From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Bjarne Koll <git@lynxplay.dev>
Date: Fri, 1 Nov 2024 14:58:57 +0100
Subject: [PATCH] Correct update cursor

Spigot uses a no longer valid ClientboundContainerSetSlotPacket with the
slot -1, which would update the carried stack in versions <=1.21.1 but
now leads to an IOOB.
1.21.2 instead introduced the ClientboundSetCursorItemPacket, which this
patch uses instead.

diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 68ab52dfdc5599143ce53c930064ef35cd3e2362..2fbe3d8722eeacc3b27ce38145aeffa610f9daab 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -3353,7 +3353,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
                                     case PLACE_SOME:
                                     case PLACE_ONE:
                                     case SWAP_WITH_CURSOR:
-                                        this.player.connection.send(new ClientboundContainerSetSlotPacket(-1, -1, this.player.inventoryMenu.incrementStateId(), this.player.containerMenu.getCarried()));
+                                        this.player.connection.send(new net.minecraft.network.protocol.game.ClientboundSetCursorItemPacket(this.player.containerMenu.getCarried().copy())); // Paper - correctly set cursor
                                         this.player.connection.send(new ClientboundContainerSetSlotPacket(this.player.containerMenu.containerId, this.player.inventoryMenu.incrementStateId(), packet.getSlotNum(), this.player.containerMenu.getSlot(packet.getSlotNum()).getItem()));
                                         break;
                                     // Modified clicked only
@@ -3365,7 +3365,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
                                     case DROP_ALL_CURSOR:
                                     case DROP_ONE_CURSOR:
                                     case CLONE_STACK:
-                                        this.player.connection.send(new ClientboundContainerSetSlotPacket(-1, -1, this.player.inventoryMenu.incrementStateId(), this.player.containerMenu.getCarried()));
+                                        this.player.connection.send(new net.minecraft.network.protocol.game.ClientboundSetCursorItemPacket(this.player.containerMenu.getCarried().copy())); // Paper - correctly set cursor
                                         break;
                                     // Nothing
                                     case NOTHING:
@@ -3543,7 +3543,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
                     // Reset the slot
                     if (packet.slotNum() >= 0) {
                         this.player.connection.send(new ClientboundContainerSetSlotPacket(this.player.inventoryMenu.containerId, this.player.inventoryMenu.incrementStateId(), packet.slotNum(), this.player.inventoryMenu.getSlot(packet.slotNum()).getItem()));
-                        this.player.connection.send(new ClientboundContainerSetSlotPacket(-1, this.player.inventoryMenu.incrementStateId(), -1, ItemStack.EMPTY));
+                        this.player.connection.send(new net.minecraft.network.protocol.game.ClientboundSetCursorItemPacket(ItemStack.EMPTY.copy())); // Paper - correctly set cursor
                     }
                     return;
                 }