From 3c048e89df0608e4a5187df2ddc1c36956b11df5 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Thu, 8 Nov 2018 04:53:00 +0000
Subject: [PATCH] Extend BlockStateListPopulator

extends BlockStateListPopulator to suppport checking block types in the
physical world it's representing, allowing for blocks making modifications
to the world to maintain proper state.

diff --git a/src/main/java/net/minecraft/server/BlockSponge.java b/src/main/java/net/minecraft/server/BlockSponge.java
index 987af9c3de..6e52d46952 100644
--- a/src/main/java/net/minecraft/server/BlockSponge.java
+++ b/src/main/java/net/minecraft/server/BlockSponge.java
@@ -68,7 +68,7 @@ public class BlockSponge extends Block {
                             linkedlist.add(new Tuple(blockposition2, Integer.valueOf(j + 1)));
                         }
                     } else if (material == Material.WATER_PLANT || material == Material.REPLACEABLE_WATER_PLANT) {
-                        // iblockdata.a(world, blockposition2, 0);
+                        iblockdata.a(blockList, blockposition2, 0); // Paper
                         blockList.setTypeAndData(blockposition2, Blocks.AIR.getBlockData(), 3); // CraftBukkit
                         ++i;
                         if (j < 6) {
@@ -96,12 +96,14 @@ public class BlockSponge extends Block {
 
             for (CraftBlockState block : blocks) {
                 BlockPosition blockposition2 = new BlockPosition(block.getX(), block.getY(), block.getZ());
+                /* // Paper start
                 IBlockData iblockdata = world.getType(blockposition2);
                 Material material = iblockdata.getMaterial();
 
                 if (material == Material.WATER_PLANT || material == Material.REPLACEABLE_WATER_PLANT) {
                     iblockdata.a(world, blockposition2, 0);
                 }
+                */ // Paper end
 
                 world.setTypeAndData(blockposition2, block.getHandle(), block.getFlag());
             }
diff --git a/src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java b/src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java
index 165843ddfe..8482abd054 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/BlockStateListPopulator.java
@@ -4,8 +4,12 @@ import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
 
+import net.minecraft.server.Block;
 import net.minecraft.server.BlockPosition;
+import net.minecraft.server.FluidType;
 import net.minecraft.server.IBlockData;
+import net.minecraft.server.TickList;
+import net.minecraft.server.TickListPriority;
 import net.minecraft.server.World;
 
 import org.bukkit.block.BlockState;
@@ -14,6 +18,41 @@ import org.bukkit.craftbukkit.block.CraftBlockState;
 public class BlockStateListPopulator extends DummyGeneratorAccess {
     private final World world;
     private final LinkedHashMap<BlockPosition, CraftBlockState> list;
+    // Paper start
+    private final TickList<FluidType> fluidTickList = new TickList<FluidType>() {
+        @Override
+        public boolean a(BlockPosition var1, FluidType var2) {
+            return BlockStateListPopulator.super.I().a(var1, var2);
+        }
+
+        @Override
+        public void a(BlockPosition var1, FluidType var2, int var3, TickListPriority var4) {
+
+        }
+
+        @Override
+        public boolean b(BlockPosition var1, FluidType var2) {
+            return false;
+        }
+    };
+
+    private TickList<Block> blockTickList = new TickList<Block>() {
+        @Override
+        public boolean a(BlockPosition var1, Block var2) {
+            return BlockStateListPopulator.super.J().a(var1, var2);
+        }
+
+        @Override
+        public void a(BlockPosition var1, Block var2, int var3, TickListPriority var4) {
+
+        }
+
+        @Override
+        public boolean b(BlockPosition var1, Block var2) {
+            return false;
+        }
+    };
+    // Paper end
 
     public BlockStateListPopulator(World world) {
         this(world, new LinkedHashMap<>());
@@ -45,4 +84,34 @@ public class BlockStateListPopulator extends DummyGeneratorAccess {
     public World getWorld() {
         return world;
     }
+
+    // Paper start
+    @Override
+    public IBlockData getType(BlockPosition bp) {
+        CraftBlockState craftState = list.get(bp);
+        if (craftState != null) {
+            return craftState.getHandle();
+        } else {
+            return world.getType(bp);
+        }
+    }
+
+    // Do nothing, this will be ran when the block is actually placed into the world
+    @Override
+    public void update(BlockPosition bp, Block block) {}
+
+    // Dumb tick lists, we rely upon block placement into the world updating this info
+    // no obfhelpers intentional, design of these classes do not favor them, and easier
+    // to just rework on upgrade...
+    @Override
+    public TickList<FluidType> I() {
+        return fluidTickList;
+    }
+
+    @Override
+    public TickList<Block> J() {
+        return blockTickList;
+    }
+
+    // paper end
 }
-- 
2.19.1