af3f5a, which is a 1.21 porting commit, and so this issue affects 1.21-1.21.3. Do you need the fix on specifically 1.21 or is backporting it to only 1.21.1 sufficient?

Sollace · Answer 3 · 2025-09-23T20:41:16.000Z

The regression was introduced in 0af3f5a, which is a 1.21 porting commit, and so this issue affects 1.21-1.21.3. Do you need the fix on specifically 1.21 or is backporting it to only 1.21.1 sufficient?

My builds are technically supporting as far back as 1.21.0 but I believe everyone is using at least 1.21.1 so that will be fine.

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