Paper/patches/server/0540-MC-4-Fix-item-position-desync.patch
Jake 00be0b7b30 Updated Upstream (Bukkit/CraftBukkit/Spigot)
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:
d25437bc Update to Minecraft 1.18-pre8

CraftBukkit Changes:
5a39a236 Update to Minecraft 1.18-pre8

Spigot Changes:
7840c2af Update to Minecraft 1.18-pre8
2021-11-30 19:26:33 +01:00

66 lines
3.6 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 1de3d8848419fce792e28c8100eca1b2488ac968..408e359e6f1a07c5616822e2ecf7549bf481c77d 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -101,6 +101,11 @@ public class PaperConfig {
trackPluginScoreboards = getBoolean("settings.track-plugin-scoreboards", false);
}
+ public static boolean fixEntityPositionDesync = true;
+ private static void fixEntityPositionDesync() {
+ fixEntityPositionDesync = getBoolean("settings.fix-entity-position-desync", fixEntityPositionDesync);
+ }
+
public static void registerCommands() {
for (Map.Entry<String, Command> entry : commands.entrySet()) {
MinecraftServer.getServer().server.getCommandMap().register(entry.getKey(), "Paper", entry.getValue());
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 e12eb951d52d4bfa30e1d25139444d7663d3b946..b3ba775d4c4674dc8cd85145cacf9ca93737fe04 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -3746,6 +3746,16 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, i
}
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);