From 5b7474984ba8737f465a04c12a30319613de4536 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Sun, 27 Dec 2020 11:31:06 +0000
Subject: [PATCH] Fix crash from invalid ingredient lists in
 VillagerAcquireTradeEvent

---
 .../world/entity/npc/AbstractVillager.java.patch          | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/paper-server/patches/sources/net/minecraft/world/entity/npc/AbstractVillager.java.patch b/paper-server/patches/sources/net/minecraft/world/entity/npc/AbstractVillager.java.patch
index 2ee4a021d8..37321c76f6 100644
--- a/paper-server/patches/sources/net/minecraft/world/entity/npc/AbstractVillager.java.patch
+++ b/paper-server/patches/sources/net/minecraft/world/entity/npc/AbstractVillager.java.patch
@@ -54,7 +54,7 @@
              Logger logger = AbstractVillager.LOGGER;
  
              Objects.requireNonNull(logger);
-@@ -246,7 +266,16 @@
+@@ -246,7 +266,20 @@
              MerchantOffer merchantrecipe = ((VillagerTrades.ItemListing) arraylist.remove(this.random.nextInt(arraylist.size()))).getOffer(this, this.random);
  
              if (merchantrecipe != null) {
@@ -66,7 +66,11 @@
 +                    Bukkit.getPluginManager().callEvent(event);
 +                }
 +                if (!event.isCancelled()) {
-+                    recipeList.add(CraftMerchantRecipe.fromBukkit(event.getRecipe()).toMinecraft());
++                    // Paper start - Fix crash from invalid ingredient list
++                    final CraftMerchantRecipe craftMerchantRecipe = CraftMerchantRecipe.fromBukkit(event.getRecipe());
++                    if (craftMerchantRecipe.getIngredients().isEmpty()) return;
++                    recipeList.add(craftMerchantRecipe.toMinecraft());
++                    // Paper end - Fix crash from invalid ingredient list
 +                }
 +                // CraftBukkit end
                  ++j;