bug#30382: 27.0.50; emacsclient -c creates frame in wrong Emacs when started from inside Emacs

[p . stephani2]

1. On machine A, in a graphical environment, start Emacs as usual.
2. Start the server (M-x server-start).
3. From another machine B, ssh into A.
4. Open a terminal frame with emacsclient -t.
5. Start a shell with M-x shell.
6. From within the shell, run emacsclient -c.
7. Emacs will open a new graphical frame on A.  There's no way to
   interact with that frame from B.

In step 6, the Emacs client should detect that it's being run from
inside Emacs, and should replace the current frame on B with a temporary
client frame instead of opening a new frame on A.


In GNU Emacs 27.0.50 (build 11, x86_64-pc-linux-gnu, GTK+ Version 3.22.24)
 of 2018-02-07 built on localhost
Repository revision: a710f8aa61ca73054109dc4f926d1ac6aabdd849
Windowing system distributor 'The X.Org Foundation', version 11.0.11903000
System Description: Debian GNU/Linux buster/sid

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Configured using:
 'configure --without-threads --enable-gcc-warnings=3Dwarn-only
 --enable-gtk-deprecation-warnings --without-pop --with-mailutils
 --enable-checking --enable-check-lisp-object-type --with-modules
 'CFLAGS=3D-O0 -ggdb3''

Configured features:
XPM JPEG TIFF GIF PNG SOUND DBUS GSETTINGS NOTIFY GNUTLS FREETYPE XFT
ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 MODULES JSON

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

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  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
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny seq byte-opt gv
bytecomp byte-compile cconv cl-loaddefs cl-lib dired dired-loaddefs
format-spec rfc822 mml easymenu mml-sec password-cache epa derived epg
epg-config gnus-util rmail rmail-loaddefs mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047
rfc2045 ietf-drums mm-util mail-prsvr mail-utils elec-pair time-date
mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar
dnd fontset image regexp-opt fringe tabulated-list replace newcomment
text-mode elisp-mode lisp-mode prog-mode register page menu-bar
rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core term/tty-colors 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 composite charscript charprop
case-table epa-hook jka-cmpr-hook help simple abbrev obarray 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 move-toolbar gtk
x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 95306 11515)
 (symbols 48 20241 1)
 (miscs 40 40 121)
 (strings 32 28312 2006)
 (string-bytes 1 757347)
 (vectors 16 14137)
 (vector-slots 8 499140 13640)
 (floats 8 49 100)
 (intervals 56 225 0)
 (buffers 992 12))

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