[Bug] Non-existing enchantment books popping up in villager trading

[basileus956]

Is there an existing issue for this?

• I have searched the existing issues

Observed behaviour

I'm getting trades for books that don't even exist in creative mode (these enchantments are magical in nature and I think they're supposed to be temporary, so stuff like Frost Imbuement)

These items get unenchant immediatley after applying those enchants in the anvil or via /enchant

Expected behaviour

That these books either get added to creative mode or removed from the trades menu entirely.

Steps to reproduce

1. Find a librarian that sells these books, might be difficult to reproduce..
2. Yeah.. you will find a librarian that has these books eventually

Crashlog

No response

Environment (Singleplayer/Server, etc.)

Singleplayer

Mod version

4.3.14

Minecraft version

1.12.2

Forge version

14.23.5.2860

Other mods

[Nischhelm]

had that happen too. the used safetynets against being visible in jei/creative inventory is setting EnumEnchantmentType to null and setting canApply/canApplyAtETable/isAllowedOnBooks to false, which makes the enchantment not go on any item by default unless forced.

But isAllowedOnBooks is only checked for leveled application of enchantments to items ("enchant_with_levels" and enchanting via enchanting table, both going through EnchantmentHelper.buildEnchantmentList).

so this boolean is NOT used for villagers and enchant_randomly. also not used for modded sources like infernalmobs dropping random enchants just pulled from the registry.

in my modpack i use (my own mod) EnchantmentControl to just blacklist the enchantments from those sources. doing so is not possible without mixins.