bug#14841: Frames created invisible have their visibility parameter set to t

[Eli Zaretskii <eliz@gnu.org>]

> Cc: eliz@gnu.org
> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Thu, 11 Jul 2013 17:14:19 +0200
> 
> Anyway, the bug: frames made invisible with set-frame-parameter,
> modify-frame-parameters or make-frame-invisible have their visibility
> parameter really set to nil. However, frames created already invisible
> with (make-frame '((visibility . nil)), which *are* invisible, have
> their visibility parameter set to t as soon as there's some redisplay.
> [...]
> This could be related to this comment in frame.h
> 
>      On ttys and on Windows NT/9X, to avoid wasting effort updating
>      visible frames that are actually completely obscured by other
>      windows on the display, we bend the meaning of visible slightly:
>      if equal to 2, then the frame is obscured - we still consider
>      it to be "visible" as seen from lisp, but we don't bother
>      updating it.  We must take care to garbage the frame when it
>      ceases to be obscured though.  See SET_FRAME_VISIBLE below.  */
>   unsigned visible : 2;

I don't see how this is related to the bug you describe.  Can you
elaborate why you think it is?