bug#50581: 27.2.50; Tramp fails to (un)compress directories

[Tino Calancha <tino.calancha@gmail.com>]

X-Debbugs-Cc: michael.albinus@gmx.de, uyennhi.qm@gmail.com

Hi Michael,

AFAICS, it only fails for the case of directories (normal files are handled fine).

### Emacs -Q recipe ###

$ src/emacs -Q /sudo::/tmp
+ foo RET
Z

;; Failed to (un)compress /sudo:root@localhost.example.com:/tmp/tramp-test/foo




In GNU Emacs 27.2.50 (build 1, x86_64-pc-linux-gnu, X toolkit, Xaw scroll bars)
 of 2021-09-14 built on localhost.example.com
Repository revision: d7f4cc0974645cc6a295740afe85c6e21d956119
Repository branch: emacs-27
Windowing system distributor 'The X.Org Foundation', version 11.0.12013000
System Description: openSUSE Tumbleweed

Recent messages:
Tramp: Opening connection for root@localhost.example.com using sudo...
Tramp: Sending command ‘exec sudo -u root -s -H -p P""a""s""s""w""o""r""d"": /bin/sh ’
Tramp: Waiting for prompts from remote shell...
Tramp: Sending Password
Tramp: Waiting for prompts from remote shell...done
Tramp: Found remote shell prompt on ‘localhost.example.com’
Tramp: Opening connection for root@localhost.example.com using sudo...done
Compress or uncompress foo? (y or n) y
Compressing /sudo:root@localhost.example.com:/tmp/foo...done
Failed to (un)compress /sudo:root@localhost.example.com:/tmp/foo

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

Configured features:
XPM JPEG TIFF GIF PNG SOUND DBUS GSETTINGS GLIB NOTIFY INOTIFY
LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ XFT ZLIB TOOLKIT_SCROLL_BARS
LUCID X11 XDBE XIM MODULES THREADS PDUMPER GMP

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

Major mode: Dired by name

Minor modes in effect:
  shell-dirtrack-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
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny rfc822 mml easymenu
mml-sec epa derived epg epg-config gnus-util rmail rmail-loaddefs
text-property-search mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils dired-aux dired dired-loaddefs tramp-cache
tramp-sh tramp tramp-loaddefs trampver tramp-integration files-x
tramp-compat shell pcomplete comint ansi-color ring parse-time iso8601
time-date ls-lisp format-spec auth-source cl-seq eieio eieio-core
cl-macs eieio-loaddefs cl-loaddefs cl-lib password-cache json subr-x map
seq byte-opt gv bytecomp byte-compile cconv 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 tab-bar menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame minibuffer 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 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 threads dbusbind inotify dynamic-setting system-font-setting
font-render-setting x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 67680 8068)
 (symbols 48 8193 1)
 (strings 32 25787 2051)
 (string-bytes 1 907396)
 (vectors 16 14425)
 (vector-slots 8 183921 10206)
 (floats 8 42 32)
 (intervals 56 701 289)
 (buffers 1000 14))