Fixed ChunkDataEvent.Save being fired with a null world if chunk isn't fully generated when unloaded. (#6628)

patches/minecraft/net/minecraft/world/server/ChunkManager.java.patch

@@ -36,7 +36,7 @@
  
              this.field_219255_i.func_217381_Z().func_230035_c_("chunkSave");
              CompoundNBT compoundnbt1 = ChunkSerializer.func_222645_a(this.field_219255_i, p_219229_1_);
-+            net.minecraftforge.common.MinecraftForge.EVENT_BUS.post(new net.minecraftforge.event.world.ChunkDataEvent.Save(p_219229_1_, compoundnbt1));
++            net.minecraftforge.common.MinecraftForge.EVENT_BUS.post(new net.minecraftforge.event.world.ChunkDataEvent.Save(p_219229_1_, p_219229_1_.getWorldForge() != null ? p_219229_1_.getWorldForge() : this.field_219255_i, compoundnbt1));
              this.func_219100_a(chunkpos, compoundnbt1);
              return true;
           } catch (Exception exception) {

src/main/java/net/minecraftforge/event/world/ChunkDataEvent.java

@@ -20,6 +20,7 @@
 package net.minecraftforge.event.world;
 
 import net.minecraft.nbt.CompoundNBT;
+import net.minecraft.world.IWorld;
 import net.minecraft.world.World;
 import net.minecraft.world.chunk.Chunk;
 import net.minecraft.world.chunk.ChunkStatus;
@@ -47,6 +48,12 @@ public class ChunkDataEvent extends ChunkEvent
         this.data = data;
     }
 
+    public ChunkDataEvent(IChunk chunk, IWorld world, CompoundNBT data)
+    {
+        super(chunk, world);
+        this.data = data;
+    }
+
     public CompoundNBT getData()
     {
         return data;
@@ -92,9 +99,15 @@ public class ChunkDataEvent extends ChunkEvent
      **/
     public static class Save extends ChunkDataEvent
     {
+        @Deprecated // remove in 1.16
         public Save(IChunk chunk, CompoundNBT data)
         {
             super(chunk, data);
         }
+
+        public Save(IChunk chunk, IWorld world, CompoundNBT data)
+        {
+            super(chunk, world, data);
+        }
     }
 }

src/main/java/net/minecraftforge/event/world/ChunkEvent.java

@@ -19,6 +19,7 @@
 
 package net.minecraftforge.event.world;
 
+import net.minecraft.world.IWorld;
 import net.minecraft.world.chunk.IChunk;
 import net.minecraftforge.common.MinecraftForge;
 
@@ -41,6 +42,12 @@ public class ChunkEvent extends WorldEvent
         this.chunk = chunk;
     }
 
+    public ChunkEvent(IChunk chunk, IWorld world)
+    {
+        super(world);
+        this.chunk = chunk;
+    }
+
     public IChunk getChunk()
     {
         return chunk;

src/test/java/net/minecraftforge/debug/world/ChunkDataEventSaveNullWorldTest.java

@@ -0,0 +1,23 @@
+package net.minecraftforge.debug.world;
+
+import net.minecraftforge.event.world.ChunkDataEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+@Mod(ChunkDataEventSaveNullWorldTest.MODID)
+@Mod.EventBusSubscriber
+public class ChunkDataEventSaveNullWorldTest {
+  static final String MODID = "chunk_data_event_save_null_world_test";
+  private static final Logger LOGGER = LogManager.getLogger(MODID);
+
+  @SubscribeEvent
+  public static void onChunkSave(final ChunkDataEvent.Save event)
+  {
+    if(event.getWorld() == null)
+    {
+      LOGGER.info("Chunk at {} had null world", event.getChunk().getPos());
+    }
+  }
+}

src/test/resources/META-INF/mods.toml

@@ -63,6 +63,8 @@ loaderVersion="[28,)"
     modId="global_loot_test"
 [[mods]]
     modId="custom_plant_type_test"
+[[mods]]
+    modId="chunk_data_event_save_null_world_test"
 [[dependencies.global_loot_test]]
     modId="forge"
     mandatory=true