PaperMC/nms-patches/ChunkMap.patch

--- a/net/minecraft/server/ChunkMap.java
+++ b/net/minecraft/server/ChunkMap.java
@@ -31,6 +31,54 @@
             }
         }
 
+        org.bukkit.Server server = chunk.world.getServer();
+        if (server != null) {
+            /*
+             * If it's a new world, the first few chunks are generated inside
+             * the World constructor. We can't reliably alter that, so we have
+             * no way of creating a CraftWorld/CraftServer at that point.
+             */
+            server.getPluginManager().callEvent(new org.bukkit.event.world.ChunkLoadEvent(chunk.bukkitChunk, chunk.newChunk));
+        }
+
+        // Update neighbor counts
+        for (int x = -2; x < 3; x++) {
+            for (int z = -2; z < 3; z++) {
+                if (x == 0 && z == 0) {
+                    continue;
+                }
+
+                Chunk neighbor = this.get(ChunkCoordIntPair.a(chunkcoordintpair.x + x, chunkcoordintpair.z + z));
+                if (neighbor != null) {
+                    neighbor.setNeighborLoaded(-x, -z);
+                    chunk.setNeighborLoaded(x, z);
+                }
+            }
+        }
+
+        if (chunk.newChunk) {
+            BlockSand.instaFall = true;
+            java.util.Random random = new java.util.Random();
+            random.setSeed(chunk.world.getSeed());
+            long xRand = random.nextLong() / 2L * 2L + 1L;
+            long zRand = random.nextLong() / 2L * 2L + 1L;
+            random.setSeed((long) chunk.locX * xRand + (long) chunk.locZ * zRand ^ chunk.world.getSeed());
+
+            org.bukkit.World world = chunk.world.getWorld();
+            if (world != null) {
+                chunk.world.populating = true;
+                try {
+                    for (org.bukkit.generator.BlockPopulator populator : world.getPopulators()) {
+                        populator.populate(world, random, chunk.bukkitChunk);
+                    }
+                } finally {
+                    chunk.world.populating = false;
+                }
+            }
+            BlockSand.instaFall = false;
+            chunk.world.getServer().getPluginManager().callEvent(new org.bukkit.event.world.ChunkPopulateEvent(chunk.bukkitChunk));
+        }
+
         return chunk1;
     }
 
@@ -69,23 +117,25 @@
         throw new RuntimeException("Not yet implemented");
     }
 
-    public Object remove(Object object) {
+    // CraftBukkit start - decompile errors
+    public Chunk remove(Object object) {
         return this.a(object);
     }
 
-    public Object remove(long i) {
+    public Chunk remove(long i) {
         return this.a(i);
     }
 
-    public Object put(Long olong, Object object) {
+    public Chunk put(Long olong, Chunk object) {
         return this.a(olong, (Chunk) object);
     }
 
-    public Object put(long i, Object object) {
+    public Chunk put(long i, Chunk object) {
         return this.a(i, (Chunk) object);
     }
 
-    public Object put(Object object, Object object1) {
+    public Object put(Object object, Chunk object1) {
         return this.a((Long) object, (Chunk) object1);
     }
+    // CraftBukkit end
 }