From 9f81bd0698b9f2060806858c829ddf07f37fbe29 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 7eecdc9da..f65e74ebd 100644
--- a/src/main/java/net/minecraft/server/RecipeBookServer.java
+++ b/src/main/java/net/minecraft/server/RecipeBookServer.java
@@ -63,7 +63,11 @@ public class RecipeBookServer extends RecipeBook {
         while (iterator.hasNext()) {
             IRecipe irecipe = (IRecipe) iterator.next();
 
-            nbttaglist.add(new NBTTagString(((MinecraftKey) CraftingManager.recipes.b(irecipe)).toString()));
+            // Paper start - ignore missing recipes
+            MinecraftKey key = CraftingManager.recipes.b(irecipe);
+            if (key == null) continue;
+            nbttaglist.add(new NBTTagString(key.toString()));
+            // Paper end
         }
 
         nbttagcompound.set("recipes", nbttaglist);
@@ -71,9 +75,13 @@ public class RecipeBookServer extends RecipeBook {
         Iterator iterator1 = this.e().iterator();
 
         while (iterator1.hasNext()) {
-            IRecipe irecipe1 = (IRecipe) iterator1.next();
+            // Paper start - ignore missing recipes
+            IRecipe irecipe = (IRecipe) iterator1.next();
 
-            nbttaglist1.add(new NBTTagString(((MinecraftKey) CraftingManager.recipes.b(irecipe1)).toString()));
+            MinecraftKey key = CraftingManager.recipes.b(irecipe);
+            if (key == null) continue;
+            nbttaglist1.add(new NBTTagString(key.toString()));
+            // Paper end
         }
 
         nbttagcompound.set("toBeDisplayed", nbttaglist1);
-- 
2.18.0