Fix #454

If a chunk is loaded through ChunkSchedulingPatch, but no ChunkLoadEvent is called that enables the chunk before a world save, the region file could be unloaded again, leading to "Block chunk is not loaded" exceptions when world generation tries to place blocks. (Notably, this only interfered with world generation because WorldDataManager loads the chunk on ChunkLoadEvent)

nova/src/main/kotlin/xyz/xenondevs/nova/world/format/RegionFile.kt

@@ -15,12 +15,12 @@ internal class RegionFile(
     chunks: Array<RegionChunk>
 ) : RegionizedFile<RegionChunk>(MAGIC, VERSION, file, world, regionX, regionZ, chunks) {
 
-    fun isAnyChunkEnabled(): Boolean {
+    fun isInactive(): Boolean {
         for (chunk in chunks) {
-            if (chunk.isEnabled)
-                return true
+            if (chunk.isEnabled || !chunk.hasBeenEnabled)
+                return false
         }
-        return false
+        return true
     }
 
     companion object : RegionizedFileReader<RegionChunk, RegionFile>(

nova/src/main/kotlin/xyz/xenondevs/nova/world/format/WorldDataStorage.kt

@@ -113,7 +113,7 @@ internal class WorldDataStorage(val world: World) {
                     regionFile.save()
 
                     // unload unused region files
-                    if (unload && !regionFile.isAnyChunkEnabled())
+                    if (unload && regionFile.isInactive())
                         blockRegionFiles -= rid
                 }
             }

nova/src/main/kotlin/xyz/xenondevs/nova/world/format/chunk/RegionChunk.kt

@@ -46,6 +46,10 @@ internal class RegionChunk(
     @Volatile
     var isEnabled = false
         private set
+    @Volatile
+    var hasBeenEnabled = false
+        private set
+
     private var tickingAllowed = false
     private var isTicking = false
 
@@ -353,6 +357,7 @@ internal class RegionChunk(
                 }
             }
 
+            hasBeenEnabled = true
             isEnabled = true
         }
     }