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

[Juanma Barranquero <lekktu@gmail.com>]

On Thu, Jul 11, 2013 at 5:33 PM, Eli Zaretskii <eliz@gnu.org> wrote:

>> 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?

That's a trick question. I don't know, that's why I said "could be
related". Why did I think so? Because the comment clearly describes a
case where a frame is not "visible" (on the screen) and yet "visible"
(to lisp).

Also, because it does not seem a bug in make-frame (after make-frame,
the frame has visibility = nil as expected); it is only noticeable
after redisplay; or at least, after the command is finished, which
suggests that redisplay was likely triggered.

But I could be wrong, of course. It's known to happen every now and then ;-)