fix structure upgrading

CHANGELOG.md

@@ -5,7 +5,4 @@ Make sure to clear this after each release
 Put changelog here:
 
 -----------------
-- Fixed FrozenLib's capes causing severe performance issues when switching dimensions or respawning.
-- Fixed `NbtFileUtils` creating a directory instead of a file.
-- Added the `structure_upgrade` command, only accessible in development environments.
-  - This takes a string for the `namespace` parameter, and will grab all structure pieces under the given namespace then save them to `run/upgraded_structure,` upgraded to the latest DataVersion.
+- Fixed structure upgrading not saving anything.

gradle.properties

@@ -15,7 +15,7 @@
 	min_loader_version=0.16.0
 
 # Mod Properties
-	mod_version = 1.9.3
+	mod_version = 1.9.4
 	maven_group = net.frozenblock
 	archives_base_name = FrozenLib
 

src/main/java/net/frozenblock/lib/worldgen/structure/impl/StructureUpgradeCommand.java

@@ -26,11 +26,17 @@
 import net.minecraft.commands.CommandSourceStack;
 import net.minecraft.commands.Commands;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtAccounter;
+import net.minecraft.nbt.NbtIo;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.packs.resources.ResourceManager;
+import net.minecraft.util.FastBufferedInputStream;
+import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplate;
 import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemplateManager;
 import org.jetbrains.annotations.NotNull;
+import java.io.IOException;
+import java.io.InputStream;
 import java.nio.file.Path;
 import java.util.Map;
 import java.util.Set;
@@ -65,7 +71,19 @@ private static int upgradeAndExportPieces(@NotNull CommandSourceStack source, St
 		Map<ResourceLocation, CompoundTag> savedTemplates = new Object2ObjectLinkedOpenHashMap<>();
 
 		foundPieces.forEach((resourceLocation) -> {
-			savedTemplates.put(resourceLocation, structureTemplateManager.getOrCreate(resourceLocation).save(new CompoundTag()));
+			try {
+				InputStream inputStream = resourceManager.getResourceOrThrow(resourceLocation).open();
+				InputStream inputStream2 = new FastBufferedInputStream(inputStream);
+				CompoundTag compoundTag = NbtIo.readCompressed(inputStream2, NbtAccounter.unlimitedHeap());
+				StructureTemplate structureTemplate = structureTemplateManager.readStructure(compoundTag);
+
+				inputStream2.close();
+				inputStream.close();
+
+				savedTemplates.put(resourceLocation, structureTemplate.save(new CompoundTag()));
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
 		});
 
 		Path outputPath = source.getServer().getServerDirectory()