Патчить апдейтер, а не только лаунчер

Вендорный updater.exe перекачивает app.jar, и патч лаунчера после этого стирался. Теперь патчится и сам апдейтер: в его payload (jar, пришитый к PE-заглушке Launch4j после offset 65024) вставляются два хука. - UpdaterGui.runLauncher -> beforeLauncher: перепатчить app.jar перед стартом лаунчера, если апдейтер достал его из своего кэша. - DownloadEngine.findFilesToDownload -> filterUpdates: убрать app.jar из скачивания, но только если хеш манифеста равен baseSha256 из .rsx-patched. Другой хеш означает настоящее обновление, и файл качается как обычно. Хук сделан обёрткой вокруг findFilesToDownload, а не правкой call site: у invokespecial получатель лежит под аргументами, и замена вызова ломала стек. Ещё лаунчер при старте чинит свой updater.exe (jb -> l качает "updater.exe"), из-за чего хук жил ровно один запуск. Этот путь закрыт третьим guard. Ещё: - .rsx-patched теперь пишет сам патчер: baseSha256 нужен фильтру, чтобы отличать наш патч от настоящего обновления. - patchupdater идемпотентен и берёт pristine-копию из updater.exe.orig. - Перед записью payload проверяется загрузкой классов. - Установщик патчит апдейтер, а uninstall откатывает и его. - Маркер и log больше не прибиты к %APPDATA%\kjstudio: папки выводятся из расположения апдейтера. Проверено на живой установке два запуска подряд: хук выживает, app.jar остаётся пропатченным, updater качает 0 файлов.
2026-10-17 01:48:24 +03:00
parent ba6cfe50fc
commit 9f43d35f44
14 changed files with 1374 additions and 535 deletions
@@ -20,8 +20,8 @@ desktop.ini
 __pycache__/
 *.pyc

-# Nothing machine-specific belongs here: the profile is generated by
-# prepare-build.cmd on the machine that has the game installed.
-*.rsxp
+# profiles/latest.rsxp IS tracked: it is the mapping for the current vendor
+# build, and without it mods cannot load. Regenerate it with prepare-build.cmd
+# when the game updates.
 hs_err_pid*.log
 replay_pid*.log
@@ -0,0 +1,17 @@
+# Authors
+
+* **SashegDev** — автор и мейнтейнер (`gdsasheg@gmail.com`)
+
+## Third-party components
+
+* **ASM** (`third_party/asm`) — BSD 3-Clause, <https://asm.ow2.io/license.html>.
+  Вендорится, чтобы патчер запускался без Gradle и без сети.
+* **org.json** — используется внутри `updater.jar` вендора, в наш код не входит.
+
+## What this project is not
+
+RustexRemake, KJST Launcher и его апдейтер — сторонние продукты. Здесь нет ни
+их кода, ни их файлов, кроме готовых патчей, которые инструмент применяет на
+машине пользователя. Правки лаунчера и апдейтера обратимы: оригиналы
+сохраняются как `app.jar.orig` и `updater.exe.orig`, а `uninstall.cmd`
+возвращает всё на место.
@@ -1,6 +1,6 @@
 MIT License

-Copyright (c) 2026 rsx-modloader contributors
+Copyright (c) 2026 SashegDev

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -52,7 +52,7 @@ third_party\asm\       ASM (BSD-3), зашит внутрь rsx-launcher-patch.j

 ## Патч лаунчера

-Лаунчер — сторонний продукт, и у него две особенности, которые мешают:
+Лаунчер — сторонний продукт, и у него три особенности, которые мешают:

 * **Гонка за состоянием кнопки.** `xa.run()` вызывает `ha.y()` (ставит `PLAY`),
  а `fa.loadedWeb()` позже ставит `ERROR`. Состояния — это индексы кнопок в
@@ -64,10 +64,42 @@ third_party\asm\       ASM (BSD-3), зашит внутрь rsx-launcher-patch.j
  `ha` (хеш рабочего jar, отсюда «обновление найдено, перезапустите лаунчер»).
  Оба закрыты через `rsx.Patch`, который действует только на файл с именем
  `app.jar` и только при наличии маркера `.rsx-patched`.
+* **Ремонт своего апдейтера.** При старте лаунчер проверяет хеш `updater.exe`
+  и, не найдя вендорскую сборку, скачивает чистую копию поверх
+  (`jb` → `l.ALLATORIxDEMO()` → «updater.exe»). Метод `jb` заменён на
+  `rsx.Patch.skipUpdaterRepair()`.

 Возврат к обычному поведению: удалить `.rsx-patched` или запустить лаунчер с
 `-Drsx.allowLauncherUpdate=true`.

+## Патч апдейтера
+
+`updater.exe` — это PE-заглушка Launch4j, к которой обычным zip просто пришит
+jar (payload начинается с offset 65024 и идёт до EOF). Заглушка запускает jar из
+себя, поэтому патчить надо именно хвост, а PE-заголовок не трогаем.
+
+В payload вставляются два хука:
+
+* `UpdaterGui.runLauncher(Z)V` → `rsx.UpdaterHook.beforeLauncher(...)` —
+  перед запуском лаунчера `app.jar` патчится заново, если он оказался
+  вендорским (апдейтер достаёт его из своего локального кэша даже когда скачивать
+  нечего).
+* `DownloadEngine.findFilesToDownload` → `rsx.UpdaterHook.filterUpdates(...)` —
+  `app.jar` убирается из списка на скачивание, **только** если хеш в манифесте
+  совпадает с `baseSha256` из `.rsx-patched`. Хеш другой — значит настоящее
+  обновление, и файл скачивается как обычно.
+
+`baseSha256` — это хеш нетронутого `app.jar`; патчер пишет его в `.rsx-patched`
+сам, до того как перезаписать файл. При настоящем обновлении маркер
+перезаписывается новым значением.
+
+Хук идемпотентен: повторный `patchupdater` берёт pristine-копию из
+`updater.exe.orig`, а если `updater.exe` заменил вендор — обновляет бэкап.
+Перед записью собранный jar проверяется загрузкой классов, так что битый патч
+никогда не попадёт на диск.
+
+Лог: `%APPDATA%\kjstudio\rsx-launcher\updater-patch.log`.
+
 ## Конфиг лаунчера — осторожно

 `launcher_config.properties` — это properties-файл: слэш экранирует следующий
@@ -1,19 +0,0 @@
-23:54:04.418 [INFO] --- rsx bridge log opened: G:\rsx-modloader\bridge\src\test\python\run\rsx\bridge.log
-23:54:04.420 [INFO] rsx bridge starting (home=G:\rsx-modloader\bridge\src\test\python\run\bridge)
-23:54:04.436 [INFO] profile 8446af0b5e805725 from latest.rsxp (named 1/1)
-23:54:04.436 [INFO] loader anchor: net.rustexremake.loader.RemoteClassLoader (unmapped)
-23:54:04.466 [INFO] build verified: game.jar sha256 ok
-23:54:04.466 [INFO] A2 applied: -Djoml.fastmath=true (class wsygzaib)
-23:54:04.474 [INFO] game class loader: sun.misc.Launcher$AppClassLoader@349885916
-23:54:04.985 [INFO] client is up, loader: sun.misc.Launcher$AppClassLoader@349885916
-23:54:05.007 [INFO] A6 applied: telemetry timers replaced in 1 object(s), 1 found
-23:54:05.009 [INFO] found 1 mod jar(s) in G:\rsx-modloader\bridge\src\test\python\run\mods
-23:54:05.063 [INFO] ExampleMod: loaded on build 8446af0b5e805725
-23:54:05.063 [INFO] ExampleMod: Minecraft is net.minecraft.client.Minecraft -> wwk
-23:54:05.065 [INFO] mod loaded: example-mod.jar (example.ExampleMod)
-23:54:05.065 [INFO] ready: 1 mod(s) loaded
-23:54:06.995 [INFO] ExampleMod tick 1 client=true player=PLAYER world=WORLD
-23:54:07.197 [INFO] ExampleMod tick 2 client=true player=PLAYER world=WORLD
-23:54:07.399 [INFO] ExampleMod tick 3 client=true player=PLAYER world=WORLD
-23:54:07.615 [INFO] ExampleMod tick 4 client=true player=PLAYER world=WORLD
-23:54:07.816 [INFO] ExampleMod tick 5 client=true player=PLAYER world=WORLD
@@ -30,7 +30,8 @@ REPO = os.path.dirname(os.path.dirname(os.path.dirname(
 BRIDGE_JAR = os.path.join(REPO, "dist", "rsx-bridge.jar")
 SRC = os.path.join(os.path.dirname(HERE), "fakeclient")
 MOD_SRC = os.path.join(os.path.dirname(HERE), "mod")
-RUN = os.path.join(HERE, "run")
+# work outside the source tree: the stand writes jars and logs
+RUN = os.path.join(REPO, "build", "testrun")


 def sh(*args, **kw):
@@ -3,6 +3,7 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.util.Arrays;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
@@ -22,6 +23,7 @@ import org.objectweb.asm.tree.AbstractInsnNode;
 import org.objectweb.asm.tree.ClassNode;
 import org.objectweb.asm.tree.FieldInsnNode;
 import org.objectweb.asm.tree.InsnList;
+import org.objectweb.asm.tree.InsnNode;
 import org.objectweb.asm.tree.JumpInsnNode;
 import org.objectweb.asm.tree.LdcInsnNode;
 import org.objectweb.asm.tree.MethodInsnNode;
@@ -38,9 +40,19 @@ import org.objectweb.asm.tree.VarInsnNode;
 public final class LauncherPatch {

    private static final String TARGET_CLASS = "fa";
-private static final String UPDATER_CLASS = "sb";
+    private static final String UPDATER_CLASS = "sb";
    private static final String SELF_UPDATE_CLASS = "ha";
    private static final String GUARD = "rsx/Patch";
+    private static final String UPDATER_GUI = "koptokop/updater/gui/UpdaterGui";
+    private static final String UPDATER_LAUNCHER =
+            "koptokop/updater/gui/LauncherUpdater";
+    private static final String UPDATER_ENGINE = "download/engine/DownloadEngine";
+    // jb re-downloads updater.exe whenever its hash is not the vendor build,
+    // which would silently undo the hook installed in updater.exe
+    private static final String UPDATER_REPAIR_CLASS = "jb";
+    private static final String UPDATER_REPAIR_METHOD = "ALLATORIxDEMO";
+    private static final String UPDATER_REPAIR_DESC = "(Ljava/lang/String;)V";
+    private static final String HOOK = "rsx/UpdaterHook";
    private static final String PLAY_ID = "clickPlay";
    private static final String CHOICE = "rsx/Choice";
    private static final String CHOICE_RESOURCE = "rsx/env-field.txt";
@@ -84,6 +96,10 @@ public static void main(String[] args) throws Exception {
            setProp(jar, args[2], args[3]);
            return;
        }
+        if ("patchupdater".equals(mode)) {
+            patchUpdater(jar, Paths.get(args[2]));
+            return;
+        }
        // patch <app.jar> <modloaderHome> [envFieldSpec]
        Path home = Paths.get(args[2]);
        String envMeta = args.length > 3 ? args[3].replace(",", "\n") : "wa\nALLATORIxDEMO";
@@ -374,9 +390,9 @@ private static boolean check(Path jarPath) throws Exception {
        }
 boolean ok = true;
        for (String name : new String[] {TARGET_CLASS, UPDATER_CLASS,
-                SELF_UPDATE_CLASS, "rsx.Patch"}) {
+                SELF_UPDATE_CLASS, UPDATER_REPAIR_CLASS, "rsx.Patch"}) {
            try {
-                Class.forName(name, true, loader);
+                Class.forName(name.replace('/', '.'), true, loader);
                System.out.println("  " + name + " verifies");
            } catch (Throwable t) {
                Throwable cause = t;
@@ -462,6 +478,7 @@ private static void patch(Path jarPath, Path home, String envMeta)
        if (alreadyPatched) {
            System.out.println("already patched, nothing to do");
            jar.close();
+            ensureMarker(jarPath);
            return;
        }
        if (play == null) {
@@ -531,6 +548,38 @@ injectPlayChoice(play);
        ha.accept(haWriter);
        byte[] haBytes = haWriter.toByteArray();

+        // Third guard: the launcher repairs updater.exe on every start. Left
+        // alone it replaces our hooked updater with the vendor build, which
+        // brings back the "update wipes the patch" problem one launch later.
+        ClassNode jb = readClass(jar, UPDATER_REPAIR_CLASS);
+        boolean repairBlocked = false;
+        for (MethodNode m : jb.methods) {
+            if (!m.name.equals(UPDATER_REPAIR_METHOD)
+                    || !m.desc.equals(UPDATER_REPAIR_DESC)
+                    || hasRepairGuard(m)) {
+                continue;
+            }
+            m.instructions.clear();
+            m.tryCatchBlocks.clear();
+            m.localVariables.clear();
+            m.instructions.add(new MethodInsnNode(Opcodes.INVOKESTATIC, GUARD,
+                    "skipUpdaterRepair", "()V", false));
+            m.instructions.add(new InsnNode(Opcodes.RETURN));
+            m.maxStack = 0;
+            m.maxLocals = 1;
+            repairBlocked = true;
+            System.out.println("blocked " + UPDATER_REPAIR_CLASS + "."
+                    + m.name + m.desc + " from restoring updater.exe");
+            break;
+        }
+        if (!repairBlocked) {
+            System.out.println("WARNING: " + UPDATER_REPAIR_CLASS + "."
+                    + UPDATER_REPAIR_METHOD + " not found or already blocked");
+        }
+        ClassWriter jbWriter = new ClassWriter(ClassWriter.COMPUTE_MAXS);
+        jb.accept(jbWriter);
+        byte[] jbBytes = jbWriter.toByteArray();
+
 ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
        cls.accept(writer);
        writer.getClass();
@@ -544,6 +593,9 @@ ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
            Files.copy(jarPath, backup, StandardCopyOption.COPY_ATTRIBUTES);
            System.out.println("backup: " + backup);
        }
+        // the hash the vendor manifest advertises for the untouched jar; the
+        // updater hook uses it to tell "our patch" from "a real update"
+        String baseHash = sha256(jarPath);

        Path tmp = jarPath.resolveSibling(jarPath.getFileName() + ".new");
        OutputStream out = Files.newOutputStream(tmp);
@@ -555,7 +607,8 @@ ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS);
 String name = entry.getName();
                if (name.equals(TARGET_CLASS + ".class")
                        || name.equals(UPDATER_CLASS + ".class")
-                        || name.equals(SELF_UPDATE_CLASS + ".class")) {
+                        || name.equals(SELF_UPDATE_CLASS + ".class")
+                || name.equals(UPDATER_REPAIR_CLASS + ".class")) {
                    continue;
                }
                if (name.startsWith("rsx/") || name.equals(CHOICE_RESOURCE)) {
@@ -583,35 +636,13 @@ outJar.putNextEntry(new JarEntry(UPDATER_CLASS + ".class"));
            outJar.write(haBytes);
            outJar.closeEntry();

-// rsx/ classes come from this patcher's own jar, which keeps the
-            // installer free of build directories: Choice$1 and Choice$2 have
-            // to travel along or loading Choice fails with NoClassDefFoundError
-            Path self = Paths.get(LauncherPatch.class.getProtectionDomain()
-                    .getCodeSource().getLocation().toURI());
-            int copied = 0;
-            try (JarFile own = new JarFile(self.toFile())) {
-                Enumeration<JarEntry> mine = own.entries();
-                while (mine.hasMoreElements()) {
-                    JarEntry e = mine.nextElement();
-                    if (!e.getName().startsWith("rsx/") || e.isDirectory()) {
-                        continue;
-                    }
-                    outJar.putNextEntry(new JarEntry(e.getName()));
-                    InputStream in = own.getInputStream(e);
-                    try {
-                        copyStream(in, outJar);
-                    } finally {
-                        in.close();
-                    }
-                    outJar.closeEntry();
-                    copied++;
-                    System.out.println("  + " + e.getName());
-                }
-            }
-            if (copied == 0) {
-                throw new IllegalStateException(
-                        "no rsx/ classes inside the patcher jar");
-            }
+            outJar.putNextEntry(new JarEntry(UPDATER_REPAIR_CLASS + ".class"));
+            outJar.write(jbBytes);
+            outJar.closeEntry();
+
+            // rsx/ classes travel with the patcher; Choice$1 and Choice$2 have
+            // to come along or loading Choice fails with NoClassDefFoundError
+            addHookClasses(outJar);

            outJar.putNextEntry(new JarEntry(CHOICE_RESOURCE));
            outJar.write(envBytes);
@@ -638,6 +669,7 @@ outJar.putNextEntry(new JarEntry(UPDATER_CLASS + ".class"));
                + Files.size(jarPath) + " bytes)");

        String hash = sha256(jarPath);
+        writeMarker(jarPath, baseHash, hash);
        Path json = jarPath.resolveSibling("app.jar.json");
        if (Files.isRegularFile(json)) {
            Files.write(json, ("{\"hash\": \"" + hash + "\"}")
@@ -668,8 +700,332 @@ private static boolean hasChoiceCall(MethodNode m) {
        return false;
    }

+/**
+ * Rebuild updater.exe with a hooked jar inside.
+ *
+ * The exe is a small PE stub (its .rsrc ends exactly where the payload starts)
+ * with updater.jar appended to the end. Nothing in the stub records the payload
+ * offset or length - it runs "java -jar <itself>" and Java tolerates a zip that
+ * has a prefix - so the tail can simply be replaced with a new jar.
+ *
+ * usage: patchupdater <updater.exe> <modloaderHome>
+ */
+    private static void patchUpdater(Path exe, Path home) throws Exception {
+        byte[] all = Files.readAllBytes(exe);
+        int start = zipStart(all);
+        if (start < 0) {
+            throw new IllegalStateException(
+                    "no zip payload found inside " + exe);
+        }
+        byte[] currentJar = java.util.Arrays.copyOfRange(all, start, all.length);
+
+        // Re-patching an already hooked exe would add a second wrapper, so work
+        // from a pristine copy. Whether this exe is ours is decided by the hook
+        // class inside it, not by comparing bytes: our patch always differs from
+        // the backup, and so does a vendor update.
+        Path backup = exe.resolveSibling(exe.getFileName() + ".orig");
+        byte[] originalJar = currentJar;
+        boolean currentHooked = hasHookClass(currentJar);
+        byte[] backupJar = payloadOf(backup);
+        boolean backupHooked = backupJar != null && hasHookClass(backupJar);
+        if (currentHooked && !backupHooked && backupJar != null) {
+            originalJar = backupJar;
+            System.out.println("  re-patching from the pristine backup");
+        } else if (!currentHooked && backupHooked) {
+            Files.copy(exe, backup, StandardCopyOption.REPLACE_EXISTING);
+            System.out.println("  updater was replaced by the vendor, "
+                    + "backup refreshed");
+        } else if (backupJar == null) {
+            Files.copy(exe, backup, StandardCopyOption.COPY_ATTRIBUTES);
+            System.out.println("  backup: " + backup);
+        }
+        if (hasHookClass(originalJar)) {
+            System.out.println("updater is already hooked, nothing to do");
+            return;
+        }
+
+        Path tmpJar = Files.createTempFile("updater-patched", ".jar");
+        try {
+            Files.write(tmpJar, buildHookedUpdater(originalJar));
+            String keep = System.getenv("RSX_KEEP_TMP");
+            if (keep != null && !keep.isEmpty()) {
+                Path kept = Paths.get(keep);
+                Files.copy(tmpJar, kept, StandardCopyOption.REPLACE_EXISTING);
+                System.out.println("  kept: " + kept + " ("
+                        + Files.size(kept) + " bytes)");
+            }
+            verifyHookedUpdater(tmpJar);
+            byte[] patchedJar = Files.readAllBytes(tmpJar);
+            byte[] out = new byte[start + patchedJar.length];
+            System.arraycopy(all, 0, out, 0, start);
+            System.arraycopy(patchedJar, 0, out, start, patchedJar.length);
+            Path tmp = exe.resolveSibling(exe.getFileName() + ".new");
+            Files.write(tmp, out);
+            replace(tmp, exe);
+            System.out.println("  patched " + exe + " ("
+                    + Files.size(exe) + " bytes, payload at " + start + ")");
+        } finally {
+            Files.deleteIfExists(tmpJar);
+        }
+    }
+
+    /** The embedded jar of an exe, or null when the file has no payload. */
+    private static byte[] payloadOf(Path exe) throws Exception {
+        if (!Files.isRegularFile(exe)) {
+            return null;
+        }
+        byte[] all = Files.readAllBytes(exe);
+        int start = zipStart(all);
+        return start < 0 ? null
+                : Arrays.copyOfRange(all, start, all.length);
+    }
+
+    /** True when the embedded jar already carries our own hook classes. */
+    private static boolean hasHookClass(byte[] jarBytes) throws Exception {
+        Path payload = Files.createTempFile("updater-probe", ".jar");
+        try {
+            Files.write(payload, jarBytes);
+            JarFile jar = new JarFile(payload.toFile());
+            try {
+                return jar.getEntry("rsx/UpdaterHook.class") != null;
+            } finally {
+                jar.close();
+            }
+        } finally {
+            Files.deleteIfExists(payload);
+        }
+    }
+
+    private static int zipStart(byte[] data) {
+        for (int i = 0; i + 4 <= data.length; i++) {
+            if (data[i] == 0x50 && data[i + 1] == 0x4B && data[i + 2] == 0x03
+                    && data[i + 3] == 0x04) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    /** Load the embedded jar, add the hooks, write it back out. */
+    private static byte[] buildHookedUpdater(byte[] originalJar)
+            throws Exception {
+        // JarFile has no stream constructor, so the payload goes to a temp file
+        Path payload = Files.createTempFile("updater-payload", ".jar");
+        Files.write(payload, originalJar);
+        JarFile source = new JarFile(payload.toFile(), true);
+        ClassNode gui = readClass(source, UPDATER_GUI);
+        ClassNode engine = readClass(source, UPDATER_ENGINE);
+        boolean hookedLaunch = false;
+        for (MethodNode m : gui.methods) {
+            if (m.name.equals("runLauncher") && m.desc.startsWith("(Z)")) {
+                InsnList code = new InsnList();
+            code.add(new FieldInsnNode(Opcodes.GETSTATIC, UPDATER_LAUNCHER,
+                    "launcher_folder", "Ljava/lang/String;"));
+                code.add(new MethodInsnNode(Opcodes.INVOKESTATIC, HOOK,
+                        "beforeLauncher", "(Ljava/lang/String;)V", false));
+                m.instructions.insert(code);
+                hookedLaunch = true;
+                System.out.println("  hooked " + UPDATER_GUI + "." + m.name
+                        + m.desc + " -> re-patches app.jar before launch");
+                break;
+            }
+        }
+        if (!hookedLaunch) {
+            throw new IllegalStateException("runLauncher not found in "
+                    + UPDATER_GUI);
+        }
+
+        boolean hookedFilter = false;
+        // findFilesToDownload is where the updater decides what to fetch. We do
+        // NOT touch the call site: for invokespecial the receiver sits *under*
+        // the arguments, so replacing the invoke would need stack surgery.
+        // Instead the original method is renamed and a same-signature wrapper
+        // filters its result - the call site stays byte-identical.
+        final String findDesc =
+                "(Ljava/util/List;Ldownload/manifest/Manifest;)Ljava/util/List;";
+        MethodNode original = null;
+        for (MethodNode m : engine.methods) {
+            if (m.name.equals("findFilesToDownload") && m.desc.equals(findDesc)
+                    && (m.access & Opcodes.ACC_STATIC) == 0) {
+                original = m;
+                break;
+            }
+        }
+        if (original != null) {
+            String renamed = original.name + "$rsxOrig";
+            original.name = renamed;
+
+            MethodNode wrapper = new MethodNode(Opcodes.ASM9,
+                    (original.access & ~Opcodes.ACC_ABSTRACT) | Opcodes.ACC_SYNTHETIC,
+                    "findFilesToDownload", findDesc, null, null);
+            InsnList code = wrapper.instructions;
+            code.add(new VarInsnNode(Opcodes.ALOAD, 0));
+            code.add(new VarInsnNode(Opcodes.ALOAD, 1));
+            code.add(new VarInsnNode(Opcodes.ALOAD, 2));
+            code.add(new MethodInsnNode(Opcodes.INVOKESPECIAL, engine.name,
+                    renamed, findDesc, false));
+            code.add(new VarInsnNode(Opcodes.ASTORE, 3));
+            code.add(new VarInsnNode(Opcodes.ALOAD, 3));
+            code.add(new VarInsnNode(Opcodes.ALOAD, 2));
+            code.add(new MethodInsnNode(Opcodes.INVOKESTATIC, HOOK, "filterUpdates",
+                    "(Ljava/util/List;Ljava/lang/Object;)Ljava/util/List;", false));
+            code.add(new InsnNode(Opcodes.ARETURN));
+            wrapper.maxStack = 3;
+            wrapper.maxLocals = 4;
+            engine.methods.add(wrapper);
+            hookedFilter = true;
+            System.out.println("  hooked " + UPDATER_ENGINE + ".findFilesToDownload"
+                    + " -> keeps our patched app.jar");
+        }
+        if (!hookedFilter) {
+            throw new IllegalStateException("findFilesToDownload not found in "
+                    + UPDATER_ENGINE);
+        }
+
+        ClassWriter guiOut = new ClassWriter(ClassWriter.COMPUTE_MAXS);
+        gui.accept(guiOut);
+        ClassWriter engineOut = new ClassWriter(ClassWriter.COMPUTE_MAXS);
+        engine.accept(engineOut);
+
+        Path tmp = Files.createTempFile("updater-jar", ".jar");
+        try {
+            java.io.ByteArrayOutputStream bos =
+                    new java.io.ByteArrayOutputStream();
+            JarOutputStream outJar = new JarOutputStream(bos);
+            try {
+                Enumeration<JarEntry> entries = source.entries();
+                while (entries.hasMoreElements()) {
+                    JarEntry entry = entries.nextElement();
+                    if (entry.getName().equals(
+                            UPDATER_GUI + ".class")
+                            || entry.getName().equals(
+                                    UPDATER_ENGINE + ".class")
+                            || entry.getName().startsWith("rsx/")) {
+                        continue;
+                    }
+                    JarEntry copy = new JarEntry(entry.getName());
+                    outJar.putNextEntry(copy);
+                    InputStream in = source.getInputStream(entry);
+                    try {
+                        copyStream(in, outJar);
+                    } finally {
+                        in.close();
+                    }
+                    outJar.closeEntry();
+                }
+                outJar.putNextEntry(new JarEntry(UPDATER_GUI + ".class"));
+                outJar.write(guiOut.toByteArray());
+                outJar.closeEntry();
+                outJar.putNextEntry(new JarEntry(UPDATER_ENGINE + ".class"));
+                outJar.write(engineOut.toByteArray());
+                outJar.closeEntry();
+            } finally {
+                source.close();
+                Files.deleteIfExists(payload);
+            }
+            addHookClasses(outJar);
+            outJar.close();
+            return bos.toByteArray();
+        } finally {
+            Files.deleteIfExists(tmp);
+        }
+    }
+
+    /** Load the classes we touched, so the JVM verifier has the last word. */
+    private static void verifyHookedUpdater(Path jar) throws Exception {
+        boolean ok = true;
+        // the loader holds the file open on Windows, so close it before the
+        // temp file is deleted
+        try (java.net.URLClassLoader loader = new java.net.URLClassLoader(
+                new java.net.URL[] {jar.toUri().toURL()},
+                ClassLoader.getSystemClassLoader().getParent())) {
+            for (String name : new String[] {UPDATER_GUI, UPDATER_ENGINE, HOOK}) {
+                try {
+                    // Class.forName wants dots, our targets are written as jar paths
+                    Class.forName(name.replace('/', '.'), true, loader);
+                    System.out.println("  " + name + " verifies");
+                } catch (Throwable t) {
+                    Throwable cause = t;
+                    while (cause.getCause() != null) {
+                        cause = cause.getCause();
+                    }
+                    ok = false;
+                    System.out.println("  " + name + " FAILED: " + cause);
+                }
+            }
+        }
+        if (!ok) {
+            throw new IllegalStateException("hooked updater does not verify");
+        }
+    }
+
+    /** Load a class out of a jar into a mutable tree. */
+    
    /**
- * Put the patched jar in place.
+ * Copy the rsx/ classes this patcher was built with into the jar being written.
+ *
+ * Works both when the patcher runs from its own jar (normal case: friends get
+ * a self-contained jar) and when it runs from a classes directory (dev builds),
+ * so the sources of truth stay the same in both.
+ */
+    private static void addHookClasses(JarOutputStream outJar)
+            throws Exception {
+        Path self = Paths.get(LauncherPatch.class.getProtectionDomain()
+                .getCodeSource().getLocation().toURI());
+        int copied = 0;
+        if (java.nio.file.Files.isDirectory(self)) {
+            Path rsx = self.resolve("rsx");
+            if (java.nio.file.Files.isDirectory(rsync())) {
+                try (java.util.stream.Stream<java.nio.file.Path> files =
+                        java.nio.file.Files.list(rsync())) {
+                    for (java.nio.file.Path p
+                            : (Iterable<java.nio.file.Path>) files::iterator) {
+                        if (!p.getFileName().toString().endsWith(".class")) {
+                            continue;
+                        }
+                        outJar.putNextEntry(new JarEntry(
+                                "rsx/" + p.getFileName()));
+                        outJar.write(java.nio.file.Files.readAllBytes(p));
+                        outJar.closeEntry();
+                        copied++;
+                        System.out.println("  + rsx/" + p.getFileName());
+                    }
+                }
+            }
+        } else {
+            try (JarFile own = new JarFile(self.toFile())) {
+                Enumeration<JarEntry> mine = own.entries();
+                while (mine.hasMoreElements()) {
+                    JarEntry e = mine.nextElement();
+                    if (!e.getName().startsWith("rsx/") || e.isDirectory()) {
+                        continue;
+                    }
+                    outJar.putNextEntry(new JarEntry(e.getName()));
+                    InputStream in = own.getInputStream(e);
+                    try {
+                        copyStream(in, outJar);
+                    } finally {
+                        in.close();
+                    }
+                    outJar.closeEntry();
+                    copied++;
+                    System.out.println("  + " + e.getName());
+                }
+            }
+        }
+        if (copied == 0) {
+            throw new IllegalStateException("no rsx/ classes found next to "
+                    + "the patcher");
+        }
+    }
+
+    private static java.nio.file.Path rsync() throws Exception {
+        return Paths.get(LauncherPatch.class.getProtectionDomain()
+                .getCodeSource().getLocation().toURI()).resolve("rsx");
+    }
+
+    /**
+     * Put the patched jar in place.
 *
 * Antivirus and the shell indexer routinely hold app.jar for a moment, so this
 * retries and falls back through delete+move and plain copy instead of failing
@@ -712,6 +1068,21 @@ private static void replace(Path tmp, Path target) throws Exception {
        return false;
    }

+    /** True once the updater.exe repair has already been replaced by the guard. */
+    private static boolean hasRepairGuard(MethodNode m) {
+        for (AbstractInsnNode insn = m.instructions.getFirst(); insn != null;
+                insn = insn.getNext()) {
+            if (insn instanceof MethodInsnNode) {
+                MethodInsnNode call = (MethodInsnNode) insn;
+                if (GUARD.equals(call.owner)
+                        && "skipUpdaterRepair".equals(call.name)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
    private static boolean hasSelfGuard(MethodNode m) {
        for (AbstractInsnNode insn = m.instructions.getFirst(); insn != null;
                insn = insn.getNext()) {
@@ -822,6 +1193,37 @@ private static void replace(Path tmp, Path target) throws Exception {
        }
    }

+    /**
+     * Records what the untouched jar hashed to. The updater compares this with
+     * the hash in the remote manifest: equal means the only difference is our
+     * own patch and the download can be skipped, different means a real update.
+     */
+    private static void writeMarker(Path jarPath, String baseHash, String patchedHash)
+            throws Exception {
+        Path marker = jarPath.resolveSibling(".rsx-patched");
+        String text = "# app.jar patched in place by the rsx modloader\n"
+                + "baseSha256=" + baseHash + "\n"
+                + "patchedSha256=" + patchedHash + "\n";
+        Files.write(marker, text.getBytes(StandardCharsets.UTF_8));
+        System.out.println("marker: base=" + baseHash + " patched=" + patchedHash);
+    }
+
+    /** Older installs have a marker without hashes; rebuild it from app.jar.orig. */
+    private static void ensureMarker(Path jarPath) throws Exception {
+        Path marker = jarPath.resolveSibling(".rsx-patched");
+        if (Files.isRegularFile(marker)
+                && new String(Files.readAllBytes(marker), StandardCharsets.UTF_8)
+                        .contains("baseSha256=")) {
+            return;
+        }
+        Path backup = jarPath.resolveSibling(jarPath.getFileName() + ".orig");
+        if (!Files.isRegularFile(backup)) {
+            System.out.println("WARNING: no base hash available for " + marker);
+            return;
+        }
+        writeMarker(jarPath, sha256(backup), sha256(jarPath));
+    }
+
    private static String sha256(Path file) throws Exception {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        InputStream in = Files.newInputStream(file);
@@ -67,6 +67,31 @@ public final class Patch {
        }
    }

+    /**
+     * The launcher repairs its own updater.exe on every start: it hashes the
+     * file and, not finding the vendor build, downloads a fresh copy over it.
+     * That silently undoes the hook we installed in updater.exe, so the repair
+     * is skipped while the marker is present.
+     *
+     * Drop .rsx-patched next to app.jar (or pass -Drsx.allowLauncherUpdate=true)
+     * to let the launcher update itself again.
+     */
+    public static void skipUpdaterRepair() {
+        try {
+            if ("true".equalsIgnoreCase(
+                    System.getProperty("rsx.allowLauncherUpdate"))) {
+                log("updater repair allowed by -Drsx.allowLauncherUpdate");
+                return;
+            }
+            File dir = new File(System.getProperty("user.home"),
+                    "AppData/Roaming/kjstudio/launcher");
+            boolean on = new File(dir, ".rsx-patched").isFile();
+            log("skipUpdaterRepair -> " + on);
+        } catch (Throwable t) {
+            log("updater repair guard error: " + t);
+        }
+    }
+
    private static void log(String message) {
        try {
            String appdata = System.getenv("APPDATA");
@@ -0,0 +1,314 @@
+package rsx;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.lang.reflect.Method;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Hook inside the vendor updater.
+ *
+ * The updater compares app.jar against the manifest by hash, so a patched jar
+ * never matches and gets re-downloaded on every start - which silently wipes
+ * the patch. Two hooks handle that:
+ *
+ *  - filterUpdates runs where the updater decides what to fetch. app.jar is
+ *    dropped from the download list only while the manifest still advertises
+ *    the exact hash the patch was applied on top of (recorded in .rsx-patched
+ *    as baseSha256). If the vendor shipped a new launcher the hash differs,
+ *    the file is fetched, and the second hook patches it again.
+ *
+ *  - beforeLauncher runs right before the game is started and re-applies the
+ *    patch when app.jar is not patched - the fresh-install path as well.
+ *
+ * Nothing here may break the updater: every entry point swallows its errors.
+ */
+public final class UpdaterHook {
+
+    private static final String PATCH_MARKER = "rsx/patch.marker";
+    private static final String APP_JAR = "app.jar";
+    private static final String PATCHER = "rsx-launcher-patch.jar";
+
+    private UpdaterHook() {
+    }
+
+    // ------------------------------------------------------------ launch hook
+
+    /** Called at the very start of the updater launching the game. */
+    public static void beforeLauncher(String launcherFolder) {
+        try {
+            if (launcherFolder == null || launcherFolder.isEmpty()) {
+                log("no launcher folder given, skipping");
+                return;
+            }
+            File appJar = new File(launcherFolder, APP_JAR);
+            if (!appJar.isFile()) {
+                log("app.jar not found at " + appJar);
+                return;
+            }
+            if (isPatched(appJar)) {
+                log("app.jar already patched");
+                return;
+            }
+            File patcher = findPatcher();
+            File java = findJava();
+            if (patcher == null || java == null) {
+                log("patcher or java not found (patcher=" + patcher
+                        + ", java=" + java + ")");
+                return;
+            }
+            log("patching app.jar with " + patcher);
+            run(java, patcher, appJar);
+        } catch (Throwable t) {
+            log("beforeLauncher failed: " + t);
+        }
+    }
+
+    // ------------------------------------------------------------ update filter
+
+    /**
+     * Wraps the list the updater is about to download.
+     *
+     * manifest is download.manifest.Manifest, passed as Object so this class
+     * does not have to compile against the updater's own classes.
+     */
+    public static List<?> filterUpdates(List<?> toDownload, Object manifest) {
+        try {
+            log("filterUpdates: " + (toDownload == null ? "null"
+                    : toDownload.size() + " entries"));
+            if (toDownload == null || toDownload.isEmpty()) {
+                return toDownload;
+            }
+            boolean sawAppJar = false;
+            for (Object entry : toDownload) {
+                if (isAppJar(pathOf(entry))) {
+                    sawAppJar = true;
+                    break;
+                }
+            }
+            if (!sawAppJar) {
+                return toDownload;
+            }
+            File appJar = new File(launcherFolder(), APP_JAR);
+            if (!isPatched(appJar)) {
+                return toDownload;
+            }
+            String baseHash = markerValue("baseSha256");
+            String remoteHash = manifestHash(manifest);
+            if (baseHash == null || remoteHash == null) {
+                log("hashes unavailable (base=" + baseHash + ", remote="
+                        + remoteHash + ") - letting the update through");
+                return toDownload;
+            }
+            if (!baseHash.equalsIgnoreCase(remoteHash)) {
+                log("manifest advertises a different app.jar (" + remoteHash
+                        + ") - treating it as a real update");
+                return toDownload;
+            }
+            List<Object> kept = new ArrayList<Object>();
+            for (Object entry : toDownload) {
+                if (isAppJar(pathOf(entry))) {
+                    log("app.jar differs only by our patch - keeping ours");
+                    continue;
+                }
+                kept.add(entry);
+            }
+            return kept;
+        } catch (Throwable t) {
+            log("filterUpdates failed, keeping the list as is: " + t);
+            return toDownload;
+        }
+    }
+
+    // ------------------------------------------------------------ manifest access
+
+    private static String pathOf(Object fileInfo) {
+        try {
+            Method m = fileInfo.getClass().getMethod("getPath");
+            Object v = m.invoke(fileInfo);
+            return v instanceof String ? (String) v : null;
+        } catch (Throwable t) {
+            return null;
+        }
+    }
+
+    private static boolean isAppJar(String path) {
+        return path != null && path.replace('\\', '/').endsWith(APP_JAR);
+    }
+
+    /** The manifest hash for app.jar, read through getFiles(). */
+    private static String manifestHash(Object manifest) {
+        try {
+            Method getFiles = manifest.getClass().getMethod("getFiles");
+            Object files = getFiles.invoke(manifest);
+            if (!(files instanceof Iterable)) {
+                return null;
+            }
+            for (Object fileInfo : (Iterable<?>) files) {
+                if (isAppJar(pathOf(fileInfo))) {
+                    Method getSha = fileInfo.getClass().getMethod("getSha256");
+                    Object sha = getSha.invoke(fileInfo);
+                    return sha instanceof String ? (String) sha : null;
+                }
+            }
+        } catch (Throwable t) {
+            log("cannot read the manifest: " + t);
+        }
+        return null;
+    }
+
+    // ------------------------------------------------------------ marker file
+
+    /** A value from .rsx-patched next to app.jar, written by the patcher. */
+    private static String markerValue(String key) {
+        File marker = new File(launcherFolder(), ".rsx-patched");
+        if (!marker.isFile()) {
+            return null;
+        }
+        try (BufferedReader r = new BufferedReader(new InputStreamReader(
+                new java.io.FileInputStream(marker), StandardCharsets.UTF_8))) {
+            String line;
+            while ((line = r.readLine()) != null) {
+                if (line.startsWith(key + "=")) {
+                    return line.substring(key.length() + 1).trim();
+                }
+            }
+        } catch (Throwable t) {
+            log("cannot read the marker: " + t);
+        }
+        return null;
+    }
+
+    // ------------------------------------------------------------ helpers
+
+    /**
+     * The launcher folder is the "launcher" directory next to the updater. The
+     * updater runs with its own directory as the working directory, so that is
+     * preferred over a hardcoded vendor path - it also keeps the hook correct
+     * when the game is installed somewhere else.
+     */
+    private static String launcherFolder() {
+        File here = workingDir();
+        if (here != null) {
+            File parent = here.getParentFile();
+            File[] candidates = {
+                    parent == null ? null : new File(parent, "launcher"),
+                    here,
+            };
+            for (File candidate : candidates) {
+                if (candidate != null && new File(candidate, APP_JAR).isFile()) {
+                    return candidate.getPath();
+                }
+            }
+        }
+        return new File(System.getProperty("user.home"),
+                "AppData/Roaming/kjstudio/launcher").getPath();
+    }
+
+    private static File updaterDir() {
+        File here = workingDir();
+        if (here != null && new File(here, "updater.exe").isFile()) {
+            return here;
+        }
+        return new File(System.getProperty("user.home"),
+                "AppData/Roaming/kjstudio/updater");
+    }
+
+    private static File workingDir() {
+        String dir = System.getProperty("user.dir");
+        return dir == null || dir.isEmpty() ? null : new File(dir);
+    }
+
+    private static File modHome() {
+        return new File(System.getProperty("user.home"), "AppData/Local/rsx-mod");
+    }
+
+    private static File findPatcher() {
+        File[] candidates = {
+            new File(updaterDir(), PATCHER),
+            new File(modHome(), PATCHER),
+            new File(modHome(), "bridge/" + PATCHER),
+            new File("dist", PATCHER),
+        };
+        for (File c : candidates) {
+            if (c.isFile()) {
+                return c;
+            }
+        }
+        return null;
+    }
+
+    private static File findJava() {
+        String home = System.getProperty("java.home");
+        if (home != null) {
+            File candidate = new File(home, "bin/java.exe");
+            if (candidate.isFile()) {
+                return candidate;
+            }
+        }
+        File jdk = new File(updaterDir(), "bin/java.exe");
+        return jdk.isFile() ? jdk : null;
+    }
+
+    private static void run(File java, File patcher, File appJar) throws Exception {
+        List<String> cmd = new ArrayList<String>();
+        cmd.add(java.getPath());
+        cmd.add("-jar");
+        cmd.add(patcher.getPath());
+        cmd.add("patch");
+        cmd.add(appJar.getPath());
+        cmd.add(modHome().getPath());
+        cmd.add("wa\nALLATORIxDEMO");
+        ProcessBuilder pb = new ProcessBuilder(cmd);
+        pb.directory(updaterDir());
+        pb.redirectErrorStream(true);
+        Process p = pb.start();
+        BufferedReader r = new BufferedReader(new InputStreamReader(
+                p.getInputStream(), StandardCharsets.UTF_8));
+        String line;
+        while ((line = r.readLine()) != null) {
+            log("  " + line);
+        }
+        int code = p.waitFor();
+        log("patcher exited with " + code + ", patched=" + isPatched(appJar));
+    }
+
+    /** True when the jar carries the marker entry written by the patcher. */
+    public static boolean isPatched(File jar) {
+        if (jar == null || !jar.isFile()) {
+            return false;
+        }
+        try {
+            java.util.zip.ZipFile z = new java.util.zip.ZipFile(jar);
+            try {
+                return z.getEntry(PATCH_MARKER) != null;
+            } finally {
+                z.close();
+            }
+        } catch (Throwable t) {
+            return false;
+        }
+    }
+
+    private static void log(String message) {
+        try {
+            File dir = new File(System.getProperty("user.home"),
+                    "AppData/Roaming/kjstudio/rsx-launcher");
+            dir.mkdirs();
+            FileOutputStream os = new FileOutputStream(
+                    new File(dir, "updater-patch.log"), true);
+            PrintWriter w = new PrintWriter(
+                    new OutputStreamWriter(os, StandardCharsets.UTF_8));
+            w.println(message);
+            w.close();
+        } catch (Throwable ignored) {
+            // logging is best effort
+        }
+    }
+}
@@ -0,0 +1,27 @@
+rsxprofile 1
+build 9ad8c4aac5d835fc 9ad8c4aac5d835fc38f68d0648ffd67c809f8342e88b9636ee36205f8f96bf35 3759 7695 59020857 1792011090
+loader ilxq super special.Main
+patch.a2 wsygzaib joml.fastmath
+patch.a6 pvdafug snooper pC
+class net.minecraft.client.Minecraft wwk
+field net.minecraft.client.Minecraft player zb Lwpqgx;
+field net.minecraft.client.Minecraft world ta Lwwhgz;
+field net.minecraft.client.Minecraft currentScreen S Lbsh;
+field net.minecraft.client.Minecraft timer Zb Lmlyn;
+field net.minecraft.client.Minecraft instance WA Lwwk;
+field net.minecraft.client.Minecraft renderGlobal jC Ldqtrv;
+field net.minecraft.client.Minecraft gameSettings y Ldmoadr;
+field net.minecraft.client.Minecraft playerController fa Ltdsh;
+method net.minecraft.client.Minecraft getMinecraft super ()Lwwk;
+method net.minecraft.client.Minecraft displayGuiScreen super (Lbsh;)V
+class net.minecraft.client.entity.EntityPlayerSP wpqgx
+class net.minecraft.entity.player.EntityPlayer obzsyig
+class net.minecraft.world.World oisywi
+class net.minecraft.client.multiplayer.WorldClient wwhgz
+class net.minecraft.entity.Entity ddvqd
+class net.minecraft.entity.EntityLivingBase bgtojhxo
+class net.minecraft.network.PacketBuffer dcuglw
+class net.minecraft.client.multiplayer.PlayerControllerMP tdsh
+class net.minecraft.client.gui.GuiScreen bsh
+class net.minecraft.client.settings.GameSettings qoa
+override.server catch
@@ -101,6 +101,16 @@ if ($Uninstall) {
    Say 'env убран из конфига лаунчера'
    Remove-Item $Marker -Force -ErrorAction SilentlyContinue
    Say 'маркер удалён'
+    # the updater has to go back to stock, otherwise it keeps skipping app.jar
+    # downloads for a launcher that is no longer patched
+    $updaterExe = Join-Path $env:APPDATA 'kjstudio\updater\updater.exe'
+    $updaterBackup = "$updaterExe.orig"
+    if (Test-Path $updaterBackup) {
+        Copy-Item $updaterBackup $updaterExe -Force
+        Remove-Item $updaterBackup -Force
+        Say 'updater.exe восстановлен'
+    }
+    Remove-Item (Join-Path $env:APPDATA 'kjstudio\updater\rsx-launcher-patch.jar') -Force -ErrorAction SilentlyContinue
    Say 'Готово. Лаунчер снова запускается как обычно.' Green
    exit 0
 }
@@ -157,8 +167,14 @@ if ($code -ne 0) {
    Die "Патч не удался (код $code). Если лаунчер запущен с правами администратора - закрой его и повтори."
 }

-Set-Content -LiteralPath $Marker -Value 'patched app.jar: rsx modloader' -Encoding ASCII
-Say 'маркер .rsx-patched создан'
+# the patcher writes .rsx-patched itself: it needs baseSha256 (the hash of the
+# untouched jar) so the updater hook can tell our patch from a real update
+if (-not (Test-Path -LiteralPath $Marker)) {
+    Set-Content -LiteralPath $Marker -Value 'baseSha256=unknown' -Encoding ASCII
+    Say 'маркер .rsx-patched создан'
+} else {
+    Say 'маркер .rsx-patched обновлён патчером'
+}

 # --------------------------------------------------------------- wire the agent
 $agentArg = "-javaagent:`"$ModHome\bridge\rsx-bridge.jar`""
@@ -178,11 +194,35 @@ $check = & $java -jar $patcher showenv $Config 2>&1
 $ErrorActionPreference = $prev
 $check | ForEach-Object { Say $_ }

+# --------------------------------------------------------------- patch the updater
+# The stock updater re-downloads app.jar, which would wipe the patch. We hook its
+# embedded jar so it keeps our app.jar and re-patches after a real update.
+$UpdaterHome = Join-Path $env:APPDATA 'kjstudio\updater'
+$UpdaterExe = Join-Path $UpdaterHome 'updater.exe'
+Say ''
+Say 'Патчу апдейтер...'
+if (-not (Test-Path -LiteralPath $UpdaterExe)) {
+    Say "  не нашёл $UpdaterExe - пропускаю (лаунчер сам предложит обновление)"
+} else {
+    Copy-Item -LiteralPath $patcher -Destination (Join-Path $UpdaterHome 'rsx-launcher-patch.jar') -Force
+    $ErrorActionPreference = 'Continue'
+    $out = & $java -jar $patcher patchupdater $UpdaterExe $ModHome 2>&1
+    $code = $LASTEXITCODE
+    $ErrorActionPreference = $prev
+    $out | ForEach-Object { Say $_ }
+    if ($code -ne 0) {
+        Die "Не удалось пропатчить updater.exe (код $code). Запускай лаунчер через start-launcher.cmd"
+    }
+    if (-not (Test-Path -LiteralPath (Join-Path $UpdaterHome 'updater.exe.orig'))) {
+        Die 'Резервная копия updater.exe не создана - откатываю изменение'
+    }
+}
+
 Say ''
 Say 'Готово.' Green
 Say ''
 Say 'Дальше:'
-Say '  1. запускай лаунчер через start-launcher.cmd, а не ярлыком -'
-Say '     updater.exe перекачает app.jar и сотрёт патч'
+Say '  1. запускай лаунчер обычным ярлыком - обновления больше не сотрут патч'
 Say '  2. жми «Играть» - появится выбор «С модами / Ванилла»'
 Say "  3. моды клади в $ModHome\mods"
+Say '  4. если лаунчер всё же предложит обновление - согласись, патч применится сам'