--- a/net/minecraft/server/PlayerChunkMap.java
+++ b/net/minecraft/server/PlayerChunkMap.java
@@ -37,6 +37,7 @@
 import org.apache.commons.lang3.mutable.MutableBoolean;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.bukkit.entity.Player; // CraftBukkit
 
 public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
 
@@ -58,7 +59,7 @@
     private final Mailbox<ChunkTaskQueueSorter.a<Runnable>> mailboxWorldGen;
     private final Mailbox<ChunkTaskQueueSorter.a<Runnable>> mailboxMain;
     public final WorldLoadListener worldLoadListener;
-    private final PlayerChunkMap.a u;
+    public final PlayerChunkMap.a u; // CraftBukkit - private -> public // PAIL chunkDistanceManager
     private final AtomicInteger v;
     private final DefinedStructureManager definedStructureManager;
     private final File x;
@@ -67,6 +68,31 @@
     private final Queue<Runnable> A;
     private int viewDistance;
 
+    // CraftBukkit start - recursion-safe executor for Chunk loadCallback() and unloadCallback()
+    public final CallbackExecutor callbackExecutor = new CallbackExecutor();
+    public static final class CallbackExecutor implements java.util.concurrent.Executor, Runnable {
+
+        private Runnable queued;
+
+        @Override
+        public void execute(Runnable runnable) {
+            if (queued != null) {
+                throw new IllegalStateException("Already queued");
+            }
+            queued = runnable;
+        }
+
+        @Override
+        public void run() {
+            Runnable task = queued;
+            queued = null;
+            if (task != null) {
+                task.run();
+            }
+        }
+    };
+    // CraftBukkit end
+
     public PlayerChunkMap(WorldServer worldserver, File file, DataFixer datafixer, DefinedStructureManager definedstructuremanager, Executor executor, IAsyncTaskHandler<Runnable> iasynctaskhandler, ILightAccess ilightaccess, ChunkGenerator<?> chunkgenerator, WorldLoadListener worldloadlistener, Supplier<WorldPersistentData> supplier, int i) {
         super(new File(worldserver.getWorldProvider().getDimensionManager().a(file), "region"), datafixer);
         this.visibleChunks = this.updatingChunks.clone();
@@ -184,9 +210,12 @@
 
         return completablefuture1.thenApply((list1) -> {
             List<IChunkAccess> list2 = Lists.newArrayList();
-            final int l1 = 0;
+            // CraftBukkit start - decompile error
+            int cnt = 0;
 
-            for (Iterator iterator = list1.iterator(); iterator.hasNext(); ++l1) {
+            for (Iterator iterator = list1.iterator(); iterator.hasNext(); ++cnt) {
+                final int l1 = cnt;
+                // CraftBukkit end
                 final Either<IChunkAccess, PlayerChunk.Failure> either = (Either) iterator.next();
                 Optional<IChunkAccess> optional = either.left();
 
@@ -284,7 +313,7 @@
             PlayerChunkMap.LOGGER.info("ThreadedAnvilChunkStorage ({}): All chunks are saved", this.x.getName());
         } else {
             this.visibleChunks.values().stream().filter(PlayerChunk::hasBeenLoaded).forEach((playerchunk) -> {
-                IChunkAccess ichunkaccess = (IChunkAccess) playerchunk.getChunkSave().getNow((Object) null);
+                IChunkAccess ichunkaccess = (IChunkAccess) playerchunk.getChunkSave().getNow(null); // CraftBukkit - decompile error
 
                 if (ichunkaccess instanceof ProtoChunkExtension || ichunkaccess instanceof Chunk) {
                     this.saveChunk(ichunkaccess);
@@ -295,7 +324,6 @@
         }
 
     }
-
     protected void unloadChunks(BooleanSupplier booleansupplier) {
         GameProfilerFiller gameprofilerfiller = this.world.getMethodProfiler();
 
@@ -334,7 +362,7 @@
 
     private void a(long i, PlayerChunk playerchunk) {
         CompletableFuture<IChunkAccess> completablefuture = playerchunk.getChunkSave();
-        Consumer consumer = (ichunkaccess) -> {
+        Consumer<IChunkAccess> consumer = (ichunkaccess) -> { // CraftBukkit - decompile error
             CompletableFuture<IChunkAccess> completablefuture1 = playerchunk.getChunkSave();
 
             if (completablefuture1 != completablefuture) {
@@ -483,7 +511,7 @@
                 return CompletableFuture.completedFuture(Either.right(playerchunk_failure));
             });
         }, (runnable) -> {
-            this.mailboxWorldGen.a((Object) ChunkTaskQueueSorter.a(playerchunk, runnable));
+            this.mailboxWorldGen.a(ChunkTaskQueueSorter.a(playerchunk, runnable)); // CraftBukkit - decompile error
         });
     }
 
@@ -564,7 +592,7 @@
             long i = playerchunk.i().pair();
 
             playerchunk.getClass();
-            mailbox.a((Object) ChunkTaskQueueSorter.a(runnable, i, playerchunk::getTicketLevel));
+            mailbox.a(ChunkTaskQueueSorter.a(runnable, i, playerchunk::getTicketLevel)); // CraftBukkit - decompile error
         });
     }
 
@@ -581,7 +609,7 @@
                 return Either.left(chunk);
             });
         }, (runnable) -> {
-            this.mailboxMain.a((Object) ChunkTaskQueueSorter.a(playerchunk, runnable));
+            this.mailboxMain.a(ChunkTaskQueueSorter.a(playerchunk, runnable)); // CraftBukkit - decompile error
         });
 
         completablefuture1.thenAcceptAsync((either) -> {
@@ -595,7 +623,7 @@
                 return Either.left(chunk);
             });
         }, (runnable) -> {
-            this.mailboxMain.a((Object) ChunkTaskQueueSorter.a(playerchunk, runnable));
+            this.mailboxMain.a(ChunkTaskQueueSorter.a(playerchunk, runnable)); // CraftBukkit - decompile error
         });
         return completablefuture1;
     }
@@ -609,7 +637,7 @@
                 return chunk;
             });
         }, (runnable) -> {
-            this.mailboxMain.a((Object) ChunkTaskQueueSorter.a(playerchunk, runnable));
+            this.mailboxMain.a(ChunkTaskQueueSorter.a(playerchunk, runnable)); // CraftBukkit - decompile error
         });
     }
 
@@ -724,7 +752,7 @@
     private NBTTagCompound readChunkData(ChunkCoordIntPair chunkcoordintpair) throws IOException {
         NBTTagCompound nbttagcompound = this.read(chunkcoordintpair);
 
-        return nbttagcompound == null ? null : this.getChunkData(this.world.getWorldProvider().getDimensionManager(), this.m, nbttagcompound);
+        return nbttagcompound == null ? null : this.getChunkData(this.world.getWorldProvider().getDimensionManager(), this.m, nbttagcompound, chunkcoordintpair, world); // CraftBukkit
     }
 
     boolean isOutsideOfRange(ChunkCoordIntPair chunkcoordintpair) {
@@ -1056,7 +1084,7 @@
         public final Set<EntityPlayer> trackedPlayers = Sets.newHashSet();
 
         public EntityTracker(Entity entity, int i, int j, boolean flag) {
-            this.trackerEntry = new EntityTrackerEntry(PlayerChunkMap.this.world, entity, j, flag, this::broadcast);
+            this.trackerEntry = new EntityTrackerEntry(PlayerChunkMap.this.world, entity, j, flag, this::broadcast, trackedPlayers); // CraftBukkit
             this.tracker = entity;
             this.trackingDistance = i;
             this.e = SectionPosition.a(entity);
@@ -1109,7 +1137,7 @@
 
         public void updatePlayer(EntityPlayer entityplayer) {
             if (entityplayer != this.tracker) {
-                Vec3D vec3d = (new Vec3D(entityplayer.locX, entityplayer.locY, entityplayer.locZ)).d(this.trackerEntry.b());
+                Vec3D vec3d = (new Vec3D(entityplayer.locX, entityplayer.locY, entityplayer.locZ)).d(this.tracker.ci()); // MC-155077, SPIGOT-5113 // PAIL getPositionVector
                 int i = Math.min(this.trackingDistance, (PlayerChunkMap.this.viewDistance - 1) * 16);
                 boolean flag = vec3d.x >= (double) (-i) && vec3d.x <= (double) i && vec3d.z >= (double) (-i) && vec3d.z <= (double) i && this.tracker.a(entityplayer);
 
@@ -1125,6 +1153,17 @@
                         }
                     }
 
+                    // CraftBukkit start - respect vanish API
+                    if (this.tracker instanceof EntityPlayer) {
+                        Player player = ((EntityPlayer) this.tracker).getBukkitEntity();
+                        if (!entityplayer.getBukkitEntity().canSee(player)) {
+                            flag1 = false;
+                        }
+                    }
+
+                    entityplayer.removeQueue.remove(Integer.valueOf(this.tracker.getId()));
+                    // CraftBukkit end
+
                     if (flag1 && this.trackedPlayers.add(entityplayer)) {
                         this.trackerEntry.b(entityplayer);
                     }