From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Tue, 16 Feb 2021 00:16:56 -0800
Subject: [PATCH] Send full pos packets for hard colliding entities

Prevent collision problems due to desync (i.e boats)

Configurable under
`send-full-pos-for-hard-colliding-entities`

diff --git a/src/main/java/com/destroystokyo/paper/PaperConfig.java b/src/main/java/com/destroystokyo/paper/PaperConfig.java
index 31662010b1c3d3fb9f667afd13e33e0a35005867..b3f4ac2ce6f515e406d2f31b1d2429729c9e2b60 100644
--- a/src/main/java/com/destroystokyo/paper/PaperConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperConfig.java
@@ -651,4 +651,10 @@ public class PaperConfig {
     private static void lagCompensateBlockBreaking() {
         lagCompensateBlockBreaking = getBoolean("settings.lag-compensate-block-breaking", true);
     }
+
+    public static boolean sendFullPosForHardCollidingEntities;
+
+    private static void sendFullPosForHardCollidingEntities() {
+        sendFullPosForHardCollidingEntities = getBoolean("settings.send-full-pos-for-hard-colliding-entities", true);
+    }
 }
diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index 9950541e0432240207458274b76b1c5d402ac704..b7c9294fdd3d799d410afba4a1118aa371c98533 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -173,7 +173,7 @@ public class ServerEntity {
                     // Paper end - remove allocation of Vec3D here
                     boolean flag4 = k < -32768L || k > 32767L || l < -32768L || l > 32767L || i1 < -32768L || i1 > 32767L;
 
-                    if (!flag4 && this.teleportDelay <= 400 && !this.wasRiding && this.wasOnGround == this.entity.isOnGround()) {
+                    if (!flag4 && this.teleportDelay <= 400 && !this.wasRiding && this.wasOnGround == this.entity.isOnGround() && !(com.destroystokyo.paper.PaperConfig.sendFullPosForHardCollidingEntities && this.entity.hardCollides())) { // Paper - send full pos for hard colliding entities to prevent collision problems due to desync
                         if ((!flag2 || !flag3) && !(this.entity instanceof AbstractArrow)) {
                             if (flag2) {
                                 packet1 = new ClientboundMoveEntityPacket.Pos(this.entity.getId(), (short) ((int) k), (short) ((int) l), (short) ((int) i1), this.entity.isOnGround());