Improve chunk unload queue to maintain some previous expectations

While the previous logic was logically correct, some CB API's before
would request a chunk without removing it from the unload queue.

While this is logically wrong, some plugins seem to be causing unload issues.

This change will make anything using that one API that use to not remove from
queue, no longer remove from queue.

Hopefully other activities on the server will touch the chunk if it REALLY is in use.

Spigot-Server-Patches/Add-World-Util-Methods.patch

@@ -15,12 +15,12 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
  
 +    // Paper start
 +    public Chunk getChunkIfLoaded(BlockPosition blockposition) {
-+        return ((ChunkProviderServer) this.chunkProvider).getChunkIfLoaded(blockposition.getX() >> 4, blockposition.getZ() >> 4);
++        return this.chunkProvider.getLoadedChunkAt(blockposition.getX() >> 4, blockposition.getZ() >> 4);
 +    }
 +    // Paper end
 +
      public Chunk getChunkIfLoaded(int x, int z) {
-         return ((ChunkProviderServer) this.chunkProvider).getChunkIfLoaded(x, z);
+         return ((ChunkProviderServer) this.chunkProvider).getLoadedChunkAtWithoutMarkingActive(x, z); // Paper - This is added by CB, and will not mark as active. Simply an alias
      }
 @@ -0,0 +0,0 @@ public abstract class World implements IBlockAccess {
          }

Spigot-Server-Patches/Optimize-Chunk-Unload-Queue.patch

@@ -69,19 +69,23 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 -        Chunk chunk = chunks.get(LongHash.toLong(x, z));
 -        return (chunk == null) ? getChunkAt(x, z) : chunk;
 +        return getChunkAt(x, z); // Paper
-     }
++    }
- 
++
 +    // Paper start
 +    public Chunk getLoadedChunkAtWithoutMarkingActive(int i, int j) {
 +        return chunks.get(LongHash.toLong(i, j));
-+    }
-+    // Paper end
-+
-     public Chunk getChunkIfLoaded(int x, int z) {
--        return chunks.get(LongHash.toLong(x, z));
-+        return getLoadedChunkAt(x, z); // Paper - Bukkit has a duplicate method now.
      }
  
+-    public Chunk getChunkIfLoaded(int x, int z) {
+-        return chunks.get(LongHash.toLong(x, z));
++    // getChunkIfLoaded -> getChunkIfActive
++    // this is only used by CraftBukkit now, and plugins shouldnt mark things active
++    public Chunk getChunkIfActive(int x, int z) {
++        Chunk chunk = chunks.get(LongHash.toLong(x, z));
++        return (chunk != null && chunk.isChunkActive) ? chunk : null;
+     }
++    // Paper end
+ 
      public Chunk getLoadedChunkAt(int i, int j) {
          Chunk chunk = chunks.get(LongHash.toLong(i, j)); // CraftBukkit
  
@@ -174,10 +178,40 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
              {
                  i += server.getChunkAt( x, z ).entityCount.get( oClass );
              }
+diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/World.java
++++ b/src/main/java/net/minecraft/server/World.java
+@@ -0,0 +0,0 @@ public abstract class World implements IBlockAccess {
+     }
+ 
+     public Chunk getChunkIfLoaded(int x, int z) {
+-        return ((ChunkProviderServer) this.chunkProvider).getChunkIfLoaded(x, z);
++        return ((ChunkProviderServer) this.chunkProvider).getLoadedChunkAtWithoutMarkingActive(x, z); // Paper - This is added by CB, and will not mark as active. Simply an alias
+     }
+ 
++    // Paper start
++    public Chunk getChunkIfActive(int x, int z) {
++        return ((ChunkProviderServer) this.chunkProvider).getChunkIfActive(x, z);
++    }
++    // Paper end
++
+     protected World(IDataManager idatamanager, WorldData worlddata, WorldProvider worldprovider, MethodProfiler methodprofiler, boolean flag, ChunkGenerator gen, org.bukkit.World.Environment env) {
+         this.spigotConfig = new org.spigotmc.SpigotWorldConfig( worlddata.getName() ); // Spigot
+         this.paperConfig = new com.destroystokyo.paper.PaperWorldConfig(worlddata.getName(), this.spigotConfig); // Paper
 diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
 +++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+@@ -0,0 +0,0 @@ public class CraftWorld implements World {
+         }
+ 
+         // Paper start - Don't create a chunk just to unload it
+-        net.minecraft.server.Chunk chunk = world.getChunkProviderServer().getChunkIfLoaded(x, z);
++        net.minecraft.server.Chunk chunk = world.getChunkProviderServer().getChunkIfActive(x, z); // Paper
+         if (chunk == null) {
+             return false;
+         }
 @@ -0,0 +0,0 @@ public class CraftWorld implements World {
                      continue;
                  }
@@ -227,4 +261,17 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
                  if (neighbor != null) {
                      neighbor.setNeighborLoaded(-x, -z);
                      chunk.setNeighborLoaded(x, z);
+diff --git a/src/main/java/org/spigotmc/ActivationRange.java b/src/main/java/org/spigotmc/ActivationRange.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/spigotmc/ActivationRange.java
++++ b/src/main/java/org/spigotmc/ActivationRange.java
+@@ -0,0 +0,0 @@ public class ActivationRange
+         int x = MathHelper.floor( entity.locX );
+         int z = MathHelper.floor( entity.locZ );
+         // Make sure not on edge of unloaded chunk
+-        Chunk chunk = entity.world.getChunkIfLoaded( x >> 4, z >> 4 );
++        Chunk chunk = entity.world.getChunkIfActive( x >> 4, z >> 4 ); // Paper
+         if ( isActive && !( chunk != null && chunk.areNeighborsLoaded( 1 ) ) )
+         {
+             isActive = false;
 --