### 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)
next = from->_get_focus_neighbor(SIDE_BOTTOM);
				}
			} else {
				if (p_event->is_action_pressed("ui_focus_next", true, true)) {
					next = from->find_next_valid_focus();
				}
				if (p_event->is_action_pressed("ui_focus_prev", true, true)) {
					next = from->find_prev_valid_focus();
				}
				if (p_event->is_action_pressed("ui_up", true, true)) {
					next = from->_get_focus_neighbor(SIDE_TOP);
				}
				if (p_event->is_action_pressed("ui_left", true, true)) {
					next = from->_get_focus_neighbor(SIDE_LEFT);
				}
				if (p_event->is_action_pressed("ui_right", true, true)) {
					next = from->_get_focus_neighbor(SIDE_RIGHT);
				}
				if (p_event->is_action_pressed("ui_down", true, true)) {
					next = from->_get_focus_neighbor(SIDE_BOTTOM);
				}
			}
			if (next) {
				next->grab_focus();
				set_input_as_handled();
			}
		}
	}
}
void Viewport::_perform_drop(Control *p_control, Point2 p_pos) {