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. mc-127340.zip
• 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.

Code analysis and fix

Code analysis and fix by Avoma can be found in this comment.