### Godot version

v4.0.beta9.official [e780dc332]

### System information

macOS Ventura 13.0.1 (Intel), Radeon Pro 580 8 GB

### Issue description

When setting the size of a SubViewport (that is inside the corresponding SubViewportContainer) to zero, the editor crashes instantly.

**But it only happens when I set the size of the SubViewport by sliding the values.**

You can see what happens in this video:


https://user-images.githubusercontent.com/91340577/209363880-503d3dff-80e1-4e9e-bb57-d059fdbfeed0.mp4

At the end of the video you can see the crash message of macOS reading: _Godot quit unexpectedly._

If I write the number zero (or any negative) to the values of the SubViewport size, the crash doesn't happens.

### Steps to reproduce

1. Add a SubViewportContainer
2. Add a SubViewport as a child of the SubViewportContainer
3. Set the size of the SubViewport to zero **by sliding** the X or the Y value.

### Minimal reproduction project

1. Open the project
2. Go to the Control.tscn scene
3. Select the SubViewport node
4. Slide the X or Y values of the size to zero

[SubViewportCrash.zip](https://github.com/godotengine/godot/files/10296101/SubViewportCrash.zip)
ERR_FAIL_COND(p_event.is_null());
	Ref<InputEventMouseButton> mb = p_event;
	if (mb.is_valid()) {
		gui.key_event_accepted = false;
		Point2 mpos = mb->get_position();
		if (mb->is_pressed()) {
			if (!gui.mouse_focus_mask.is_empty()) {
				
				gui.mouse_focus_mask.set_flag(mouse_button_to_mask(mb->get_button_index()));
			} else {
				gui.mouse_focus = gui_find_control(mpos);
				gui.last_mouse_focus = gui.mouse_focus;
				if (!gui.mouse_focus) {
					gui.mouse_focus_mask.clear();
					return;
				}
				gui.mouse_focus_mask.clear();
				gui.mouse_focus_mask.set_flag(mouse_button_to_mask(mb->get_button_index()));
				if (mb->get_button_index() == MouseButton::LEFT) {
					gui.drag_accum = Vector2();
					gui.drag_attempted = false;
				}
			}
			mb = mb->xformed_by(Transform2D()); 
			Point2 pos = gui.mouse_focus->get_global_transform_with_canvas().affine_inverse().xform(mpos);