Patch ChunkProviderServer.loadedChunkHashMap in runtime, fix #1

src/main/java/kcauldron/KCauldonClassTransformer.java

@@ -0,0 +1,53 @@
+package kcauldron;
+
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.FieldVisitor;
+import org.objectweb.asm.MethodVisitor;
+
+import net.minecraft.launchwrapper.IClassTransformer;
+import static org.objectweb.asm.Opcodes.*;
+
+public class KCauldonClassTransformer implements IClassTransformer {
+	public static boolean DEV;
+
+	@Override
+	public byte[] transform(String name, String transformedName, byte[] basicClass) {
+		if ("net.minecraft.world.gen.ChunkProviderServer".equals(transformedName) || "net.minecraftforge.common.chunkio.ChunkIOProvider".equals(transformedName)) {
+			return patchChunkCall(basicClass);
+		}
+		return basicClass;
+	}
+	
+	private byte[] patchChunkCall(byte[] bytes) {
+		ClassReader reader = new ClassReader(bytes);
+		ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
+		reader.accept(new ClassVisitor(ASM5, writer) {
+			@Override
+			public FieldVisitor visitField(int access, String name,
+					String desc, String signature, Object value) {
+				if ("loadedChunkHashMap_vanilla".equals(name)) {
+					name = DEV ? "loadedChunkHashMap" : "field_73244_f";
+				}
+				return super.visitField(access, name, desc, signature, value);
+			}
+			
+			@Override
+			public MethodVisitor visitMethod(int access, String name,
+					String desc, String signature, String[] exceptions) {
+				return new MethodVisitor(api, super.visitMethod(access, name, desc, signature, exceptions)) {
+					@Override
+					public void visitFieldInsn(int opcode, String owner,
+							String name, String desc) {
+						if ("loadedChunkHashMap_vanilla".equals(name)) {
+							name = DEV ? "loadedChunkHashMap" : "field_73244_f";
+						}
+						super.visitFieldInsn(opcode, owner, name, desc);
+					}
+				};
+			}
+		}, 0);
+		return writer.toByteArray();
+	}
+}