Paper/patches/server/0167-use-CB-BlockState-implementations-for-captured-block.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Thu, 16 Nov 2017 12:12:41 +0000
Subject: [PATCH] use CB BlockState implementations for captured blocks

When modifying the world, CB will store a copy of the affected
blocks in order to restore their state in the case that the event
is cancelled. This change only modifies the collection of blocks
in the world by normal means, e.g. not during tree population,
as the potentially marginal overheads would serve no advantage.

CB was using a CraftBlockState for all blocks, which causes issues
should any block that uses information beyond a data ID would suffer
from missing information, e.g. Skulls.

By using CBs CraftBlock#getState(), we will maintain a proper copy of
the blockstate that will be valid for restoration, as opposed to dropping
information on restoration when the event is cancelled.

diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 73ff83f2c3a6b9796305abd5a98e8a77f7a44240..cd2278765439f4dc1652d997c8e0174af9b180cb 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -142,7 +142,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
     public boolean preventPoiUpdated = false; // CraftBukkit - SPIGOT-5710
     public boolean captureBlockStates = false;
     public boolean captureTreeGeneration = false;
-    public Map<BlockPos, CapturedBlockState> capturedBlockStates = new java.util.LinkedHashMap<>();
+    public Map<BlockPos, org.bukkit.craftbukkit.block.CraftBlockState> capturedBlockStates = new java.util.LinkedHashMap<>(); // Paper
     public Map<BlockPos, BlockEntity> capturedTileEntities = new HashMap<>();
     public List<ItemEntity> captureDrops;
     public long ticksPerAnimalSpawns;
@@ -363,7 +363,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
     public boolean setBlock(BlockPos pos, BlockState state, int flags, int maxUpdateDepth) {
         // CraftBukkit start - tree generation
         if (this.captureTreeGeneration) {
-            CapturedBlockState blockstate = this.capturedBlockStates.get(pos);
+            CraftBlockState blockstate = this.capturedBlockStates.get(pos);
             if (blockstate == null) {
                 blockstate = CapturedBlockState.getTreeBlockState(this, pos, flags);
                 this.capturedBlockStates.put(pos.immutable(), blockstate);
@@ -383,7 +383,8 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
             // CraftBukkit start - capture blockstates
             boolean captured = false;
             if (this.captureBlockStates && !this.capturedBlockStates.containsKey(pos)) {
-                CapturedBlockState blockstate = CapturedBlockState.getBlockState(this, pos, flags);
+                CraftBlockState blockstate = (CraftBlockState) world.getBlockAt(pos.getX(), pos.getY(), pos.getZ()).getState(); // Paper - use CB getState to get a suitable snapshot
+                blockstate.setFlag(flags); // Paper - set flag
                 this.capturedBlockStates.put(pos.immutable(), blockstate);
                 captured = true;
             }
@@ -652,7 +653,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
     public BlockState getBlockState(BlockPos pos) {
         // CraftBukkit start - tree generation
         if (this.captureTreeGeneration) {
-            CapturedBlockState previous = this.capturedBlockStates.get(pos);
+            CraftBlockState previous = this.capturedBlockStates.get(pos); // Paper
             if (previous != null) {
                 return previous.getHandle();
             }