When trying to delete a diamond sword that had Los durability it wouldn't let me delete it. This also seems to affect all tools and armour of every material, trident, shields,shears,flint and steel, bows, and crossbows. The results did not change when they were enchanted. Also when throwing these items into lava to get rid of them they jumped around bore than normal. These items originally had full durability and were not obtained through mob drops, fishing, etc.