tty-child-frames does not seem to play well with multiple clients. When we
run server-start and allow emacs to have multiple clients (e.g. an initial
"emacs -nw" and an
"emacsclient -nw"), using a function that utilizes tty-child-frame (such as
M-x when vertico-posframe is loaded) in one frame leads the other client to
be locked up.

Steps to reproduce:

mkdir ~/emacs-test
Copy the attached init.el into ~/emacs-test/
emacs -nw --init-directory=~/emacs-test  (the first time will result in
packages being installed by elpaca)
(in another terminal) emacsclient -nw
Do something to invoke the child frame pop up (e.g. C-x b and select a
buffer)
Switch back to the original emacs
Do something to invoke the child frame pop up (e.g. C-x b and select a
buffer)
Swap to the other terminal, and note that at some point one client will
stop responding
to user input. (It may take a couple of tries, perhaps with other regular
commands interspersed).
When one client is locked, swap back to the other terminal and exit the
client - the original
client will now accept user input.

When a client is locked it *does* accept some input (e.g. C-x C-c will exit
the client)

It's possible this is vertico-posframe related, as I can't trigger similar
behaviour using transient-posframe.


In GNU Emacs 31.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
 3.24.41, cairo version 1.18.0) of 2024-12-24 built on kaka
Repository revision: 6ac38396898e6324d4c6dddb2ad05d1ad0dc5e7c
Repository branch: master
System Description: Ubuntu 24.04.1 LTS

Configured using:
 'configure --prefix=/home/len/.local --with-rsvg --with-cairo
 --with-native-compilation --with-tree-sitter --with-modules'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 M17N_FLT MODULES NATIVE_COMP
NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER WEBP X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB

Important settings:
  value of $LC_MONETARY: en_AU.UTF-8
  value of $LC_NUMERIC: en_AU.UTF-8
  value of $LC_TIME: en_AU.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
  xterm-mouse-mode: t
  server-mode: t
  vertico-posframe-mode: t
  vertico-mode: t
  elpaca-use-package-mode: t
  override-global-mode: t
  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
  minibuffer-regexp-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 compile comint ansi-osc ansi-color ring comp-run
comp-common rx emacsbug message yank-media puny dired dired-loaddefs
rfc822 mml mml-sec epa derived epg rfc6068 epg-config gnus-util
text-property-search time-date mm-decode mm-bodies mm-encode mail-parse
rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mail-utils xt-mouse term/xterm xterm
server vertico-posframe vertico-multiform vertico compat posframe
vertico-posframe-autoloads vertico-autoloads posframe-autoloads cl-extra
help-mode elpaca-use-package use-package use-package-ensure
use-package-delight use-package-diminish use-package-bind-key bind-key
easy-mmode use-package-core elpaca-use-package-autoloads elpaca-log
elpaca-ui elpaca-menu-elpa elpaca-menu-melpa url url-proxy url-privacy
url-expand url-methods url-history url-cookie generate-lisp-file
url-domsuf url-util url-parse auth-source cl-seq eieio eieio-core
cl-macs password-cache json subr-x map byte-opt gv bytecomp byte-compile
url-vars mailcap elpaca-menu-org elpaca warnings icons elpaca-process
cl-loaddefs cl-lib elpaca-autoloads rmc iso-transl tooltip cconv eldoc
paren electric uniquify ediff-hook vc-hooks lisp-float-type elisp-mode
mwheel term/x-win x-win term/common-win x-dnd touch-screen 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 dbusbind inotify lcms2
dynamic-setting system-font-setting font-render-setting cairo gtk
x-toolkit xinput2 x multi-tty move-toolbar make-network-process
tty-child-frames native-compile emacs)

Memory information:
((conses 16 396223 19518) (symbols 48 15669 0)
 (strings 32 187599 3392) (string-bytes 1 2901786) (vectors 16 17588)
 (vector-slots 8 194405 8250) (floats 8 78 41) (intervals 56 346 0)
 (buffers 992 19))