PaperMC/patches/server/0439-Prevent-position-desync-in-playerconnection-causing-.patch
Jake Potrebic 1c5f8b0fce
Updated Upstream (Bukkit/CraftBukkit) (#7604)
Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
33a2b476 PR-734: Make PlayerInventory#getItem Nullable

CraftBukkit Changes:
953d3ddc SPIGOT-3034: PlayerKickEvent.setLeaveMessage(String) doesn't actually do anything
2c47af0c SPIGOT-6963: CraftMetaBlockState#getBlockState applied TileEntity ids without the minecraft namespace prefix.
2022-03-16 16:57:51 +01:00

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Fri, 12 Jun 2020 16:51:39 -0700
Subject: [PATCH] Prevent position desync in playerconnection causing tp
exploit
Caused the server to revert to the player's overworld coordinates
after teleporting into the end.
Sidenote: The underlying issue is that the move call can teleport
entities and do other things like kill the entity. In the future,
to fix all exploits derieved from this usually unexpected
behaviour, we need to move all of this dangerous logic outside
of the move call and into an appropriate place in the tick method.
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index f1be2494f254b1d5fc5c602bb6674829a86751b9..a0597bf8d948f20becd7ccb748a78f8a14a54cf6 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -1342,6 +1342,11 @@ public class ServerGamePacketListenerImpl implements ServerPlayerConnection, Ser
this.player.move(MoverType.PLAYER, new Vec3(d7, d8, d9));
this.player.onGround = packet.isOnGround(); // CraftBukkit - SPIGOT-5810, SPIGOT-5835, SPIGOT-6828: reset by this.player.move
+ // Paper start - prevent position desync
+ if (this.awaitingPositionFromClient != null) {
+ return; // ... thanks Mojang for letting move calls teleport across dimensions.
+ }
+ // Paper end - prevent position desync
double d12 = d8;
d7 = d0 - this.player.getX();