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

[Eli Zaretskii <eliz@gnu.org>]

> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Sun, 14 Jul 2013 19:02:27 +0200
> Cc: 14841@debbugs.gnu.org
> 
> On Sun, Jul 14, 2013 at 6:52 PM, Eli Zaretskii <eliz@gnu.org> wrote:
> 
> > I'm confused: what did you expect to happen instead?
> 
> After this, (nil t) instead of (t  t)
> 
> >>   emacs -Q
> >>   M-: (make-frame '((visibility))) <RET>
> >>   M-: (mapcar #'frame-visible-p (frame-list)) <RET>
> >>   => (t t)
> 
> because:
> 
>  1) (make-frame '((visibility))) == (make-frame '((visibility . nil)))
>  2) The frame *is* invisible
>  3) If you do this instead:  M-: (progn (make-frame '((visibility)))
> (mapcar #'frame-visible-p (frame-list))) <RET>, you get (nil t)

This happens because we get a WM_SIZE message, in response to which we
unconditionally set the frame as visible:

	case WM_SIZE:
	  f = x_window_to_frame (dpyinfo, msg.msg.hwnd);

	  /* Inform lisp of whether frame has been iconified etc. */
	  if (f)
	    {
	      switch (msg.msg.wParam)
		{
                ....
		case SIZE_MAXIMIZED:
		case SIZE_RESTORED:
		  {
		    bool iconified = FRAME_ICONIFIED_P (f);

		    SET_FRAME_VISIBLE (f, 1);   <<<<<<<<<<<<<<<<<<<<<
		    SET_FRAME_ICONIFIED (f, 0);

I'm out of my depth here, as I know close to nothing about the details
of these messages, and why are they sent to us, even though the frame
is created invisible.  But try the changes below for a few days, and
if they don't have any adverse effects, I will install them.

=== modified file 'src/w32term.c'
--- src/w32term.c	2013-07-18 16:50:05 +0000
+++ src/w32term.c	2013-07-20 12:41:06 +0000
@@ -4360,8 +4360,9 @@ w32_read_socket (struct terminal *termin
 		  SET_FRAME_VISIBLE (f, 1);
 		  SET_FRAME_ICONIFIED (f, 0);
 		  SET_FRAME_GARBAGED (f);
-		  DebPrint (("frame %p (%s) reexposed by WM_PAINT\n", f,
-			     SDATA (f->name)));
+		  if (!f->output_data.w32->asked_for_visible)
+		    DebPrint (("frame %p (%s) reexposed by WM_PAINT\n", f,
+			       SDATA (f->name)));
 
 		  /* WM_PAINT serves as MapNotify as well, so report
 		     visibility changes properly.  */
@@ -4819,7 +4820,8 @@ w32_read_socket (struct terminal *termin
 		  {
 		    bool iconified = FRAME_ICONIFIED_P (f);
 
-		    SET_FRAME_VISIBLE (f, 1);
+		    if (iconified)
+		      SET_FRAME_VISIBLE (f, 1);
 		    SET_FRAME_ICONIFIED (f, 0);
 
 		    /* wait_reading_process_output will notice this