PaperMC/patches/server/Properly-resend-entities.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
Date: Wed, 7 Dec 2022 17:25:19 -0500
Subject: [PATCH] Properly resend entities

This resolves some issues which caused entities to not be resent correctly.
Entities that are interacted with need to be resent to the client, so we resend all the entity
data to the player whilst making sure not to clear dirty entries from the tracker. This makes
sure that values will be correctly updated to other players.

This also adds utilities to aid in further preventing entity desyncs.

This also also fixes the bug causing cancelling PlayerInteractEvent to cause items to continue
to be used despite being cancelled on the server.

For example, items being consumed but never finishing, shields being put up, etc.
The underlying issue of this is that the client modifies their synced data values,
and so we have to (forcibly) resend them in order for the client to reset their using item state.

See: https://github.com/PaperMC/Paper/pull/1896

== AT ==
public net.minecraft.server.level.ChunkMap$TrackedEntity serverEntity

diff --git a/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java b/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java
+++ b/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java
@@ -0,0 +0,0 @@ public class SynchedEntityData {
         }
     }
 
-    private <T> SynchedEntityData.DataItem<T> getItem(EntityDataAccessor<T> key) {
+    public <T> SynchedEntityData.DataItem<T> getItem(EntityDataAccessor<T> key) { // Paper - public
         return (SynchedEntityData.DataItem<T>) this.itemsById[key.id()]; // CraftBukkit - decompile error
     }
 
@@ -0,0 +0,0 @@ public class SynchedEntityData {
         }
     }
 
+    // Paper start
+    // We need to pack all as we cannot rely on "non default values" or "dirty" ones.
+    // Because these values can possibly be desynced on the client.
+    @Nullable
+    public List<SynchedEntityData.DataValue<?>> packAll() {
+        final List<SynchedEntityData.DataValue<?>> list = new ArrayList<>();
+        for (final DataItem<?> dataItem : this.itemsById) {
+            list.add(dataItem.value());
+        }
+
+        return list;
+    }
+    // Paper end
+
     public static class DataItem<T> {
 
         final EntityDataAccessor<T> accessor;
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
@@ -0,0 +0,0 @@ public class ServerPlayerGameMode {
             }
             // Paper end - extend Player Interact cancellation
             player.getBukkitEntity().updateInventory(); // SPIGOT-2867
+            this.player.resyncUsingItem(this.player); // Paper - Properly cancel usable items
             return (event.useItemInHand() != Event.Result.ALLOW) ? InteractionResult.SUCCESS : InteractionResult.PASS;
         } else if (this.gameModeForPlayer == GameType.SPECTATOR) {
             MenuProvider itileinventory = iblockdata.getMenuProvider(world, blockposition);
@@ -0,0 +0,0 @@ public class ServerPlayerGameMode {
 
                 return enuminteractionresult;
             } else {
+                // Paper start - Properly cancel usable items; Cancel only if cancelled + if the interact result is different from default response
+                if (this.interactResult && this.interactResult != cancelledItem) {
+                    this.player.resyncUsingItem(this.player);
+                }
+                // Paper end - Properly cancel usable items
                 return InteractionResult.PASS;
             }
         }
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -0,0 +0,0 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
             }
 
             if (cancelled) {
+                this.player.resyncUsingItem(this.player); // Paper - Properly cancel usable items
                 this.player.getBukkitEntity().updateInventory(); // SPIGOT-2524
                 return;
             }
@@ -0,0 +0,0 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
 
                             // Entity in bucket - SPIGOT-4048 and SPIGOT-6859a
                             if ((entity instanceof Bucketable && entity instanceof LivingEntity && origItem != null && origItem.asItem() == Items.WATER_BUCKET) && (event.isCancelled() || ServerGamePacketListenerImpl.this.player.getInventory().getSelected() == null || ServerGamePacketListenerImpl.this.player.getInventory().getSelected().getItem() != origItem)) {
-                                ServerGamePacketListenerImpl.this.send(new ClientboundAddEntityPacket(entity));
+                                entity.resendPossiblyDesyncedEntityData(ServerGamePacketListenerImpl.this.player); // Paper - The entire mob gets deleted, so resend it.
                                 ServerGamePacketListenerImpl.this.player.containerMenu.sendAllDataToRemote();
                             }
 
diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -0,0 +0,0 @@ public abstract class PlayerList {
         ((ServerLevel)player.level()).getChunkSource().chunkMap.addEntity(player); // Paper - Fire PlayerJoinEvent when Player is actually ready; track entity now
         // CraftBukkit end
 
-        player.refreshEntityData(player); // CraftBukkit - BungeeCord#2321, send complete data to self on spawn
+        //player.refreshEntityData(player); // CraftBukkit - BungeeCord#2321, send complete data to self on spawn // Paper - THIS IS NOT NEEDED ANYMORE
 
         this.sendLevelInfo(player, worldserver1);
 
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
 
     // CraftBukkit start
     public void refreshEntityData(ServerPlayer to) {
-        List<SynchedEntityData.DataValue<?>> list = this.getEntityData().getNonDefaultValues();
+        List<SynchedEntityData.DataValue<?>> list = this.entityData.packAll(); // Paper - Update EVERYTHING not just not default
 
-        if (list != null) {
+        if (list != null && to.getBukkitEntity().canSee(this.getBukkitEntity())) { // Paper
             to.connection.send(new ClientboundSetEntityDataPacket(this.getId(), list));
         }
     }
     // CraftBukkit end
+    // Paper start
+    // This method should only be used if the data of an entity could have become desynced
+    // due to interactions on the client.
+    public void resendPossiblyDesyncedEntityData(net.minecraft.server.level.ServerPlayer player) {
+        if (this.tracker == null) {
+            return;
+        }
+
+        if (player.getBukkitEntity().canSee(this.getBukkitEntity())) {
+            final net.minecraft.server.level.ServerEntity serverEntity = this.tracker.serverEntity;
+            final List<net.minecraft.network.protocol.Packet<? super net.minecraft.network.protocol.game.ClientGamePacketListener>> list = new java.util.ArrayList<>();
+            serverEntity.sendPairingData(player, list::add);
+            player.connection.send(new net.minecraft.network.protocol.game.ClientboundBundlePacket(list));
+        }
+    }
+
+    // This method allows you to specifically resend certain data accessor keys to the client
+    public void resendPossiblyDesyncedDataValues(List<EntityDataAccessor<?>> keys, ServerPlayer to) {
+        if (!to.getBukkitEntity().canSee(this.getBukkitEntity())) {
+            return;
+        }
+
+        final List<SynchedEntityData.DataValue<?>> values = new java.util.ArrayList<>(keys.size());
+        for (final EntityDataAccessor<?> key : keys) {
+            final SynchedEntityData.DataItem<?> synchedValue = this.entityData.getItem(key);
+            values.add(synchedValue.value());
+        }
+
+        to.connection.send(new ClientboundSetEntityDataPacket(this.id, values));
+    }
+    // Paper end
 
     public boolean equals(Object object) {
         return object instanceof Entity ? ((Entity) object).id == this.id : false;
diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -0,0 +0,0 @@ public abstract class LivingEntity extends Entity implements Attackable {
         return ((Byte) this.entityData.get(LivingEntity.DATA_LIVING_ENTITY_FLAGS) & 2) > 0 ? InteractionHand.OFF_HAND : InteractionHand.MAIN_HAND;
     }
 
+    // Paper start - Properly cancel usable items
+    public void resyncUsingItem(ServerPlayer serverPlayer) {
+        this.resendPossiblyDesyncedDataValues(java.util.List.of(DATA_LIVING_ENTITY_FLAGS), serverPlayer);
+    }
+    // Paper end - Properly cancel usable items
     private void updatingUsingItem() {
         if (this.isUsingItem()) {
             if (ItemStack.isSameItem(this.getItemInHand(this.getUsedItemHand()), this.useItem)) {
diff --git a/src/main/java/net/minecraft/world/entity/animal/Bucketable.java b/src/main/java/net/minecraft/world/entity/animal/Bucketable.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/animal/Bucketable.java
+++ b/src/main/java/net/minecraft/world/entity/animal/Bucketable.java
@@ -0,0 +0,0 @@ public interface Bucketable {
             itemstack1 = CraftItemStack.asNMSCopy(playerBucketFishEvent.getEntityBucket());
             if (playerBucketFishEvent.isCancelled()) {
                 ((ServerPlayer) player).containerMenu.sendAllDataToRemote(); // We need to update inventory to resync client's bucket
-                ((ServerPlayer) player).connection.send(new ClientboundAddEntityPacket(entity)); // We need to play out these packets as the client assumes the fish is gone
-                entity.refreshEntityData((ServerPlayer) player); // Need to send data such as the display name to client
+                entity.resendPossiblyDesyncedEntityData((ServerPlayer) player); // Paper
                 return Optional.of(InteractionResult.FAIL);
             }
             entity.playSound(((Bucketable) entity).getPickupSound(), 1.0F, 1.0F);
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
@@ -0,0 +0,0 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
             return;
         }
 
-        entityTracker.broadcast(this.getHandle().getAddEntityPacket());
+        // Paper start, resend possibly desynced entity instead of add entity packet
+        for (ServerPlayerConnection playerConnection : entityTracker.seenBy) {
+            this.getHandle().resendPossiblyDesyncedEntityData(playerConnection.getPlayer());
+        }
+        // Paper end
     }
 
     private static PermissibleBase getPermissibleBase() {
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java
@@ -0,0 +0,0 @@ public class CraftItemFrame extends CraftHanging implements ItemFrame {
     protected void update() {
         super.update();
 
+        // Paper start, don't mark as dirty as this is handled in super.update()
         // mark dirty, so that the client gets updated with item and rotation
-        this.getHandle().getEntityData().markDirty(net.minecraft.world.entity.decoration.ItemFrame.DATA_ITEM);
-        this.getHandle().getEntityData().markDirty(net.minecraft.world.entity.decoration.ItemFrame.DATA_ROTATION);
+        //this.getHandle().getEntityData().markDirty(net.minecraft.world.entity.decoration.ItemFrame.DATA_ITEM);
+        //this.getHandle().getEntityData().markDirty(net.minecraft.world.entity.decoration.ItemFrame.DATA_ROTATION);
+        // Paper end
 
         // update redstone
         if (!this.getHandle().generation) {