From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Tue, 22 Nov 2016 00:40:42 -0500
Subject: [PATCH] Fix client rendering skulls from same user

See: https://github.com/PaperMC/Paper/issues/1304

Changes the UUID sent to client to be based on either
the texture payload, or random.

This allows the client to render multiple skull textures from the same user,
for when different skins were used when skull was made.

diff --git a/src/main/java/net/minecraft/network/FriendlyByteBuf.java b/src/main/java/net/minecraft/network/FriendlyByteBuf.java
index 303b877bc467de7c046cc221d061fac841c1d9f3..896a4237f871d46cf39b0721e909c2cc3b5fc728 100644
--- a/src/main/java/net/minecraft/network/FriendlyByteBuf.java
+++ b/src/main/java/net/minecraft/network/FriendlyByteBuf.java
@@ -496,9 +496,18 @@ public class FriendlyByteBuf extends ByteBuf {
             if (item.canBeDepleted() || item.shouldOverrideMultiplayerNbt()) {
                 // Spigot start - filter
                 stack = stack.copy();
-                CraftItemStack.setItemMeta(stack, CraftItemStack.getItemMeta(stack));
+                // CraftItemStack.setItemMeta(stack, CraftItemStack.getItemMeta(stack)); // Paper - This is no longer needed due to NBT being supported
                 // Spigot end
                 nbttagcompound = stack.getTag();
+                // Paper start
+                if (nbttagcompound != null && nbttagcompound.contains("SkullOwner", 10)) {
+                    CompoundTag owner = nbttagcompound.getCompound("SkullOwner");
+                    if (owner.hasUUID("Id")) {
+                        nbttagcompound.putUUID("SkullOwnerOrig", owner.getUUID("Id"));
+                        net.minecraft.world.level.block.entity.SkullBlockEntity.sanitizeUUID(owner);
+                    }
+                }
+                // Paper end
             }
 
             this.writeNbt(nbttagcompound);
@@ -518,7 +527,16 @@ public class FriendlyByteBuf extends ByteBuf {
             itemstack.setTag(this.readNbt());
             // CraftBukkit start
             if (itemstack.getTag() != null) {
-                CraftItemStack.setItemMeta(itemstack, CraftItemStack.getItemMeta(itemstack));
+                // Paper start - Fix skulls of same owner - restore orig ID since we changed it on send to client
+                if (itemstack.tag.contains("SkullOwnerOrig")) {
+                    CompoundTag owner = itemstack.tag.getCompound("SkullOwner");
+                    if (itemstack.tag.contains("SkullOwnerOrig")) {
+                        owner.tags.put("Id", itemstack.tag.tags.get("SkullOwnerOrig"));
+                        itemstack.tag.remove("SkullOwnerOrig");
+                    }
+                }
+                // Paper end
+                // CraftItemStack.setItemMeta(itemstack, CraftItemStack.getItemMeta(itemstack)); // Paper - This is no longer needed due to NBT being supported
             }
             // CraftBukkit end
             return itemstack;
diff --git a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacketData.java b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacketData.java
index aec78b6079c3404d934d2b46bc0d2f9d2a871b6d..36d9308a11bde0a631de037cf1bcae1062eaa5d9 100644
--- a/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacketData.java
+++ b/src/main/java/net/minecraft/network/protocol/game/ClientboundLevelChunkPacketData.java
@@ -152,6 +152,7 @@ public class ClientboundLevelChunkPacketData {
         static ClientboundLevelChunkPacketData.BlockEntityInfo create(BlockEntity blockEntity) {
             CompoundTag compoundTag = blockEntity.getUpdateTag();
             BlockPos blockPos = blockEntity.getBlockPos();
+            if (blockEntity instanceof net.minecraft.world.level.block.entity.SkullBlockEntity) { net.minecraft.world.level.block.entity.SkullBlockEntity.sanitizeTileEntityUUID(compoundTag); } // Paper
             int i = SectionPos.sectionRelative(blockPos.getX()) << 4 | SectionPos.sectionRelative(blockPos.getZ());
             return new ClientboundLevelChunkPacketData.BlockEntityInfo(i, blockPos.getY(), blockEntity.getType(), compoundTag.isEmpty() ? null : compoundTag);
         }
diff --git a/src/main/java/net/minecraft/world/level/block/entity/SkullBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/SkullBlockEntity.java
index 2a49aa1d387949e33708f5f13261e5257ea4aa2f..e3efea8623c7d34915069a6b9b7da9f2b1694c28 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/SkullBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/SkullBlockEntity.java
@@ -11,6 +11,7 @@ import javax.annotation.Nullable;
 import net.minecraft.Util;
 import net.minecraft.core.BlockPos;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
 import net.minecraft.nbt.NbtUtils;
 import net.minecraft.network.protocol.game.ClientboundBlockEntityDataPacket;
 import net.minecraft.server.players.GameProfileCache;
@@ -93,9 +94,37 @@ public class SkullBlockEntity extends BlockEntity {
 
     @Override
     public ClientboundBlockEntityDataPacket getUpdatePacket() {
-        return ClientboundBlockEntityDataPacket.create(this);
+        return ClientboundBlockEntityDataPacket.create(this, e -> sanitizeTileEntityUUID(e.getUpdateTag())); // Paper
     }
 
+    // Paper start
+    public static CompoundTag sanitizeTileEntityUUID(CompoundTag cmp) {
+        CompoundTag owner = cmp.getCompound("Owner");
+        if (!owner.isEmpty()) {
+            sanitizeUUID(owner);
+        }
+        return cmp;
+    }
+
+    public static void sanitizeUUID(CompoundTag owner) {
+        CompoundTag properties = owner.getCompound("Properties");
+        ListTag list = null;
+        if (!properties.isEmpty()) {
+            list = properties.getList("textures", 10);
+        }
+
+        if (list != null && !list.isEmpty()) {
+            String textures = ((CompoundTag)list.get(0)).getString("Value");
+            if (textures != null && textures.length() > 3) {
+                UUID uuid = UUID.nameUUIDFromBytes(textures.getBytes());
+                owner.putUUID("Id", uuid);
+                return;
+            }
+        }
+        owner.putUUID("Id", UUID.randomUUID());
+    }
+    // Paper end
+
     @Override
     public CompoundTag getUpdateTag() {
         return this.saveWithoutMetadata();