From 3eabe2d2409ef3d178aa5ff6c4768e05552d2844 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sat, 16 Jun 2018 16:23:38 -0400
Subject: [PATCH] Ignore Missing Recipes in RecipeBook to avoid data errors

This code was causing NPE's in saving player data, potentially related to reloads.

diff --git a/src/main/java/net/minecraft/server/RecipeBookServer.java b/src/main/java/net/minecraft/server/RecipeBookServer.java
index 71d6c45529..799f2be707 100644
--- a/src/main/java/net/minecraft/server/RecipeBookServer.java
+++ b/src/main/java/net/minecraft/server/RecipeBookServer.java
@@ -77,7 +77,11 @@ public class RecipeBookServer extends RecipeBook {
         while (iterator.hasNext()) {
             MinecraftKey minecraftkey = (MinecraftKey) iterator.next();
 
-            nbttaglist.add((NBTBase) (new NBTTagString(minecraftkey.toString())));
+            // Paper start - ignore missing recipes
+            IRecipe recipe = this.h.a(minecraftkey);
+            if (recipe == null) continue;
+            nbttaglist.add(new NBTTagString(minecraftkey.toString()));
+            // Paper end
         }
 
         nbttagcompound.set("recipes", nbttaglist);
@@ -87,6 +91,11 @@ public class RecipeBookServer extends RecipeBook {
         while (iterator1.hasNext()) {
             MinecraftKey minecraftkey1 = (MinecraftKey) iterator1.next();
 
+            // Paper start - ignore missing recipes
+            IRecipe recipe = this.h.a(minecraftkey1);
+            if (recipe == null) continue;
+            // Paper end
+
             nbttaglist1.add((NBTBase) (new NBTTagString(minecraftkey1.toString())));
         }
 
-- 
2.18.0