From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: chickeneer <emcchickeneer@gmail.com>
Date: Fri, 5 Jun 2020 20:02:04 -0500
Subject: [PATCH] Fix villager trading demand - MC-163962

Prevent demand from going negative and tending to negative infinity

diff --git a/src/main/java/net/minecraft/world/item/trading/MerchantRecipe.java b/src/main/java/net/minecraft/world/item/trading/MerchantRecipe.java
index d840c657a6a992c86364a5f4536da0b217515c53..9e2fe0d5e6d4ea1f4c9cea96b755ddcd1e3c9009 100644
--- a/src/main/java/net/minecraft/world/item/trading/MerchantRecipe.java
+++ b/src/main/java/net/minecraft/world/item/trading/MerchantRecipe.java
@@ -109,7 +109,7 @@ public class MerchantRecipe {
     }
 
     public void e() {
-        this.demand = this.demand + this.uses - (this.maxUses - this.uses);
+        this.demand = Math.max(0, this.demand + this.uses - (this.maxUses - this.uses)); // Paper
     }
 
     public ItemStack f() {