From f4a5ccb1f94a49adf172966d8667226389b251e2 Mon Sep 17 00:00:00 2001
From: Camotoy <20743703+Camotoy@users.noreply.github.com>
Date: Sun, 24 Jul 2022 19:41:05 -0400
Subject: [PATCH] Empty villager trades are valid

Fixes #3171
---
 .../protocol/java/inventory/JavaMerchantOffersTranslator.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/inventory/JavaMerchantOffersTranslator.java b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/inventory/JavaMerchantOffersTranslator.java
index 1c9ded0c1..69f00b010 100644
--- a/core/src/main/java/org/geysermc/geyser/translator/protocol/java/inventory/JavaMerchantOffersTranslator.java
+++ b/core/src/main/java/org/geysermc/geyser/translator/protocol/java/inventory/JavaMerchantOffersTranslator.java
@@ -104,7 +104,9 @@ public class JavaMerchantOffersTranslator extends PacketTranslator<ClientboundMe
             recipe.put("sell", getItemTag(session, trade.getOutput()));
 
             // The buy count before demand and special price adjustments
-            recipe.putInt("buyCountA", Math.max(trade.getFirstInput().getAmount(), 0));
+            // The first input CAN be null as of Java 1.19.0/Bedrock 1.19.10
+            // Replicable item: https://gist.github.com/Camotoy/3f3f23d1f80981d1b4472bdb23bba698 from https://github.com/GeyserMC/Geyser/issues/3171
+            recipe.putInt("buyCountA", trade.getFirstInput() != null ? Math.max(trade.getFirstInput().getAmount(), 0) : 0);
             recipe.putInt("buyCountB", trade.getSecondInput() != null ? Math.max(trade.getSecondInput().getAmount(), 0) : 0);
 
             recipe.putInt("demand", trade.getDemand()); // Seems to have no effect