### 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)
bool stopped = false;
			if (gui.mouse_focus && gui.mouse_focus->can_process()) {
				stopped = _gui_call_input(gui.mouse_focus, mb);
			}
			if (stopped) {
				set_input_as_handled();
			}
			if (gui.dragging && mb->get_button_index() == MouseButton::LEFT) {
				
				_perform_drop(gui.mouse_focus, pos);
			}
			_gui_cancel_tooltip();
		} else {
			if (gui.dragging && mb->get_button_index() == MouseButton::LEFT) {
				_perform_drop(gui.drag_mouse_over, gui.drag_mouse_over_pos);
			}
			gui.mouse_focus_mask.clear_flag(mouse_button_to_mask(mb->get_button_index())); 
			if (!gui.mouse_focus) {
				
				return;
			}
			mb = mb->xformed_by(Transform2D()); 
			Point2 pos = gui.mouse_focus->get_global_transform_with_canvas().affine_inverse().xform(mpos);
			mb->set_position(pos);
			Control *mouse_focus = gui.mouse_focus;
			
			
			
			if (gui.mouse_focus_mask.is_empty()) {
				gui.mouse_focus = nullptr;