1 files changed, 100 insertions, 0 deletions
diff --git a/src/main/java/gq/malwarefight/nosession/relaunch/Relaunch.java b/src/main/java/gq/malwarefight/nosession/relaunch/Relaunch.java
new file mode 100644
index 0000000..55e907c
--- /dev/null
+++ b/src/main/java/gq/malwarefight/nosession/relaunch/Relaunch.java
@@ -0,0 +1,100 @@
+package gq.malwarefight.nosession.relaunch;
+
+import gq.malwarefight.nosession.tweaks.CleanupTweaker;
+import gq.malwarefight.nosession.utils.Utils;
+import net.minecraft.launchwrapper.Launch;
+import net.minecraftforge.fml.client.FMLClientHandler;
+import net.minecraftforge.fml.common.Loader;
+import net.minecraftforge.fml.common.ModAPIManager;
+import net.minecraftforge.fml.common.asm.ASMTransformerWrapper;
+import net.minecraftforge.fml.common.registry.ItemStackHolderInjector;
+import net.minecraftforge.fml.common.registry.ObjectHolderRegistry;
+import net.minecraftforge.fml.relauncher.FMLInjectionData;
+import net.minecraftforge.fml.relauncher.FMLLaunchHandler;
+
+import java.io.File;
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.ArrayList;
+
+public class Relaunch {
+    public static void relaunch(ArrayList<String> args, File gameDir, File assetsDir, String version) throws Exception {
+        resetSecurityManager();
+        setToNull(FMLLaunchHandler.class, "INSTANCE");
+        setToNull(Loader.class, "instance");
+        setToNull(ModAPIManager.class, "INSTANCE");
+        setToNull(ObjectHolderRegistry.class, "INSTANCE");
+        setToNull(ItemStackHolderInjector.class, "INSTANCE");
+        setToNull(FMLClientHandler.class, "INSTANCE");
+        setToNull(Loader.class, "injectedContainers");
+        Utils.setStaticValue(FMLInjectionData.class, "containers", new ArrayList<String>());
+        resetClass(ASMTransformerWrapper.class);
+        URLClassLoader originalClassLoader = (URLClassLoader) Launch.class.getClassLoader();
+        URL[] newURLS = new URL[originalClassLoader.getURLs().length + 1];
+        URLClassLoader lcl = new URLClassLoader(newURLS, originalClassLoader);
+        //noinspection unchecked
+        Class<Launch> innerLaunch = (Class<Launch>) Class.forName("net.minecraft.launchwrapper.Launch", false, lcl);
+        Method launch = innerLaunch.getDeclaredMethod("main", String[].class);
+        launch.invoke(null, (Object) constructArgs(args, gameDir, assetsDir, version));
+    }
+
+    public static String[] constructArgs(ArrayList<String> initial, File gameDir, File assetDir, String version) {
+        initial.add("--version");
+        initial.add(version);
+        initial.add("--gameDir");
+        initial.add(gameDir.getAbsolutePath());
+        initial.add("--assetsDir");
+        initial.add(assetDir.getAbsolutePath());
+        initial.add("--tweakClass");
+        initial.add("gq.malwarefight.nosession.tweaks.CleanupTweaker");
+        return initial.toArray(new String[0]);
+    }
+
+    public static void resetSecurityManager() throws IllegalAccessException, NoSuchMethodException, InvocationTargetException {
+        Method m = Class.class.getDeclaredMethod("getDeclaredFields0", boolean.class);
+        m.setAccessible(true);
+        Field[] fields = (Field[]) m.invoke(System.class, false);
+        for (Field field: fields) {
+            if (field.getType().equals(SecurityManager.class)) {
+                field.setAccessible(true);
+                field.set(null, null);
+            }
+        }
+    }
+
+
+    public static void resetClass(Class<?> cls) throws IllegalAccessException, NoSuchFieldException {
+        Field[] fields = cls.getDeclaredFields();
+        for (Field field: fields) {
+            if ((field.getModifiers() & Modifier.STATIC) != 0) {
+                setToNull(field);
+            }
+        }
+    }
+
+    public static void setToNull(Class<?> cls, String fieldname) throws NoSuchFieldException, IllegalAccessException {
+        Field f = cls.getDeclaredField(fieldname);
+        setToNull(f);
+    }
+
+    public static void setToNull(Field f) throws IllegalAccessException, NoSuchFieldException {
+        f.setAccessible(true);
+        if ((f.getModifiers() & Modifier.FINAL) != 0) { // if it is final
+            Field modifiers = Field.class.getDeclaredField("modifiers");
+            modifiers.setAccessible(true);
+            int value = modifiers.getInt(f);
+            value &= ~Modifier.FINAL;
+            modifiers.setInt(f, value);
+        }
+        if (f.getGenericType().equals(Boolean.TYPE)) {
+            f.set(null, false);
+        } else {
+            f.set(null, null);
+        }
+    }
+
+}