CLOSES #575, CLOSES #578, CLOSES #584, CLOSES #589

mobile/android/love/src/jni/love/src/common/android.cpp

@@ -231,6 +231,28 @@ bool syncHealthSteps()
 	return result;
 }
 
+bool restartApp()
+{
+	JNIEnv *env = (JNIEnv*) SDL_AndroidGetJNIEnv();
+	jclass activity = env->FindClass("org/love2d/android/GameActivity");
+
+	// Old APK / new liblove skew: fail soft so HostShell.restart can fall
+	// back to a clean quit instead of aborting on a missing method (#575).
+	jmethodID method = env->GetStaticMethodID(activity, "restartApp", "()Z");
+	if (method == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return false;
+	}
+
+	// Does not return on success: the Java side exits the process.
+	jboolean result = env->CallStaticBooleanMethod(activity, method);
+
+	env->DeleteLocalRef(activity);
+	return result;
+}
+
 /*
  * Helper functions for the filesystem module
  */

mobile/android/love/src/jni/love/src/common/android.h

@@ -81,6 +81,15 @@ bool showCreateDocument(const char *suggestedName = nullptr);
  */
 bool syncHealthSteps();
 
+/**
+ * Full process relaunch (GameActivity.restartApp): schedules the app's
+ * launch intent and kills the process, because the in-process
+ * quit("restart") loop double-inits physfs and crashes (#575). On success
+ * the process dies inside the Java call and this never returns; false
+ * means the relaunch could not be scheduled.
+ **/
+bool restartApp();
+
 /*
  * Helper functions for the filesystem module
  */

mobile/android/love/src/jni/love/src/modules/system/System.cpp

@@ -221,6 +221,15 @@ bool System::syncHealthSteps() const
 #endif
 }
 
+bool System::restartApp() const
+{
+#ifdef LOVE_ANDROID
+	return love::android::restartApp();
+#else
+	return false;
+#endif
+}
+
 bool System::hasBackgroundMusic() const
 {
 #if defined(LOVE_ANDROID)

mobile/android/love/src/jni/love/src/modules/system/System.h

@@ -133,6 +133,14 @@ public:
 	 */
 	virtual bool syncHealthSteps() const;
 
+	/**
+	 * Relaunches the whole app with a fresh process (Android only; false
+	 * elsewhere). The in-process love.event.quit("restart") double-inits
+	 * physfs on Android and crashes, so src/core/HostShell.lua calls this
+	 * instead (#575). Does not return on success -- the process exits.
+	 **/
+	virtual bool restartApp() const;
+
 	/**
 	 * Gets if the user is playing music on background.
 	 * Throws an exception on unsupported platforms.

mobile/android/love/src/jni/love/src/modules/system/wrap_System.cpp

@@ -115,6 +115,14 @@ int w_syncHealthSteps(lua_State *L)
 	return 1;
 }
 
+int w_restartApp(lua_State *L)
+{
+	// Does not return on success: GameActivity.restartApp exits the process
+	// after scheduling the relaunch (#575).
+	luax_pushboolean(L, instance()->restartApp());
+	return 1;
+}
+
 int w_hasBackgroundMusic(lua_State *L)
 {
 	lua_pushboolean(L, instance()->hasBackgroundMusic());
@@ -133,6 +141,7 @@ static const luaL_Reg functions[] =
 	{ "pickFile", w_pickFile },
 	{ "createFile", w_createFile },
 	{ "syncHealthSteps", w_syncHealthSteps },
+	{ "restartApp", w_restartApp },
 	{ "hasBackgroundMusic", w_hasBackgroundMusic },
 	{ 0, 0 }
 };