bug#56879: 29.0.50; scp method for files without access, should give better error

[Jean Louis <bugs@gnu.support>]

When I use scp Tramp method and try to access as user a file that may be
opened only as root, I get scree unexpected error, gzip something.

That is weird message. Tramp shall recognize if file can be opened by
user or not and then give proper message, and not attempt to open file
and give misleading messages.


In GNU Emacs 29.0.50 (build 14, x86_64-pc-linux-gnu, X toolkit, cairo version 1.17.6, Xaw3d scroll bars)
 of 2022-07-23 built on protected.rcdrun.com
Repository revision: e00f882905db2ac6ffd1ae58b04fa335b38f489c
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101003
System Description: Parabola GNU/Linux-libre

Configured using:
 'configure --with-x-toolkit=lucid'

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 XAW3D XDBE XIM XINPUT2 XPM LUCID ZLIB

Important settings:
  value of $LC_ALL: en_US.UTF-8
  value of $LANG: de_DE.UTF-8
  value of $XMODIFIERS: @im=exwm-xim
  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 puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search time-date subr-x mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils rmc 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 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
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 x-toolkit
xinput2 x multi-tty make-network-process emacs)

Memory information:
((conses 16 40461 8316)
 (symbols 48 5614 3)
 (strings 32 15453 1845)
 (string-bytes 1 479712)
 (vectors 16 10346)
 (vector-slots 8 157393 12635)
 (floats 8 23 17)
 (intervals 56 246 0)
 (buffers 992 11))

-- 
Jean

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