[racket] Bug in window<%> is-shown?

At Sat, 7 Jan 2012 15:58:31 +0200, Tomi Neste wrote:
> I noticed that sending is-shown? to a GUI object returns #t even when
> the parent top level window is invisible (and correctly returns #f for
> is-shown?). What I understood from the documentation the child objects
> should always return #f when a parent is invisible/closed? This
> happens at least with v5.2 running in Ubuntu 10.04.

I'll revise the documentation to be more clear. The intent is that
`is-shown?' reflects only whether the window is shown relative to its
parent (i.e., in the case that the parent is shown, whether the window
would be shown).