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 02bf2705ca1c99023a83a22d92e1962181102297..0f99733660f91280e4c6262cf75b3c9cae86f65a 100644
--- a/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java
+++ b/src/main/java/net/minecraft/network/syncher/SynchedEntityData.java
@@ -50,7 +50,7 @@ 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
     }
 
@@ -151,6 +151,20 @@ 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 e9dcdb1e09e84a9b451034ff4bdfa6eae2dd1c04..24b1715397ba8e6f5e9841a030d0e3d964356f89 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
@@ -561,6 +561,7 @@ 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);
@@ -612,6 +613,11 @@ 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 a8debfad8c8e66099f8a9aedc6f1971a8576dade..7796e191747be545e744564a2b0b65790f69114d 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -1949,6 +1949,7 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
             }
 
             if (cancelled) {
+                this.player.resyncUsingItem(this.player); // Paper - Properly cancel usable items
                 this.player.getBukkitEntity().updateInventory(); // SPIGOT-2524
                 return;
             }
@@ -2718,7 +2719,7 @@ 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)) {
-                                entity.getBukkitEntity().update(ServerGamePacketListenerImpl.this.player);
+                                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 0d0b07c9199be9ca0d5ac3feb1d44f149ba69283..3d30427e75bdfb9cf453fb5cd2a344227da1641a 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -393,7 +393,7 @@ 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 139a5cd05a167b3b3330aa94bd33d193dce19e2d..1a40128b06e70e39a82f170fc16dcae1e22c745c 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -664,13 +664,44 @@ 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 25a7dfddb44a11f6e20c459141a61270c0c12d4c..e980c8c356b30d25e2fc5a73b91ad2c6edd4fe05 100644
--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
+++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
@@ -3840,6 +3840,11 @@ 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 b586116d8cca1585f9c9e618ed4d0cb2ef2747be..acf38ef6d8de8b15cf2b09eb7bda390c4e446e9a 100644
--- a/src/main/java/net/minecraft/world/entity/animal/Bucketable.java
+++ b/src/main/java/net/minecraft/world/entity/animal/Bucketable.java
@@ -108,8 +108,7 @@ 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
-                entity.getBukkitEntity().update((ServerPlayer) player); // 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 b8eb9166e44da8745a056bf68f2f9316ce25d7a7..2cde808bfa797256409879505ba205a71f381981 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
@@ -1012,7 +1012,11 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
             return;
         }
 
-        entityTracker.broadcast(this.getHandle().getAddEntityPacket(entityTracker.serverEntity));
+        // Paper start - resend possibly desynced entity instead of add entity packet
+        for (final ServerPlayerConnection connection : entityTracker.seenBy) {
+            this.getHandle().resendPossiblyDesyncedEntityData(connection.getPlayer());
+        }
+        // Paper end - resend possibly desynced entity instead of add entity packet
     }
 
     public void update(ServerPlayer player) {
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java
index f3a9b3380246fb2dd4b60a8d1a94c5dfed98d316..350ad61ab3fe66abd528e353b431a4a6dac17506 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftItemFrame.java
@@ -39,9 +39,11 @@ 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) {
