From ac2823f4090e996ccafb904bad20fb010ea2c081 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 26 Jul 2017 21:12:15 -0400
Subject: [PATCH] Fix Recipe Books


diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
index 682211cdd..0b0a34508 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -2027,12 +2027,6 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
     public void a(PacketPlayInAutoRecipe packetplayinautorecipe) {
         PlayerConnectionUtils.ensureMainThread(packetplayinautorecipe, this, this.player.x());
         this.player.resetIdleTimer();
-        // CraftBukkit start
-        if (!player.getBukkitEntity().hasPermission("minecraft.autocraft")) {
-            player.getBukkitEntity().updateInventory();
-            return;
-        }
-        // CraftBukkit end
         if (this.player.activeContainer.windowId == packetplayinautorecipe.a() && this.player.activeContainer.c(this.player)) {
             this.player.playerConnection.sendPacket(new PacketPlayOutTransaction(packetplayinautorecipe.a(), packetplayinautorecipe.b(), true));
             Iterator iterator;
@@ -2046,7 +2040,10 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
                 while (iterator.hasNext()) {
                     packetplayinautorecipe_a = (PacketPlayInAutoRecipe.a) iterator.next();
                     itemstack = this.player.activeContainer.getSlot(packetplayinautorecipe_a.b).getItem();
-                    if (this.a(packetplayinautorecipe_a.a, itemstack)) {
+                    // Paper start - improve validation
+                    ItemStack to = this.player.activeContainer.getSlot(packetplayinautorecipe_a.c).getItem();
+                    if (this.a(packetplayinautorecipe_a.a, itemstack) && (to.isEmpty() || this.a(packetplayinautorecipe_a.a, to))) {
+                        // Paper end
                         i = packetplayinautorecipe_a.a.getCount();
                         if (packetplayinautorecipe_a.c == -1) {
                             this.player.drop(packetplayinautorecipe_a.a, true);
@@ -2066,6 +2063,12 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
                             itemstack.subtract(i);
                         }
                     }
+                    // Paper start
+                    else {
+                        this.player.getBukkitEntity().updateInventory();
+                        return;
+                    }
+                    // Paper end
                 }
             }
 
-- 
2.13.0