Advancement trigger item_durability_changed doesn't trigger with mending

Still in 18w50a; but the xp_orb needs changing to experience_orb

Confirmed in 20w22a.

Confirmed in 1.17.1.

Can confirm in 21w37a. I've created and attached a data pack to make reproducing this issue much easier. Here are some additional details regarding this problem.

The Bug:

The minecraft:item_durability_changed advancement trigger doesn't trigger when the mending enchantment repairs items.

Steps to Reproduce:

• Download the attached data pack.

• Create a new world using this data pack.

• Once you've entered the world, reload all data packs.

/reload

• Give yourself a wooden shovel enchanted with mending that is slightly damaged.

/give @s minecraft:wooden_shovel{Damage:30,Enchantments:[{id:"mending",lvl:1}]}

• Switch into survival mode and use the shovel.

• → ✔  Notice how the scoreboard increases, therefore indicating that the minecraft:item_durability_changed advancement trigger was triggered.

• Make sure you're holding the shovel and summon an experience orb at your position so that the mending enchantment repairs it.

/summon minecraft:experience_orb ~ ~ ~ {Value:1}

• → ❌  Notice how the scoreboard doesn't increase, therefore indicating that the minecraft:item_durability_changed advancement trigger doesn't trigger when the mending enchantment repairs items.

Expected Behavior:

The expected behavior would be that the minecraft:item_durability_changed advancement trigger would trigger when the mending enchantment repairs items.

Here's a code analysis of this issue along with a potential fix regarding this issue.

Code Analysis:

The following is based on a decompiled version of Minecraft 1.18.1 using MCP-Reborn.

net.minecraft.world.entity.ExperienceOrb.java

public class ExperienceOrb extends Entity {
   ...
   private int repairPlayerItems(Player $p, int $i) {
      Entry<EquipmentSlot, ItemStack> entry = EnchantmentHelper.getRandomItemWith(Enchantments.MENDING, $p, ItemStack::isDamaged);
      if (entry != null) {
         ItemStack itemstack = entry.getValue();
         int i = Math.min(this.xpToDurability(this.value), itemstack.getDamageValue());
         itemstack.setDamageValue(itemstack.getDamageValue() - i);
         int j = $i - this.durabilityToXp(i);
         return j > 0 ? this.repairPlayerItems($p, j) : 0;
      } else {
         return $i;
      }
   }
   ...

If we look at the above class, we can see that when experience orbs repair the player's items, the ITEM_DURABILITY_CHANGED criteria trigger, is never triggered.

Potential Fix:

Simply adding a line of code in the appropriate place that triggers the ITEM_DURABILITY_CHANGED advancement trigger, should resolve this problem. The following line of code could be used in order to fix this:

CriteriaTriggers.ITEM_DURABILITY_CHANGED.trigger(...)

can confirm in 1.19.2

That's already marked as affected. 😉