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

--- a/net/minecraft/world/inventory/ContainerFurnace.java
+++ b/net/minecraft/world/inventory/ContainerFurnace.java
@@ -14,6 +14,11 @@
 import net.minecraft.world.level.World;
 import net.minecraft.world.level.block.entity.TileEntityFurnace;
 
+// CraftBukkit start
+import org.bukkit.craftbukkit.inventory.CraftInventoryFurnace;
+import org.bukkit.craftbukkit.inventory.CraftInventoryView;
+// CraftBukkit end
+
 public abstract class ContainerFurnace extends ContainerRecipeBook<SingleRecipeInput, RecipeCooking> {
 
     public static final int INGREDIENT_SLOT = 0;
@@ -31,6 +36,22 @@
     private final Recipes<? extends RecipeCooking> recipeType;
     private final RecipeBookType recipeBookType;
 
+    // CraftBukkit start
+    private CraftInventoryView bukkitEntity = null;
+    private PlayerInventory player;
+
+    @Override
+    public CraftInventoryView getBukkitView() {
+        if (bukkitEntity != null) {
+            return bukkitEntity;
+        }
+
+        CraftInventoryFurnace inventory = new CraftInventoryFurnace((TileEntityFurnace) this.container);
+        bukkitEntity = new CraftInventoryView(this.player.player.getBukkitEntity(), inventory, this);
+        return bukkitEntity;
+    }
+    // CraftBukkit end
+
     protected ContainerFurnace(Containers<?> containers, Recipes<? extends RecipeCooking> recipes, RecipeBookType recipebooktype, int i, PlayerInventory playerinventory) {
         this(containers, recipes, recipebooktype, i, playerinventory, new InventorySubcontainer(3), new ContainerProperties(4));
     }
@@ -47,6 +68,7 @@
         this.addSlot(new Slot(iinventory, 0, 56, 17));
         this.addSlot(new SlotFurnaceFuel(this, iinventory, 1, 56, 53));
         this.addSlot(new SlotFurnaceResult(playerinventory.player, iinventory, 2, 116, 35));
+        this.player = playerinventory; // CraftBukkit - save player
 
         int j;
 
@@ -104,6 +126,7 @@
 
     @Override
     public boolean stillValid(EntityHuman entityhuman) {
+        if (!this.checkReachable) return true; // CraftBukkit
         return this.container.stillValid(entityhuman);
     }