PaperMC/nms-patches/Chunk.patch

--- a/net/minecraft/server/Chunk.java
+++ b/net/minecraft/server/Chunk.java
@@ -14,6 +14,9 @@
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
+import com.google.common.collect.Lists; // CraftBukkit
+import org.bukkit.Bukkit; // CraftBukkit
+
 public class Chunk {
 
     private static final Logger e = LogManager.getLogger();
@@ -42,6 +45,34 @@
     private ConcurrentLinkedQueue<BlockPosition> y;
     public boolean d;
 
+    // CraftBukkit start - Neighbor loaded cache for chunk lighting and entity ticking
+    private int neighbors = 0x1 << 12;
+
+    public boolean areNeighborsLoaded(final int radius) {
+        switch (radius) {
+            case 2:
+                return this.neighbors == Integer.MAX_VALUE >> 6;
+            case 1:
+                final int mask =
+                        //       x        z   offset          x        z   offset          x         z   offset
+                        (0x1 << (1 * 5 +  1 + 12)) | (0x1 << (0 * 5 +  1 + 12)) | (0x1 << (-1 * 5 +  1 + 12)) |
+                        (0x1 << (1 * 5 +  0 + 12)) | (0x1 << (0 * 5 +  0 + 12)) | (0x1 << (-1 * 5 +  0 + 12)) |
+                        (0x1 << (1 * 5 + -1 + 12)) | (0x1 << (0 * 5 + -1 + 12)) | (0x1 << (-1 * 5 + -1 + 12));
+                return (this.neighbors & mask) == mask;
+            default:
+                throw new UnsupportedOperationException(String.valueOf(radius));
+        }
+    }
+
+    public void setNeighborLoaded(final int x, final int z) {
+        this.neighbors |= 0x1 << (x * 5 + 12 + z);
+    }
+
+    public void setNeighborUnloaded(final int x, final int z) {
+        this.neighbors &= ~(0x1 << (x * 5 + 12 + z));
+    }
+    // CraftBukkit end
+
     public Chunk(World world, int i, int j) {
         this.sections = new ChunkSection[16];
         this.g = new byte[256];
@@ -62,8 +93,14 @@
 
         Arrays.fill(this.h, -999);
         Arrays.fill(this.g, (byte) -1);
+        // CraftBukkit start
+        this.bukkitChunk = new org.bukkit.craftbukkit.CraftChunk(this);
     }
 
+    public org.bukkit.Chunk bukkitChunk;
+    public boolean mustSave;
+    // CraftBukkit end
+
     public Chunk(World world, ChunkSnapshot chunksnapshot, int i, int j) {
         this(world, i, j);
         boolean flag = true;
@@ -467,7 +504,8 @@
                     }
                 }
 
-                if (!this.world.isClientSide && block1 != block) {
+                // CraftBukkit - Don't place while processing the BlockPlaceEvent, unless it's a BlockContainer. Prevents blocks such as TNT from activating when cancelled.
+                if (!this.world.isClientSide && block1 != block  && (!this.world.captureBlockStates || block instanceof BlockTileEntity)) {
                     block.onPlace(this.world, blockposition, iblockdata);
                 }
 
@@ -604,7 +642,15 @@
 
     @Nullable
     public TileEntity a(BlockPosition blockposition, Chunk.EnumTileEntityState chunk_enumtileentitystate) {
-        TileEntity tileentity = (TileEntity) this.tileEntities.get(blockposition);
+        // CraftBukkit start
+        TileEntity tileentity = null;
+        if (world.captureBlockStates) {
+            tileentity = world.capturedTileEntities.get(blockposition);
+        }
+        if (tileentity == null) {
+            tileentity = (TileEntity) this.tileEntities.get(blockposition);
+        }
+        // CraftBukkit end
 
         if (tileentity == null) {
             if (chunk_enumtileentitystate == Chunk.EnumTileEntityState.IMMEDIATE) {
@@ -639,6 +685,13 @@
 
             tileentity.z();
             this.tileEntities.put(blockposition, tileentity);
+            // CraftBukkit start
+        } else {
+            System.out.println("Attempted to place a tile entity (" + tileentity + ") at " + tileentity.position.getX() + "," + tileentity.position.getY() + "," + tileentity.position.getZ()
+                + " (" + org.bukkit.craftbukkit.util.CraftMagicNumbers.getMaterial(getBlockData(blockposition).getBlock()) + ") where there was no entity tile!");
+            System.out.println("Chunk coordinates: " + (this.locX * 16) + "," + (this.locZ * 16));
+            new Exception().printStackTrace();
+            // CraftBukkit end
         }
     }
 
@@ -681,9 +734,21 @@
         int i = aentityslice.length;
 
         for (int j = 0; j < i; ++j) {
-            EntitySlice entityslice = aentityslice[j];
+            // CraftBukkit start
+            List<Entity> newList = Lists.newArrayList(aentityslice[j]);
+            java.util.Iterator<Entity> iter = newList.iterator();
+            while (iter.hasNext()) {
+                Entity entity = iter.next();
 
-            this.world.c((Collection) entityslice);
+                // Do not pass along players, as doing so can get them stuck outside of time.
+                // (which for example disables inventory icon updates and prevents block breaking)
+                if (entity instanceof EntityPlayer) {
+                    iter.remove();
+                }
+            }
+
+            this.world.c((Collection) newList);
+            // CraftBukkit end
         }
 
     }
@@ -745,8 +810,8 @@
             while (iterator.hasNext()) {
                 Entity entity = (Entity) iterator.next();
 
-                if (entity.getBoundingBox().b(axisalignedbb) && (predicate == null || predicate.apply(entity))) {
-                    list.add(entity);
+                if (entity.getBoundingBox().b(axisalignedbb) && (predicate == null || predicate.apply((T) entity))) { // CraftBukkit - fix decompile error
+                    list.add((T) entity); // Fix decompile error
                 }
             }
         }
@@ -809,6 +874,29 @@
         } else {
             this.o();
             chunkgenerator.recreateStructures(this.locX, this.locZ);
+
+            // CraftBukkit start
+            BlockSand.instaFall = true;
+            Random random = new Random();
+            random.setSeed(world.getSeed());
+            long xRand = random.nextLong() / 2L * 2L + 1L;
+            long zRand = random.nextLong() / 2L * 2L + 1L;
+            random.setSeed((long) locX * xRand + (long) locZ * zRand ^ world.getSeed());
+
+            org.bukkit.World world = this.world.getWorld();
+            if (world != null) {
+                this.world.populating = true;
+                try {
+                    for (org.bukkit.generator.BlockPopulator populator : world.getPopulators()) {
+                        populator.populate(world, random, bukkitChunk);
+                    }
+                } finally {
+                    this.world.populating = false;
+                }
+            }
+            BlockSand.instaFall = false;
+            this.world.getServer().getPluginManager().callEvent(new org.bukkit.event.world.ChunkPopulateEvent(bukkitChunk));
+            // CraftBukkit end
             this.e();
         }