Paper/nms-patches/ContainerAnvil.patch

--- a/net/minecraft/server/ContainerAnvil.java
+++ b/net/minecraft/server/ContainerAnvil.java
@@ -6,6 +6,10 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+// CraftBukkit start
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
+// CraftBukkit end
+
 public class ContainerAnvil extends Container {
 
     private static final Logger f = LogManager.getLogger();
@@ -22,8 +26,14 @@
     private int k;
     public String renameText;
     private final EntityHuman m;
+    // CraftBukkit start
+    private int lastLevelCost;
+    private CraftInventoryView bukkitEntity;
+    private PlayerInventory player;
+    // CraftBukkit end
 
     public ContainerAnvil(PlayerInventory playerinventory, final World world, final BlockPosition blockposition, EntityHuman entityhuman) {
+        this.player = playerinventory; // CraftBukkit
         this.j = blockposition;
         this.i = world;
         this.m = entityhuman;
@@ -111,7 +121,7 @@
         byte b1 = 0;
 
         if (itemstack.isEmpty()) {
-            this.g.setItem(0, ItemStack.a);
+            org.bukkit.craftbukkit.event.CraftEventFactory.callPrepareAnvilEvent(getBukkitView(), ItemStack.a); // CraftBukkit
             this.levelCost = 0;
         } else {
             ItemStack itemstack1 = itemstack.cloneItemStack();
@@ -129,7 +139,7 @@
                 if (itemstack1.e() && itemstack1.getItem().a(itemstack, itemstack2)) {
                     k = Math.min(itemstack1.getDamage(), itemstack1.h() / 4);
                     if (k <= 0) {
-                        this.g.setItem(0, ItemStack.a);
+                        org.bukkit.craftbukkit.event.CraftEventFactory.callPrepareAnvilEvent(getBukkitView(), ItemStack.a); // CraftBukkit
                         this.levelCost = 0;
                         return;
                     }
@@ -144,7 +154,7 @@
                     this.k = l;
                 } else {
                     if (!flag && (itemstack1.getItem() != itemstack2.getItem() || !itemstack1.e())) {
-                        this.g.setItem(0, ItemStack.a);
+                        org.bukkit.craftbukkit.event.CraftEventFactory.callPrepareAnvilEvent(getBukkitView(), ItemStack.a); // CraftBukkit
                         this.levelCost = 0;
                         return;
                     }
@@ -237,7 +247,7 @@
                     }
 
                     if (flag2 && !flag1) {
-                        this.g.setItem(0, ItemStack.a);
+                        org.bukkit.craftbukkit.event.CraftEventFactory.callPrepareAnvilEvent(getBukkitView(), ItemStack.a); // CraftBukkit
                         this.levelCost = 0;
                         return;
                     }
@@ -284,7 +294,7 @@
                 EnchantmentManager.a(map, itemstack1);
             }
 
-            this.g.setItem(0, itemstack1);
+            org.bukkit.craftbukkit.event.CraftEventFactory.callPrepareAnvilEvent(getBukkitView(), itemstack1); // CraftBukkit
             this.b();
         }
     }
@@ -302,6 +312,7 @@
     }
 
     public boolean canUse(EntityHuman entityhuman) {
+        if (!this.checkReachable) return true; // CraftBukkit
         return !this.i.getType(this.j).a(TagsBlock.ANVIL) ? false : entityhuman.d((double) this.j.getX() + 0.5D, (double) this.j.getY() + 0.5D, (double) this.j.getZ() + 0.5D) <= 64.0D;
     }
 
@@ -357,4 +368,33 @@
 
         this.d();
     }
+
+    // CraftBukkit start
+    @Override
+    public void b() {
+        super.b();
+
+        for (int i = 0; i < this.listeners.size(); ++i) {
+            ICrafting icrafting = (ICrafting) this.listeners.get(i);
+
+            if (this.lastLevelCost != this.levelCost) {
+                icrafting.setContainerData(this, 0, this.levelCost);
+            }
+        }
+
+        this.lastLevelCost = this.levelCost;
+    }
+
+    @Override
+    public CraftInventoryView getBukkitView() {
+        if (bukkitEntity != null) {
+            return bukkitEntity;
+        }
+
+        org.bukkit.craftbukkit.inventory.CraftInventory inventory = new org.bukkit.craftbukkit.inventory.CraftInventoryAnvil(
+                new org.bukkit.Location(i.getWorld(), j.getX(), j.getY(), j.getZ()), this.h, this.g, this);
+        bukkitEntity = new CraftInventoryView(this.player.player.getBukkitEntity(), inventory, this);
+        return bukkitEntity;
+    }
+    // CraftBukkit end
 }