Paper/patches/server/0568-MC-4-Fix-item-position-desync.patch
Nassim Jahnke 789bc79280
Updated Upstream (Bukkit/CraftBukkit/Spigot) (#6457)
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:
c9a46ebf #653: Add World#spawn with randomizeData parameter
e49c2e3a Damageable should extend ItemMeta
01ff04f4 SPIGOT-5880, SPIGOT-5567: New ChunkGenerator API
ca5b4b1a SPIGOT-6697: Deprecate generateTree with BlockChangeDelegate as it does not handle tiles

CraftBukkit Changes:
7c8bbcbe SPIGOT-6716: Preserve the order of stored enchantments of enchanted books.
18027d02 #914: Add World#spawn with randomizeData parameter
3cad0316 SPIGOT-6714: Don't fire PlayerBucketEvent when empty
8c6d60cf Fix server crash with BlockPopulator when entities are at a negative chunk border
4f6bcc84 SPIGOT-5880, SPIGOT-5567: New ChunkGenerator API
78d5b35b SPIGOT-6697: Restore generateTree with BlockChangeDelegate behaviour
15792f0d Rebuild patch
c949675e SPIGOT-6713: Cancelling EntityTransformEvent Causes Deceased Slimes To Not Despawn
a955f15c Fix issues with new ChunkGenerator API
a0a37f41 SPIGOT-6630: Replacing an enchantment on an item creates a conflict error

Spigot Changes:
b166a49b Rebuild patches
3c1fc60a SPIGOT-6693: Composters only take in one item at custom hopper speeds
2021-08-25 09:59:26 +02:00

64 lines
3.4 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: BillyGalbreath <blake.galbreath@gmail.com>
Date: Tue, 8 Dec 2020 20:24:52 -0600
Subject: [PATCH] MC-4: Fix item position desync
This fixes item position desync (MC-4) by running the item coordinates
through the encode/decode methods of the packet that causes the precision
loss, which forces the server to lose the same precision as the client
keeping them in sync.
diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
index ec8afe1bb9881c87c4ee0f15dcfcb4b8f318febc..e6ce1f9f065a2e6293a651922273a6034df19d0f 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -492,4 +492,9 @@ public class PaperConfig {
private static void trackPluginScoreboards() {
trackPluginScoreboards = getBoolean("settings.track-plugin-scoreboards", false);
}
+
+ public static boolean fixEntityPositionDesync = true;
+ private static void fixEntityPositionDesync() {
+ fixEntityPositionDesync = getBoolean("settings.fix-entity-position-desync", fixEntityPositionDesync);
+ }
}
diff --git a/src/main/java/net/minecraft/network/protocol/game/ClientboundMoveEntityPacket.java b/src/main/java/net/minecraft/network/protocol/game/ClientboundMoveEntityPacket.java
index b30c08bfb8c55161543a4ef09f2e462e0a1fe4ae..ec93f5300cc7d423ec0d292f0f8443f900d72dab 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundMoveEntityPacket.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundMoveEntityPacket.java
@@ -21,11 +21,11 @@ public abstract class ClientboundMoveEntityPacket implements Packet<ClientGamePa
protected final boolean hasPos;
public static long entityToPacket(double coord) {
- return Mth.lfloor(coord * 4096.0D);
+ return Mth.lfloor(coord * 4096.0D); // Paper - check ItemEntity#setPosRaw on update
}
public static double packetToEntity(long coord) {
- return (double)coord / 4096.0D;
+ return (double)coord / 4096.0D; // Paper - check ItemEntity#setPosRaw on update
}
public Vec3 updateEntityPosition(Vec3 orig) {
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 5ff6afc2a5fbf9f2bec34621d63a400e2acc1d63..f0ca8889d9e020dd0c20ff35acadeeac35a0957e 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -3762,6 +3762,16 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
}
public final void setPosRaw(double x, double y, double z, boolean forceBoundingBoxUpdate) {
// Paper end
+ // Paper start - fix MC-4
+ if (this instanceof ItemEntity) {
+ if (com.destroystokyo.paper.PaperConfig.fixEntityPositionDesync) {
+ // encode/decode from PacketPlayOutEntity
+ x = Mth.lfloor(x * 4096.0D) * (1 / 4096.0D);
+ y = Mth.lfloor(y * 4096.0D) * (1 / 4096.0D);
+ z = Mth.lfloor(z * 4096.0D) * (1 / 4096.0D);
+ }
+ }
+ // Paper end - fix MC-4
if (this.position.x != x || this.position.y != y || this.position.z != z) {
this.position = new Vec3(x, y, z);
int i = Mth.floor(x);