EditorUndoRedoManager prints wrong errors if calling method fails

[KoBeWi]

Tested versions

4.3 dev5 and earlier

System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 31.0.15.4633) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

Issue description

Consider this code:

@tool
extends EditorScript

func _run() -> void:
	var eur := EditorPlugin.new().get_undo_redo()
	eur.create_action("a")
	eur.add_do_method(get_scene(), "set_modulat", 1)
	eur.add_do_method(get_scene(), "draw_texture", 1)
	eur.add_undo_method(get_scene(), "set_modulat")
	eur.commit_action()

Assuming get_scene() returns Node2D, the first "do" method does not exist, while the second has wrong number of arguments. The errors printed are:

  C:\godot_source\core/object/undo_redo.cpp:367 - Error calling UndoRedo method operation 'set_modulat': 'Node2D::set_modulat': Instance is null
  C:\godot_source\core/object/undo_redo.cpp:367 - Error calling UndoRedo method operation 'draw_texture': 'Node2D::draw_texture': Method expected 3 arguments, but called with 0

The first error says "instance is null" (it's not)
The second error says the method is called with 0 arguments (while it uses 1)

Doesn't seem like a bug strictly in EditorUndoRedoManager (or UndoRedo), I don't know what's causing it.

Steps to reproduce

Run the code above.

Minimal reproduction project (MRP)

N/A

[jsjtxietian]

is_valid doesn't distinguish whether the instance is null or it doesn't have the method

bool Callable::is_valid() const {
	if (is_custom()) {
		return get_custom()->is_valid();
	} else {
		return get_object() && get_object()->has_method(get_method());
	}
}