Ensure MainLoop and its custom script is set right after it's resolved

core/os/main_loop.cpp

@@ -52,15 +52,7 @@ void MainLoop::_bind_methods() {
 	GDVIRTUAL_BIND(_finalize);
 }
 
-void MainLoop::set_initialize_script(const Ref<Script> &p_initialize_script) {
-	initialize_script = p_initialize_script;
-}
-
 void MainLoop::initialize() {
-	if (initialize_script.is_valid()) {
-		set_script(initialize_script);
-	}
-
 	GDVIRTUAL_CALL(_initialize);
 }
 

core/os/main_loop.h

@@ -39,8 +39,6 @@
 class MainLoop : public Object {
 	GDCLASS(MainLoop, Object);
 
-	Ref<Script> initialize_script;
-
 protected:
 	static void _bind_methods();
 
@@ -69,8 +67,6 @@ public:
 	virtual bool process(double p_time);
 	virtual void finalize();
 
-	void set_initialize_script(const Ref<Script> &p_initialize_script);
-
 	MainLoop() {}
 	virtual ~MainLoop() {}
 };

main/main.cpp

@@ -2657,7 +2657,7 @@ bool Main::start() {
 				ERR_FAIL_V_MSG(false, vformat("Can't load the script \"%s\" as it doesn't inherit from SceneTree or MainLoop.", script));
 			}
 
-			script_loop->set_initialize_script(script_res);
+			script_loop->set_script(script_res);
 			main_loop = script_loop;
 		} else {
 			return false;
@@ -2680,7 +2680,7 @@ bool Main::start() {
 				OS::get_singleton()->alert("Error: Invalid MainLoop script base type: " + script_base);
 				ERR_FAIL_V_MSG(false, vformat("The global class %s does not inherit from SceneTree or MainLoop.", main_loop_type));
 			}
-			script_loop->set_initialize_script(script_res);
+			script_loop->set_script(script_res);
 			main_loop = script_loop;
 		}
 	}
@@ -2705,6 +2705,8 @@ bool Main::start() {
 		}
 	}
 
+	OS::get_singleton()->set_main_loop(main_loop);
+
 	SceneTree *sml = Object::cast_to<SceneTree>(main_loop);
 	if (sml) {
 #ifdef DEBUG_ENABLED
@@ -3054,8 +3056,6 @@ bool Main::start() {
 		DisplayServer::get_singleton()->set_icon(icon);
 	}
 
-	OS::get_singleton()->set_main_loop(main_loop);
-
 	if (movie_writer) {
 		movie_writer->begin(DisplayServer::get_singleton()->window_get_size(), fixed_fps, Engine::get_singleton()->get_write_movie_path());
 	}