Huge gap between fringe and scroll-bar

[Leo]

Emacs's native scroll-bar (--without-toolkit-scroll-bars) can have a
huge gap between fringe and scroll-bar. To see this:

  emacs -Q -l sb.el

Where sb.el has:
,----[ sb.el ]
| (setq initial-frame-alist
|       '((scroll-bar-width . 10)))
`----

As you can see the gap between the fringe and scroll-bar is close to
8 pixels. I see no gap for gtk scroll-bar though.

Screenshot:

To compare:

  emacs -Q

Screenshot:

BTW, can I set scroll-bar width in X resource file?

-- 
Leo <sdl.web AT gmail.com>                         (GPG Key: 9283AA3F)