PaperMC/nms-patches/TileEntityChest.patch

--- a/net/minecraft/server/TileEntityChest.java
+++ b/net/minecraft/server/TileEntityChest.java
@@ -2,6 +2,10 @@
 
 import java.util.Iterator;
 import java.util.List;
+// CraftBukkit start
+import org.bukkit.craftbukkit.entity.CraftHumanEntity;
+import org.bukkit.entity.HumanEntity;
+// CraftBukkit end
 
 public class TileEntityChest extends TileEntityLootable implements ITickable {
 
@@ -11,6 +15,36 @@
     protected int viewingCount;
     private int j;
 
+    // CraftBukkit start - add fields and methods
+    public List<HumanEntity> transaction = new java.util.ArrayList<HumanEntity>();
+    private int maxStack = MAX_STACK;
+
+    public List<ItemStack> getContents() {
+        return this.items;
+    }
+
+    public void onOpen(CraftHumanEntity who) {
+        transaction.add(who);
+    }
+
+    public void onClose(CraftHumanEntity who) {
+        transaction.remove(who);
+    }
+
+    public List<HumanEntity> getViewers() {
+        return transaction;
+    }
+
+    @Override
+    public int getMaxStackSize() {
+        return maxStack;
+    }
+
+    public void setMaxStackSize(int size) {
+        maxStack = size;
+    }
+    // CraftBukkit end
+
     protected TileEntityChest(TileEntityTypes<?> tileentitytypes) {
         super(tileentitytypes);
         this.items = NonNullList.a(27, ItemStack.a);
@@ -155,8 +189,20 @@
             if (this.viewingCount < 0) {
                 this.viewingCount = 0;
             }
+            int oldPower = Math.max(0, Math.min(15, this.viewingCount)); // CraftBukkit - Get power before new viewer is added
 
             ++this.viewingCount;
+            if (this.world == null) return; // CraftBukkit
+
+            // CraftBukkit start - Call redstone event
+            if (this.getBlock().getBlock() == Blocks.TRAPPED_CHEST) {
+                int newPower = Math.max(0, Math.min(15, this.viewingCount));
+
+                if (oldPower != newPower) {
+                    org.bukkit.craftbukkit.event.CraftEventFactory.callRedstoneChange(world, position, oldPower, newPower);
+                }
+            }
+            // CraftBukkit end
             this.onOpen();
         }
 
@@ -165,7 +211,18 @@
     @Override
     public void closeContainer(EntityHuman entityhuman) {
         if (!entityhuman.isSpectator()) {
+            int oldPower = Math.max(0, Math.min(15, this.viewingCount)); // CraftBukkit - Get power before new viewer is added
             --this.viewingCount;
+
+            // CraftBukkit start - Call redstone event
+            if (this.getBlock().getBlock() == Blocks.TRAPPED_CHEST) {
+                int newPower = Math.max(0, Math.min(15, this.viewingCount));
+
+                if (oldPower != newPower) {
+                    org.bukkit.craftbukkit.event.CraftEventFactory.callRedstoneChange(world, position, oldPower, newPower);
+                }
+            }
+            // CraftBukkit end
             this.onOpen();
         }
 
@@ -216,4 +273,11 @@
     protected Container createContainer(int i, PlayerInventory playerinventory) {
         return ContainerChest.a(i, playerinventory, this);
     }
+
+    // CraftBukkit start
+    @Override
+    public boolean isFilteredNBT() {
+        return true;
+    }
+    // CraftBukkit end
 }