bug#64630: 30.0.50; unable to change to raise or lower a child-frame

[Andrey Listopadov <andreyorst@gmail.com>]

Hello.

I'm working on an alternative windowing system for Emacs that explores
child frames as a base for windowing, instead of using splits.  I've
noticed that no matter what I do, I can't restack child-frames.  Calling
`frame-raise' or changing the `z-group' has no effect on the frames
spawned by my window manager.

The simplest possible way to test this in Emacs -Q is to eval this code
twice:

(let ((frame
       (make-frame
	`((width . 20) (height . 8)
	  (parent-frame . ,(selected-frame))
	  (drag-with-header-line . t)
	  (undecorated . t)
	  (minibuffer . nil)))))
  (set-window-parameter
   (frame-root-window frame)
   'header-line-format
   " %b"))

It will create two small child frames, and no matter what I do the order
of frames is not changes.  A friend of mine reported that it works under
X on Emacs 28 as expected.  I suspect that it may be related to the fact
that I'm using Wayland version of GNOME Shell and a PGTK build. I will
try to recompile Emacs later and post the results here.

The window manager can be obtained here[1] if you want to experiment with
it but the snipped above should be sufficient.


In GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.38, cairo version 1.17.8) of 2023-07-07 built on toolbox
Repository revision: 37101780243d083e8773c255242aa26614f22a14
Repository branch: master
System Description: Fedora Linux 38 (Container Image)

Configured using:
 'configure --without-compress-install --with-native-compilation=aot
 --with-pgtk --with-mailutils --with-xwidgets
 --prefix=/var/home/alist/.local'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSELINUX LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY
PDUMPER PGTK PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER XIM XWIDGETS GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Infinite

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  blink-cursor-mode: t
  buffer-read-only: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa epg rfc6068
epg-config gnus-util text-property-search mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils time-date infinite
derived pcase vc-git diff-mode easy-mmode vc-dispatcher cl-loaddefs comp
comp-cstr warnings icons subr-x rx cl-seq cl-macs gv cl-extra help-mode
bytecomp byte-compile cl-lib rmc iso-transl tooltip cconv eldoc paren
electric uniquify ediff-hook vc-hooks lisp-float-type elisp-mode mwheel
term/pgtk-win pgtk-win term/common-win pgtk-dnd tool-bar dnd fontset
image regexp-opt fringe tabulated-list replace newcomment text-mode
lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch
easymenu timer select scroll-bar mouse jit-lock font-lock syntax
font-core term/tty-colors frame minibuffer nadvice seq simple cl-generic
indonesian philippine cham georgian utf-8-lang misc-lang vietnamese
tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
composite emoji-zwj charscript charprop case-table epa-hook
jka-cmpr-hook help abbrev obarray oclosure cl-preloaded button loaddefs
theme-loaddefs faces cus-face macroexp files window text-properties
overlay sha1 md5 base64 format env code-pages mule custom widget keymap
hashtable-print-readable backquote threads xwidget-internal dbusbind
inotify dynamic-setting system-font-setting font-render-setting cairo
gtk pgtk lcms2 multi-tty move-toolbar make-network-process
native-compile emacs)

Memory information:
((conses 16 89926 11925) (symbols 48 7843 0) (strings 32 21861 1792)
 (string-bytes 1 674782) (vectors 16 17291)
 (vector-slots 8 356861 18308) (floats 8 33 44) (intervals 56 347 0)
 (buffers 984 13))

[1] https://gitlab.com/andreyorst/infinite.el/-/blob/d8740f5657a880620456f8fabd16fe3d8a5918b8/infinite.el