bug#55727: 29.0.50; Incorrect zero symbol transcoding between applications

["Петров Андрей" <an.petrov@pay-lab.ru>]

Hello, team!

Please check the following behavior:

1. Start two instances of emacs -Q.
2. Switch to the "*scratch*" buffer of the first one and type the following:
   M-: (insert (format "%S"  "000\000000")) [RET]
   You should see "000^@000" string.
3. Copy the string into clipboard and paste into the other instance of
   Emacs (which you have started before).
   I get "000\0000" instead of "000\000000"
4. Try evaluating inserted text ("000\0000")
   C-c C-e
   I get "000^@0" instead of "000^@000".

It seems that "^@" is transcoded between applications into "\0"
 instead of "\000". If I do the same test inside single instance
 of Emacs I get the correct result.


In GNU Emacs 29.0.50 (build 3, x86_64-pc-linux-gnu, GTK+ Version 3.24.34, cairo version 1.17.6)
 of 2022-05-30 built on pva-msi
Repository revision: 004e6ae3f42bdc8cd632060f56dbf8c1ea850c4a
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101003
System Description: Arch Linux

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

Important settings:
  value of $LANG: ru_RU.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
  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
  font-lock-mode: t
  blink-cursor-mode: 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 rmc puny
dired dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg
rfc6068 epg-config gnus-util text-property-search seq gv byte-opt
bytecomp byte-compile cconv 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 subr-x cl-loaddefs
cl-lib cyril-util iso-transl tooltip eldoc paren electric uniquify
ediff-hook vc-hooks lisp-float-type elisp-mode 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 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 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 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 move-toolbar gtk x-toolkit xinput2 x multi-tty
make-network-process emacs)

Memory information:
((conses 16 43966 8699)
 (symbols 48 5718 1)
 (strings 32 15667 1941)
 (string-bytes 1 509558)
 (vectors 16 11167)
 (vector-slots 8 162892 11831)
 (floats 8 23 52)
 (intervals 56 457 0)
 (buffers 992 11))


Best regards,
Andrey Petrov.