From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: chickeneer <emcchickeneer@gmail.com>
Date: Tue, 16 Feb 2021 21:37:51 -0600
Subject: [PATCH] Prevent grindstones from overstacking items


diff --git a/src/main/java/net/minecraft/server/ContainerGrindstone.java b/src/main/java/net/minecraft/server/ContainerGrindstone.java
index 57b3c42b6b3fcf791591897fa12d12c2c396191c..99e342038172d7e74a45789bd4b58d4660c775d3 100644
--- a/src/main/java/net/minecraft/server/ContainerGrindstone.java
+++ b/src/main/java/net/minecraft/server/ContainerGrindstone.java
@@ -184,13 +184,13 @@ public class ContainerGrindstone extends Container {
                 i = Math.max(item.getMaxDurability() - l, 0);
                 itemstack2 = this.b(itemstack, itemstack1);
                 if (!itemstack2.e()) {
-                    if (!ItemStack.matches(itemstack, itemstack1)) {
+                    if (!ItemStack.matches(itemstack, itemstack1) || itemstack2.getMaxStackSize() == 1) { // Paper - add max stack size check
                         this.resultInventory.setItem(0, ItemStack.b);
                         this.c();
                         return;
                     }
 
-                    b0 = 2;
+                    b0 = 2; // Paper - the problem line for above change, causing over-stacking
                 }
             } else {
                 boolean flag3 = !itemstack.isEmpty();