From 30499c8b3061560751fc5f1b27a83d4480ef8949 Mon Sep 17 00:00:00 2001
From: Nassim Jahnke <nassim@njahnke.dev>
Date: Wed, 27 Nov 2024 21:47:40 +0100
Subject: [PATCH] Fix entity teleport for non-self in 1.21.2->1.21.1 Fixes #922

---
 .../rewriter/EntityPacketRewriter1_21_2.java    | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_2to1_21/rewriter/EntityPacketRewriter1_21_2.java b/common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_2to1_21/rewriter/EntityPacketRewriter1_21_2.java
index 49d57c89..39ec3bac 100644
--- a/common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_2to1_21/rewriter/EntityPacketRewriter1_21_2.java
+++ b/common/src/main/java/com/viaversion/viabackwards/protocol/v1_21_2to1_21/rewriter/EntityPacketRewriter1_21_2.java
@@ -46,6 +46,7 @@ import com.viaversion.viaversion.util.Key;
 import java.util.ArrayList;
 import java.util.BitSet;
 import java.util.List;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 public final class EntityPacketRewriter1_21_2 extends EntityRewriter<ClientboundPacket1_21_2, Protocol1_21_2To1_21> {
 
@@ -196,7 +197,7 @@ public final class EntityPacketRewriter1_21_2 extends EntityRewriter<Clientbound
         });
 
         protocol.registerClientbound(ClientboundPackets1_21_2.TELEPORT_ENTITY, wrapper -> {
-            wrapper.passthrough(Types.VAR_INT); // Entity ID
+            final int entityId = wrapper.passthrough(Types.VAR_INT);
             final double x = wrapper.passthrough(Types.DOUBLE);
             final double y = wrapper.passthrough(Types.DOUBLE);
             final double z = wrapper.passthrough(Types.DOUBLE);
@@ -215,7 +216,7 @@ public final class EntityPacketRewriter1_21_2 extends EntityRewriter<Clientbound
             wrapper.send(Protocol1_21_2To1_21.class);
             wrapper.cancel();
 
-            handleRelativeArguments(wrapper, x, y, z, yaw, pitch, relativeArguments, movementX, movementY, movementZ);
+            handleRelativeArguments(wrapper, x, y, z, yaw, pitch, relativeArguments, movementX, movementY, movementZ, entityId);
         });
 
         protocol.registerClientbound(ClientboundPackets1_21_2.PLAYER_POSITION, wrapper -> {
@@ -241,7 +242,7 @@ public final class EntityPacketRewriter1_21_2 extends EntityRewriter<Clientbound
             wrapper.send(Protocol1_21_2To1_21.class);
             wrapper.cancel();
 
-            handleRelativeArguments(wrapper, x, y, z, yaw, pitch, relativeArguments, movementX, movementY, movementZ);
+            handleRelativeArguments(wrapper, x, y, z, yaw, pitch, relativeArguments, movementX, movementY, movementZ, null);
         });
 
         protocol.registerServerbound(ServerboundPackets1_20_5.PLAYER_COMMAND, wrapper -> {
@@ -437,7 +438,8 @@ public final class EntityPacketRewriter1_21_2 extends EntityRewriter<Clientbound
         double x, double y, double z,
         float yaw, float pitch,
         final int relativeArguments,
-        double movementX, double movementY, double movementZ
+        double movementX, double movementY, double movementZ,
+        @Nullable final Integer entityId
     ) {
         // Position and rotation
         final PlayerStorage storage = wrapper.user().get(PlayerStorage.class);
@@ -478,6 +480,11 @@ public final class EntityPacketRewriter1_21_2 extends EntityRewriter<Clientbound
 
         // Movement
         if (relativeDeltaX && relativeDeltaY && relativeDeltaZ) {
+            if (entityId != null && entityId != tracker(wrapper.user()).clientEntityId()) {
+                // Can only handle the client entity
+                return;
+            }
+
             final PacketWrapper explosionPacket = wrapper.create(ClientboundPackets1_21.EXPLODE);
             explosionPacket.write(Types.DOUBLE, 0.0); // Center X
             explosionPacket.write(Types.DOUBLE, 0.0); // Center Y
@@ -495,7 +502,7 @@ public final class EntityPacketRewriter1_21_2 extends EntityRewriter<Clientbound
             explosionPacket.send(Protocol1_21_2To1_21.class);
         } else if (!relativeDeltaX && !relativeDeltaY && !relativeDeltaZ) {
             final PacketWrapper entityMotionPacket = wrapper.create(ClientboundPackets1_21.SET_ENTITY_MOTION);
-            entityMotionPacket.write(Types.VAR_INT, tracker(wrapper.user()).clientEntityId());
+            entityMotionPacket.write(Types.VAR_INT, entityId != null ? entityId : tracker(wrapper.user()).clientEntityId());
             entityMotionPacket.write(Types.SHORT, (short) (movementX * 8000));
             entityMotionPacket.write(Types.SHORT, (short) (movementY * 8000));
             entityMotionPacket.write(Types.SHORT, (short) (movementZ * 8000));