PaperMC/paper-server/nms-patches/net/minecraft/world/inventory/ContainerBeacon.patch

--- a/net/minecraft/world/inventory/ContainerBeacon.java
+++ b/net/minecraft/world/inventory/ContainerBeacon.java
@@ -12,6 +12,11 @@
 import net.minecraft.world.level.World;
 import net.minecraft.world.level.block.Blocks;
 
+// CraftBukkit start
+import net.minecraft.world.entity.player.PlayerInventory;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
+// CraftBukkit end
+
 public class ContainerBeacon extends Container {
 
     private static final int PAYMENT_SLOT = 0;
@@ -26,6 +31,10 @@
     private final ContainerBeacon.SlotBeacon paymentSlot;
     private final ContainerAccess access;
     private final IContainerProperties beaconData;
+    // CraftBukkit start
+    private CraftInventoryView bukkitEntity = null;
+    private PlayerInventory player;
+    // CraftBukkit end
 
     public ContainerBeacon(int i, IInventory iinventory) {
         this(i, iinventory, new ContainerProperties(3), ContainerAccess.NULL);
@@ -33,6 +42,7 @@
 
     public ContainerBeacon(int i, IInventory iinventory, IContainerProperties icontainerproperties, ContainerAccess containeraccess) {
         super(Containers.BEACON, i);
+        player = (PlayerInventory) iinventory; // CraftBukkit - TODO: check this
         this.beacon = new InventorySubcontainer(1) {
             @Override
             public boolean canPlaceItem(int j, ItemStack itemstack) {
@@ -82,6 +92,7 @@
 
     @Override
     public boolean stillValid(EntityHuman entityhuman) {
+        if (!this.checkReachable) return true; // CraftBukkit
         return stillValid(this.access, entityhuman, Blocks.BEACON);
     }
 
@@ -163,8 +174,8 @@
 
     public void updateEffects(Optional<MobEffectList> optional, Optional<MobEffectList> optional1) {
         if (this.paymentSlot.hasItem()) {
-            this.beaconData.set(1, encodeEffect((MobEffectList) optional.orElse((Object) null)));
-            this.beaconData.set(2, encodeEffect((MobEffectList) optional1.orElse((Object) null)));
+            this.beaconData.set(1, encodeEffect((MobEffectList) optional.orElse(null))); // CraftBukkit - decompile error
+            this.beaconData.set(2, encodeEffect((MobEffectList) optional1.orElse(null))); // CraftBukkit - decompile error
             this.paymentSlot.remove(1);
             this.access.execute(World::blockEntityChanged);
         }
@@ -191,4 +202,17 @@
             return 1;
         }
     }
+
+    // CraftBukkit start
+    @Override
+    public CraftInventoryView getBukkitView() {
+        if (bukkitEntity != null) {
+            return bukkitEntity;
+        }
+
+        org.bukkit.craftbukkit.inventory.CraftInventory inventory = new org.bukkit.craftbukkit.inventory.CraftInventoryBeacon(this.beacon);
+        bukkitEntity = new CraftInventoryView(this.player.player.getBukkitEntity(), inventory, this);
+        return bukkitEntity;
+    }
+    // CraftBukkit end
 }