From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Fri, 8 Dec 2023 15:06:16 -0800
Subject: [PATCH] Keep previous behavior for setResourcePack

Before multiple packs were allowed, setResourcePack
resulted in the client's existing server pack being
replaced. To keep this behavior, we will remove all
packs before sending the new pack. Other API exists
for adding a new pack to the existing packs on a client.

diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 558b446cf58f6b66bea23236b24f08f6e281e533..39bf2b92cd8907afa13b9bf7f02553cd2539023b 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -2351,8 +2351,10 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
         if (hash != null) {
             Preconditions.checkArgument(hash.length == 20, "Resource pack hash should be 20 bytes long but was %s", hash.length);
 
+            this.getHandle().connection.send(new net.minecraft.network.protocol.common.ClientboundResourcePackPopPacket(Optional.empty())); // Paper - keep previous behavior of clearing packs
             this.getHandle().connection.send(new ClientboundResourcePackPushPacket(id, url, BaseEncoding.base16().lowerCase().encode(hash), force, CraftChatMessage.fromStringOrNull(prompt, true)));
         } else {
+            this.getHandle().connection.send(new net.minecraft.network.protocol.common.ClientboundResourcePackPopPacket(Optional.empty())); // Paper - keep previous behavior of clearing packs
             this.getHandle().connection.send(new ClientboundResourcePackPushPacket(id, url, "", force, CraftChatMessage.fromStringOrNull(prompt, true)));
         }
     }