bug#49138: 25.3; window title for multiple frames

[Ulrich Windl]

This is a "old bug": When you start Emacs with a single frame, the
"window" title is "Emacs@host.domain.org", independent on the buffer you
are visiting in single-window mode.
However when you open another frame (C-x 5 b), the tiles of the
"windows" change to the buffer name (precisely: to the name of the
active window when there are multiple windows in the frame).
I think it would be both, consistent and helpful if Emacs would use
"window" title "Emacs@host.domain.org X" in all cases, where X could be
either the name of the active window in the frame, or a (possibly
abbreviated) list of windows being displayed in that frame.
Note: I'm using "window" in double-quotes when I talk about the window
manager's windows (like X11 windows), not about Emacs windows (that are
parts of a frame).

In GNU Emacs 25.3.1 (x86_64-suse-linux-gnu, GTK+ Version 3.22.30)
 of 2021-01-12 built on sheep16
Windowing system distributor 'The X.Org Foundation', version 11.0.12003000
System Description:    openSUSE Leap 15.3
Configured using:
 'configure --with-pop --without-hesiod --with-kerberos --with-kerberos5
 --with-xim --with-wide-int --with-file-notification=inotify
 --with-modules --enable-autodepend --prefix=/usr
 --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share
 --localstatedir=/var --sharedstatedir=/var/lib --libexecdir=/usr/lib
 
--enable-locallisppath=/usr/share/emacs/25.3/site-lisp:/usr/share/emacs/site-lisp
 --with-x --with-sound --with-xpm --with-jpeg --with-tiff --with-gif
 --with-png --with-rsvg --with-dbus --with-xft --without-gpm
 --with-x-toolkit=gtk3 --with-xwidgets --with-toolkit-scroll-bars
 --x-includes=/usr/include --x-libraries=/usr/lib64 --with-libotf
 --with-m17n-flt --build=x86_64-suse-linux 'CFLAGS=-fmessage-length=0
 -grecord-gcc-switches -O2 -Wall -D_FORTIFY_SOURCE=2
 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables
 -fstack-clash-protection -g -D_GNU_SOURCE
 -DGDK_DISABLE_DEPRECATION_WARNINGS -DGLIB_DISABLE_DEPRECATION_WARNINGS
 -pipe -Wno-pointer-sign -Wno-unused-variable -Wno-unused-label
 -Wno-unprototyped-calls -fno-optimize-sibling-calls -fno-PIE
 -DSYSTEM_PURESIZE_EXTRA=55000 -DSITELOAD_PURESIZE_EXTRA=10000 '
 LDFLAGS=-Wl,-O2'
Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS GCONF GSETTINGS NOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 MODULES XWIDGETS
Important settings:
  value of $LC_NUMERIC: POSIX
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=local
  locale-coding-system: utf-8-unix
Major mode: C/l
Minor modes in effect:
  shell-dirtrack-mode: t
  diff-auto-refine-mode: t
  show-paren-mode: t
  tooltip-mode: t
  global-eldoc-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
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t
Recent messages:
Wrote /home/wiu09524/Projekte/bitmap/bitmap.h
Compilation exited abnormally with code 2
Saving file /home/wiu09524/Projekte/bitmap/bitmap.h...
Wrote /home/wiu09524/Projekte/bitmap/bitmap.h
Compilation finished
<mouse-6> is undefined
<double-mouse-6> is undefined
Mark saved where search started
Mark set
Mark saved where search started [8 times]
Load-path shadows:
None found.
Features:
(shadow sort mail-extr warnings emacsbug message dired format-spec
rfc822 mml mml-sec password-cache epg epg-config gnus-util mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mm-util help-fns mail-prsvr
mail-utils shell pcomplete compile comint ansi-color ring misearch
multi-isearch vc-git diff-mode easy-mmode cl-extra help-mode cc-mode
cc-fonts easymenu cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine
cc-vars cc-defs cl-loaddefs pcase cl-lib xfonts rmailgen paren time-date
mule-util delsel lpr tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel x-win term/common-win x-dnd tool-bar dnd fontset
image regexp-opt fringe tabulated-list newcomment elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cl-generic 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 charscript case-table epa-hook
jka-cmpr-hook help simple abbrev minibuffer cl-preloaded nadvice
loaddefs button faces cus-face macroexp files text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote dbusbind inotify dynamic-setting
system-font-setting font-render-setting xwidget-internal move-toolbar
gtk x-toolkit x multi-tty make-network-process emacs)
Memory information:
((conses 16 149820 7471)
 (symbols 48 23297 0)
 (miscs 40 171 551)
 (strings 32 24361 5399)
 (string-bytes 1 821050)
 (vectors 16 17752)
 (vector-slots 8 527633 5978)
 (floats 8 185 275)
 (intervals 56 8122 18)
 (buffers 976 22))