Sync with Tramp 2.4.5-pre

* doc/misc/tramp.texi: Adapt Tramp and Emacs version numbers.
(Remote processes): Describe `process-file-return-signal-string'
and $INSIDE_EMACS.
(Frequently Asked Questions): Mention Emacs 28.
Describe `tramp-smb-options'.

* doc/misc/trampver.texi: Change version to "2.4.5-pre".

* lisp/net/tramp-adb.el (process-file-return-signal-string): Declare.
(tramp-adb-handle-write-region): Flush the cache after the file
has been written.
(tramp-adb-handle-set-file-modes, tramp-adb-handle-set-file-times):
Add optional _FLAG.
(tramp-adb-handle-copy-file, tramp-adb-handle-rename-file)
(tramp-adb-handle-process-file): Use `tramp-file-local-name'.
(tramp-adb-get-signal-strings): New defun.
(tramp-adb-handle-process-file): Use it.
(tramp-adb-handle-make-process): Implement `stderr'.  Use
`insert-file-contents-literally'.
(tramp-adb-send-command-and-check): Add optional argument
EXIT-STATUS.
(tramp-adb-handle-process-file): Use it.

* lisp/net/tramp-archive.el (tramp-archive-file-name-handler):
Increase `max-specpdl-size' temporarily.

* lisp/net/tramp-cache.el (top):
Use `insert-file-contents-literally'.

* lisp/net/tramp-cmds.el (tramp-rename-files):
Use `tramp-file-local-name'.

* lisp/net/tramp-gvfs.el (tramp-gvfs-enabled): Prevent crash for
older Emacsen.
(top): Adapt `tramp-gvfs-unload-hook'.
(tramp-gvfs-handle-file-system-info): Fix error.
(tramp-gvfs-handle-set-file-modes, tramp-gvfs-handle-set-file-times):
Add optional _FLAG.

* lisp/net/tramp-rclone.el (tramp-rclone-flush-directory-cache):
Fix a problem with older Emacsen.

* lisp/net/tramp-sh.el (process-file-return-signal-string): Declare.
(tramp-sh-extra-args): Add "-noediting" as bash arg.
(tramp-hexdump-encode, tramp-hexdump-awk-encode)
(tramp-od-encode, tramp-od-awk-encode): New defconst.
(tramp-awk-encode, tramp-awk-decode): Adapt.
(tramp-awk-coding-test): Remove.
(tramp-remote-coding-commands): Add hexdump/awk encoding.  (Bug#35639)
(tramp-find-inline-encoding): Adapt handling of awk, hexdump and od.
(tramp-get-remote-busybox, tramp-get-remote-awk)
(tramp-get-remote-hexdump, tramp-get-remote-od): New defuns.
(tramp-sh-handle-make-symbolic-link):
(tramp-do-copy-or-rename-file-directly)
(tramp-sh-handle-process-file, tramp-set-remote-path)
(tramp-find-inline-encoding, tramp-get-remote-touch):
Use `tramp-file-local-name'.
(tramp-do-file-attributes-with-stat): Simplify shell command.
Suppress errors (interpret as nil).
(tramp-sh-handle-set-file-modes, tramp-sh-handle-set-file-times):
Add optional _FLAG.
(tramp-sh-handle-make-process): Do not visit with
`insert-file-contents'.  Delete tmp file only if exists.  Support
`stderr' as file name.  Delete temporary stderr file.  Flush
connection properties in time.
(tramp-sh-get-signal-strings): New defun.
(tramp-sh-handle-process-file): Use it.
(tramp-sh-handle-write-region): Copy to temp file only if FILENAME
exists.  (Bug#40156)
(tramp-set-remote-path): Send the command in several chunks if it
is too large.  (Bug#42538)
(tramp-open-connection-setup-interactive-shell): Move up "set +o
vi +o emacs" command.   (Bug#39399)
(tramp-send-command-and-read): Suppress `signal-hook-function'
when reading expression.
(tramp-send-command-and-check): Add optional argument EXIT-STATUS.
(tramp-sh-handle-process-file): Use it.  (Bug#41099)

* lisp/net/tramp-smb.el (tramp-smb-conf): Fix docstring.
(tramp-smb-options): New defcustom.
(tramp-smb-handle-copy-directory, tramp-smb-handle-file-acl)
(tramp-smb-handle-set-file-acl, tramp-smb-maybe-open-connection):
Use it.
(tramp-smb-errors): Add "NT_STATUS_INVALID_PARAMETER".
(tramp-smb-handle-make-symbolic-link)
(tramp-smb-handle-process-file): Use `tramp-file-local-name'.

* lisp/net/tramp-sudoedit.el (tramp-sudoedit-do-copy-or-rename-file):
(tramp-sudoedit-handle-set-file-uid-gid):
Use `tramp-unquote-file-local-name'.
(tramp-sudoedit-handle-make-symbolic-link):
Use `tramp-file-local-name'.
(tramp-sudoedit-handle-file-system-info): Fix a scoping error.
(tramp-sudoedit-handle-set-file-modes):
(tramp-sudoedit-handle-set-file-times): Add optional _FLAG.

* lisp/net/tramp.el: Bump version to 2.4.5-pre.
(tramp-file-local-name, tramp-unquote-file-local-name): New defuns.
(tramp-set-connection-local-variables-for-buffer)
(tramp-equal-remote, tramp-handle-make-auto-save-file-name):
Use `tramp-tramp-file-p'.
(tramp-parse-file): Use `insert-file-contents-literally'.
(tramp-handle-file-modes, tramp-handle-file-times):
Add optional _FLAG.
(tramp-handle-shell-command): Fix `window-start' in output buffer.
(Bug#39171)
Handle `shell-command-dont-erase-buffer'.  (Bug#39067)
Reorganize error-buffer handling.  Set `default-directory'.
(Bug#39253)
(tramp-handle-shell-command, tramp-handle-start-file-process):
Implement asynchronous `error-buffer'.
(tramp-action-process-alive): Read pending output.
(tramp-read-passwd): Use `tramp-compat-temporary-file-directory'.
(Bug#39389, Bug#39489)
(tramp-interrupt-process): Improve command.

* lisp/net/trampver.el: Change version to "2.4.5-pre".
(tramp-repository-branch, tramp-repository-version):
Bind `debug-on-error' to nil.

* test/lisp/net/tramp-tests.el (tramp-get-remote-gid)
(process-file-return-signal-string)
(shell-command-dont-erase-buffer): Declare.
(tramp-test10-write-region, tramp-test28-process-file)
(tramp-test29-start-file-process, tramp-test30-make-process)
(tramp-test31-interrupt-process, tramp-test32-shell-command):
Extend test.
(tramp-test10-write-region, tramp-test21-file-links): Use function
symbols.
(tramp-test18-file-attributes): Check `file-ownership-preserved-p'
only if possible.
(tramp--test-async-shell-command): New defun.
(tramp--test-shell-command-to-string-asynchronously): Use it.
(tramp-test32-shell-command-dont-erase-buffer): New test.

12 files changed, 625 insertions, 250 deletions

diff --git a/lisp/net/tramp-adb.el b/lisp/net/tramp-adb.el
index 5cfcb81708f..0efe055b084 100644
--- a/lisp/net/tramp-adb.el
+++ b/lisp/net/tramp-adb.el
@@ -35,6 +35,8 @@
 
 (require 'tramp)
 
+(defvar process-file-return-signal-string)
+
 ;;;###tramp-autoload
 (defcustom tramp-adb-program "adb"
   "Name of the Android Debug Bridge program."
@@ -631,9 +633,6 @@ But handle the case, if the \"test\" command is not available."
 		     (format "File %s exists; overwrite anyway? " filename)))))
       (tramp-error v 'file-already-exists filename))
 
-    ;; We must also flush the cache of the directory, because
-    ;; `file-attributes' reads the values from there.
-    (tramp-flush-file-properties v localname)
     (let* ((curbuf (current-buffer))
 	   (tmpfile (tramp-compat-make-temp-file filename)))
       (when (and append (file-exists-p filename))
@@ -650,6 +649,10 @@ But handle the case, if the \"test\" command is not available."
 	      (tramp-error v 'file-error "Cannot write: `%s'" filename))
 	  (delete-file tmpfile)))
 
+      ;; We must also flush the cache of the directory, because
+      ;; `file-attributes' reads the values from there.
+      (tramp-flush-file-properties v localname)
+
       (unless (equal curbuf (current-buffer))
 	(tramp-error
 	 v 'file-error
@@ -667,13 +670,13 @@ But handle the case, if the \"test\" command is not available."
 	(tramp-message v 0 "Wrote %s" filename))
       (run-hooks 'tramp-handle-write-region-hook))))
 
-(defun tramp-adb-handle-set-file-modes (filename mode)
+(defun tramp-adb-handle-set-file-modes (filename mode &optional _flag)
   "Like `set-file-modes' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (tramp-flush-file-properties v localname)
     (tramp-adb-send-command-and-check v (format "chmod %o %s" mode localname))))
 
-(defun tramp-adb-handle-set-file-times (filename &optional time)
+(defun tramp-adb-handle-set-file-times (filename &optional time _flag)
   "Like `set-file-times' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (tramp-flush-file-properties v localname)
@@ -725,8 +728,8 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	(with-tramp-progress-reporter
 	    v 0 (format "Copying %s to %s" filename newname)
 	  (if (and t1 t2 (tramp-equal-remote filename newname))
-	      (let ((l1 (tramp-compat-file-local-name filename))
-		    (l2 (tramp-compat-file-local-name newname)))
+	      (let ((l1 (tramp-file-local-name filename))
+		    (l2 (tramp-file-local-name newname)))
 		;; We must also flush the cache of the directory,
 		;; because `file-attributes' reads the values from
 		;; there.
@@ -809,8 +812,8 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	  (if (and t1 t2
 		   (tramp-equal-remote filename newname)
 		   (not (file-directory-p filename)))
-	      (let ((l1 (tramp-compat-file-local-name filename))
-		    (l2 (tramp-compat-file-local-name newname)))
+	      (let ((l1 (tramp-file-local-name filename))
+		    (l2 (tramp-file-local-name newname)))
 		;; We must also flush the cache of the directory, because
 		;; `file-attributes' reads the values from there.
 		(tramp-flush-file-properties v l1)
@@ -828,6 +831,33 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	     filename newname ok-if-already-exists 'keep-time 'preserve-uid-gid)
 	    (delete-file filename)))))))
 
+(defun tramp-adb-get-signal-strings (vec)
+  "Strings to return by `process-file' in case of signals."
+  (with-tramp-connection-property vec "signal-strings"
+    (let ((default-directory (tramp-make-tramp-file-name vec 'localname))
+	  ;; `shell-file-name' and `shell-command-switch' are needed
+	  ;; for Emacs < 27.1, which doesn't support connection-local
+	  ;; variables in `shell-command'.
+	  (shell-file-name "/system/bin/sh")
+	  (shell-command-switch "-c")
+	  process-file-return-signal-string signals result)
+      (dotimes (i 128) (push (format "Signal %d" i) result))
+      (setq result (reverse result)
+	    signals (split-string
+		     (shell-command-to-string "COLUMNS=40 kill -l") "\n" 'omit))
+      (setcar result 0)
+      (dolist (line signals)
+	(when (string-match
+	       (concat
+		"^[[:space:]]*\\([[:digit:]]+\\)"
+		"[[:space:]]+\\S-+[[:space:]]+"
+		"\\([[:alpha:]].*\\)$")
+	       line)
+	  (setcar
+	   (nthcdr (string-to-number (match-string 1 line)) result)
+	   (match-string 2 line))))
+      result)))
+
 (defun tramp-adb-handle-process-file
   (program &optional infile destination display &rest args)
   "Like `process-file' for Tramp files."
@@ -846,7 +876,7 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	(setq infile (expand-file-name infile))
 	(if (tramp-equal-remote default-directory infile)
 	    ;; INFILE is on the same remote host.
-	    (setq input (with-parsed-tramp-file-name infile nil localname))
+	    (setq input (tramp-file-local-name infile))
 	  ;; INFILE must be copied to remote host.
 	  (setq input (tramp-make-tramp-temp-file v)
 		tmpinput (tramp-make-tramp-file-name v input))
@@ -877,8 +907,7 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	  (setcar (cdr destination) (expand-file-name (cadr destination)))
 	  (if (tramp-equal-remote default-directory (cadr destination))
 	      ;; stderr is on the same remote host.
-	      (setq stderr (with-parsed-tramp-file-name
-			       (cadr destination) nil localname))
+	      (setq stderr (tramp-file-local-name (cadr destination)))
 	    ;; stderr must be copied to remote host.  The temporary
 	    ;; file must be deleted after execution.
 	    (setq stderr (tramp-make-tramp-temp-file v)
@@ -895,14 +924,13 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
       ;; it.  Call it in a subshell, in order to preserve working
       ;; directory.
       (condition-case nil
-	  (progn
-	    (setq ret
-		  (if (tramp-adb-send-command-and-check
-		       v
-		       (format "(cd %s; %s)"
-			       (tramp-shell-quote-argument localname) command))
-		      ;; Set return status accordingly.
-		      0 1))
+	  (unwind-protect
+	      (setq ret (tramp-adb-send-command-and-check
+			 v (format
+			    "(cd %s; %s)"
+			    (tramp-shell-quote-argument localname) command)
+			 t))
+	    (unless (natnump ret) (setq ret 1))
 	    ;; We should add the output anyway.
 	    (when outbuf
 	      (with-current-buffer outbuf
@@ -918,6 +946,12 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	 (kill-buffer (tramp-get-connection-buffer v))
 	 (setq ret 1)))
 
+      ;; Handle signals.  `process-file-return-signal-string' exists
+      ;; since Emacs 28.1.
+      (when (and (bound-and-true-p process-file-return-signal-string)
+		 (natnump ret) (> ret 128))
+	(setq ret (nth (- ret 128) (tramp-adb-get-signal-strings v))))
+
       ;; Provide error file.
       (when tmpstderr (rename-file tmpstderr (cadr destination) t))
 
@@ -936,6 +970,8 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 ;; We use BUFFER also as connection buffer during setup.  Because of
 ;; this, its original contents must be saved, and restored once
 ;; connection has been setup.
+;; The complete STDERR buffer is available only when the process has
+;; terminated.
 (defun tramp-adb-handle-make-process (&rest args)
   "Like `make-process' for Tramp files."
   (when args
@@ -969,17 +1005,29 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	  (signal 'wrong-type-argument (list #'functionp sentinel)))
 	(unless (or (null stderr) (bufferp stderr) (stringp stderr))
 	  (signal 'wrong-type-argument (list #'stringp stderr)))
+	(when (and (stringp stderr) (tramp-tramp-file-p stderr)
+		   (not (tramp-equal-remote default-directory stderr)))
+	  (signal 'file-error (list "Wrong stderr" stderr)))
 
 	(let* ((buffer
 		(if buffer
 		    (get-buffer-create buffer)
 		  ;; BUFFER can be nil.  We use a temporary buffer.
 		  (generate-new-buffer tramp-temp-buffer-name)))
+	       ;; STDERR can also be a file name.
+	       (tmpstderr
+		(and stderr
+		     (if (and (stringp stderr) (tramp-tramp-file-p stderr))
+			 (tramp-unquote-file-local-name stderr)
+		       (tramp-make-tramp-temp-file v))))
+	       (remote-tmpstderr
+		(and tmpstderr (tramp-make-tramp-file-name v tmpstderr)))
 	       (program (car command))
 	       (args (cdr command))
 	       (command
-		(format "cd %s && exec %s"
+		(format "cd %s && exec %s %s"
 			(tramp-shell-quote-argument localname)
+			(if tmpstderr (format "2>'%s'" tmpstderr) "")
 			(mapconcat #'tramp-shell-quote-argument
 				   (cons program args) " ")))
 	       (tramp-process-connection-type
@@ -1029,6 +1077,18 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 			(ignore-errors
 			  (set-process-query-on-exit-flag p (null noquery))
 			  (set-marker (process-mark p) (point)))
+			;; We must flush them here already; otherwise
+			;; `rename-file', `delete-file' or
+			;; `insert-file-contents' will fail.
+			(tramp-flush-connection-property v "process-name")
+			(tramp-flush-connection-property v "process-buffer")
+			;; Copy tmpstderr file.
+			(when (and (stringp stderr)
+				   (not (tramp-tramp-file-p stderr)))
+			  (add-function
+			   :after (process-sentinel p)
+			   (lambda (_proc _msg)
+			     (rename-file remote-tmpstderr stderr))))
 			;; Read initial output.  Remove the first line,
 			;; which is the command echo.
 			(while
@@ -1037,6 +1097,23 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 			      (not (re-search-forward "[\n]" nil t)))
 			  (tramp-accept-process-output p 0))
 			(delete-region (point-min) (point))
+			;; Provide error buffer.  This shows only
+			;; initial error messages; messages arriving
+			;; later on will be inserted when the process
+			;; is deleted.  The temporary file will exist
+			;; until the process is deleted.
+			(when (bufferp stderr)
+			  (with-current-buffer stderr
+			    (insert-file-contents-literally
+			     remote-tmpstderr 'visit))
+			  ;; Delete tmpstderr file.
+			  (add-function
+			   :after (process-sentinel p)
+			   (lambda (_proc _msg)
+			     (with-current-buffer stderr
+			       (insert-file-contents-literally
+				remote-tmpstderr 'visit nil nil 'replace))
+			     (delete-file remote-tmpstderr))))
 			;; Return process.
 			p))))
 
@@ -1062,7 +1139,7 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	  (read (current-buffer)))
 	":" 'omit)))
    ;; The equivalent to `exec-directory'.
-   `(,(tramp-compat-file-local-name default-directory))))
+   `(,(tramp-file-local-name (expand-file-name default-directory)))))
 
 (defun tramp-adb-get-device (vec)
   "Return full host name from VEC to be used in shell execution.
@@ -1146,11 +1223,14 @@ This happens for Android >= 4.0."
 	(while (re-search-forward "\r+$" nil t)
 	  (replace-match "" nil nil))))))
 
-(defun tramp-adb-send-command-and-check (vec command)
+(defun tramp-adb-send-command-and-check (vec command &optional exit-status)
   "Run COMMAND and check its exit status.
 Sends `echo $?' along with the COMMAND for checking the exit
 status.  If COMMAND is nil, just sends `echo $?'.  Returns nil if
-the exit status is not equal 0, and t otherwise."
+the exit status is not equal 0, and t otherwise.
+
+Optional argument EXIT-STATUS, if non-nil, triggers the return of
+the exit status."
   (tramp-adb-send-command
    vec (if command
 	   (format "%s; echo tramp_exit_status $?" command)
@@ -1161,7 +1241,9 @@ the exit status is not equal 0, and t otherwise."
        vec 'file-error "Couldn't find exit status of `%s'" command))
     (skip-chars-forward "^ ")
     (prog1
-	(zerop (read (current-buffer)))
+	(if exit-status
+	    (read (current-buffer))
+	  (zerop (read (current-buffer))))
       (let ((inhibit-read-only t))
 	(delete-region (match-beginning 0) (point-max))))))
 
diff --git a/lisp/net/tramp-archive.el b/lisp/net/tramp-archive.el
index b9bf6180a5d..611247ef2cb 100644
--- a/lisp/net/tramp-archive.el
+++ b/lisp/net/tramp-archive.el
@@ -109,7 +109,7 @@
 
 (eval-when-compile (require 'cl-lib))
 ;; Sometimes, compilation fails with "Variable binding depth exceeds
-;; max-specpdl-size".
+;; max-specpdl-size".  Shall be fixed in Emacs 27.
 (eval-and-compile
   (let ((max-specpdl-size (* 2 max-specpdl-size))) (require 'tramp-gvfs)))
 
@@ -318,7 +318,10 @@ arguments to pass to the OPERATION."
 
       (let* ((filename (apply #'tramp-archive-file-name-for-operation
 			      operation args))
-	     (archive (tramp-archive-file-name-archive filename)))
+	     (archive (tramp-archive-file-name-archive filename))
+	     ;; Sometimes, it fails with "Variable binding depth exceeds
+	     ;; max-specpdl-size".  Shall be fixed in Emacs 27.
+	     (max-specpdl-size (* 2 max-specpdl-size)))
 
         ;; `filename' could be a quoted file name.  Or the file
         ;; archive could be a directory, see Bug#30293.
diff --git a/lisp/net/tramp-cache.el b/lisp/net/tramp-cache.el
index 62e25fa1f08..0f2d7a1800f 100644
--- a/lisp/net/tramp-cache.el
+++ b/lisp/net/tramp-cache.el
@@ -514,7 +514,7 @@ for all methods.  Resulting data are derived from connection history."
 	   tramp-cache-read-persistent-data)
   (condition-case err
       (with-temp-buffer
-	(insert-file-contents tramp-persistency-file-name)
+	(insert-file-contents-literally tramp-persistency-file-name)
 	(let ((list (read (current-buffer)))
 	      (tramp-verbose 0)
 	      element key item)
diff --git a/lisp/net/tramp-cmds.el b/lisp/net/tramp-cmds.el
index 9d1025b9072..b4dca2321c1 100644
--- a/lisp/net/tramp-cmds.el
+++ b/lisp/net/tramp-cmds.el
@@ -358,7 +358,7 @@ The remote connection identified by SOURCE is flushed by
 
   ;; Append local file name if none is specified.
   (when (string-equal (file-remote-p target) target)
-    (setq target (concat target (file-remote-p source 'localname))))
+    (setq target (concat target (tramp-file-local-name source))))
   ;; Make them directory names.
   (setq source (directory-file-name source)
 	target (directory-file-name target))
diff --git a/lisp/net/tramp-compat.el b/lisp/net/tramp-compat.el
index 723b8cfa1e3..3f25afedb99 100644
--- a/lisp/net/tramp-compat.el
+++ b/lisp/net/tramp-compat.el
@@ -41,6 +41,7 @@
 (require 'shell)
 (require 'subr-x)
 
+;; `temporary-file-directory' as function is introduced with Emacs 26.1.
 (declare-function tramp-handle-temporary-file-directory "tramp")
 
 ;; For not existing functions, obsolete functions, or functions with a
diff --git a/lisp/net/tramp-gvfs.el b/lisp/net/tramp-gvfs.el
index 34a234c47f0..ddb535fea6e 100644
--- a/lisp/net/tramp-gvfs.el
+++ b/lisp/net/tramp-gvfs.el
@@ -121,7 +121,10 @@
 	 (autoload 'zeroconf-init "zeroconf")
 	 (tramp-compat-funcall 'dbus-get-unique-name :system)
 	 (tramp-compat-funcall 'dbus-get-unique-name :session)
-	 (or (tramp-compat-process-running-p "gvfs-fuse-daemon")
+	 (or ;; Until Emacs 25, `process-attributes' could crash Emacs
+	     ;; for some processes.  Better we don't check.
+	     (<= emacs-major-version 25)
+	     (tramp-compat-process-running-p "gvfs-fuse-daemon")
 	     (tramp-compat-process-running-p "gvfsd-fuse"))))
   "Non-nil when GVFS is available.")
 
@@ -728,6 +731,10 @@ is no information where to trace the message.")
     (tramp-error tramp-gvfs-dbus-event-vector 'file-error "%s" (cadr err))))
 
 (add-hook 'dbus-event-error-functions #'tramp-gvfs-dbus-event-error)
+(add-hook
+ 'tramp-gvfs-unload-hook
+ (lambda ()
+   (remove-hook 'dbus-event-error-functions #'tramp-gvfs-dbus-event-error)))
 
 
 ;; File name primitives.
@@ -1301,10 +1308,11 @@ If FILE-SYSTEM is non-nil, return file system attributes."
 	   (size (cdr (assoc "filesystem::size" attr)))
 	   (used (cdr (assoc "filesystem::used" attr)))
 	   (free (cdr (assoc "filesystem::free" attr))))
-      (when (and (stringp size) (stringp used) (stringp free))
-	(list (string-to-number size)
-	      (- (string-to-number size) (string-to-number used))
-	      (string-to-number free))))))
+      (when (or size used free)
+	(list (string-to-number (or size "0"))
+	      (string-to-number (or free "0"))
+	      (- (string-to-number (or size "0"))
+		 (string-to-number (or used "0"))))))))
 
 (defun tramp-gvfs-handle-make-directory (dir &optional parents)
   "Like `make-directory' for Tramp files."
@@ -1341,7 +1349,7 @@ If FILE-SYSTEM is non-nil, return file system attributes."
     (tramp-run-real-handler
      #'rename-file (list filename newname ok-if-already-exists))))
 
-(defun tramp-gvfs-handle-set-file-modes (filename mode)
+(defun tramp-gvfs-handle-set-file-modes (filename mode &optional _flag)
   "Like `set-file-modes' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (tramp-flush-file-properties v localname)
@@ -1350,7 +1358,7 @@ If FILE-SYSTEM is non-nil, return file system attributes."
      (tramp-gvfs-url-file-name (tramp-make-tramp-file-name v))
      "unix::mode" (number-to-string mode))))
 
-(defun tramp-gvfs-handle-set-file-times (filename &optional time)
+(defun tramp-gvfs-handle-set-file-times (filename &optional time _flag)
   "Like `set-file-times' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (tramp-flush-file-properties v localname)
diff --git a/lisp/net/tramp-rclone.el b/lisp/net/tramp-rclone.el
index 9f539850139..fcbd2010a26 100644
--- a/lisp/net/tramp-rclone.el
+++ b/lisp/net/tramp-rclone.el
@@ -478,7 +478,18 @@ file names."
 	   (with-tramp-connection-property
 	       (tramp-get-connection-process vec) "rclone-pid"
 	     (catch 'pid
-	       (dolist (pid (list-system-processes)) ;; "pidof rclone" ?
+	       (dolist
+		   (pid
+		    ;; Until Emacs 25, `process-attributes' could
+		    ;; crash Emacs for some processes.  So we use
+		    ;; "pidof", which might not work everywhere.
+		    (if (<= emacs-major-version 25)
+			(let ((default-directory temporary-file-directory))
+			  (mapcar
+			   #'string-to-number
+			   (split-string
+			    (shell-command-to-string "pidof rclone"))))
+		      (list-system-processes)))
 		 (and (string-match-p
 		       (regexp-quote
 			(format "rclone mount %s:" (tramp-file-name-host vec)))
@@ -564,7 +575,7 @@ connection if a previous connection has died for some reason."
 		 ,(tramp-rclone-mount-point vec)
 		 ;; This could be nil.
 		 ,(tramp-get-method-parameter vec 'tramp-mount-args))))
-	(while (not (file-exists-p (tramp-make-tramp-file-name vec 'localname)))
+	(while (not (file-exists-p (tramp-make-tramp-file-name vec 'noloc)))
 	  (tramp-cleanup-connection vec 'keep-debug 'keep-password))
 
 	;; Mark it as connected.
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index af97328b3d3..9e8a3168fd7 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -36,6 +36,7 @@
 
 (declare-function dired-remove-file "dired-aux")
 (defvar dired-compress-file-suffixes)
+(defvar process-file-return-signal-string)
 (defvar vc-handled-backends)
 (defvar vc-bzr-program)
 (defvar vc-git-program)
@@ -537,12 +538,13 @@ based on the Tramp and Emacs versions, and should not be set here."
 
 ;;;###tramp-autoload
 (defcustom tramp-sh-extra-args
-  '(("/bash\\'" . "-norc -noprofile")
+  '(("/bash\\'" . "-noediting -norc -noprofile")
     ("/zsh\\'" . "-f +Z -V"))
   "Alist specifying extra arguments to pass to the remote shell.
 Entries are (REGEXP . ARGS) where REGEXP is a regular expression
 matching the shell file name and ARGS is a string specifying the
-arguments.
+arguments.  These arguments shall disable line editing, see
+`tramp-open-shell'.
 
 This variable is only used when Tramp needs to start up another shell
 for tilde expansion.  The extra arguments should typically prevent the
@@ -866,8 +868,12 @@ Escape sequence %s is replaced with name of Perl binary.")
   "Perl program to use for decoding a file.
 Escape sequence %s is replaced with name of Perl binary.")
 
+(defconst tramp-hexdump-encode "%h -v -e '16/1 \" %%02x\" \"\\n\"'"
+  "`hexdump' program to use for encoding a file.
+This string is passed to `format', so percent characters need to be doubled.")
+
 (defconst tramp-awk-encode
-  "od -v -t x1 -A n | busybox awk '\\
+  "%a '\\
 BEGIN {
   b64 = \"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\"
   b16 = \"0123456789abcdef\"
@@ -897,11 +903,25 @@ END {
   }
   printf tail
 }'"
-  "Awk program to use for encoding a file.
+  "`awk' program to use for encoding a file.
+This string is passed to `format', so percent characters need to be doubled.")
+
+(defconst tramp-hexdump-awk-encode
+  (format "%s | %s" tramp-hexdump-encode tramp-awk-encode)
+  "`hexdump' / `awk' pipe to use for encoding a file.
+This string is passed to `format', so percent characters need to be doubled.")
+
+(defconst tramp-od-encode "%o -v -t x1 -A n"
+  "`od' program to use for encoding a file.
+This string is passed to `format', so percent characters need to be doubled.")
+
+(defconst tramp-od-awk-encode
+  (format "%s | %s" tramp-od-encode tramp-awk-encode)
+  "`od' / `awk' pipe to use for encoding a file.
 This string is passed to `format', so percent characters need to be doubled.")
 
 (defconst tramp-awk-decode
-  "busybox awk '\\
+  "%a '\\
 BEGIN {
   b64 = \"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/\"
 }
@@ -926,12 +946,6 @@ BEGIN {
   "Awk program to use for decoding a file.
 This string is passed to `format', so percent characters need to be doubled.")
 
-(defconst tramp-awk-coding-test
-  "test -c /dev/zero && \
-od -v -t x1 -A n </dev/null && \
-busybox awk '{}' </dev/null"
-  "Test command for checking `tramp-awk-encode' and `tramp-awk-decode'.")
-
 (defconst tramp-vc-registered-read-file-names
   "echo \"(\"
 while read file; do
@@ -1051,9 +1065,7 @@ component is used as the target of the symlink."
       (let ((non-essential t))
 	(when (and (tramp-tramp-file-p target)
 		   (tramp-file-name-equal-p v (tramp-dissect-file-name target)))
-	  (setq target
-		(tramp-file-name-localname
-		 (tramp-dissect-file-name (expand-file-name target))))))
+	  (setq target (tramp-file-local-name (expand-file-name target)))))
 
       ;; If TARGET is still remote, quote it.
       (if (tramp-tramp-file-p target)
@@ -1263,8 +1275,8 @@ component is used as the target of the symlink."
 (defun tramp-do-file-attributes-with-ls (vec localname &optional id-format)
   "Implement `file-attributes' for Tramp files using the ls(1) command."
   (let (symlinkp dirp
-		 res-inode res-filemodes res-numlinks
-		 res-uid res-gid res-size res-symlink-target)
+	res-inode res-filemodes res-numlinks
+	res-uid res-gid res-size res-symlink-target)
     (tramp-message vec 5 "file attributes with ls: %s" localname)
     ;; We cannot send all three commands combined, it could exceed
     ;; NAME_MAX or PATH_MAX.  Happened on macOS, for example.
@@ -1368,18 +1380,11 @@ component is used as the target of the symlink."
    (format
     (eval-when-compile
       (concat
-       ;; On Opsware, pdksh (which is the true name of ksh there)
-       ;; doesn't parse correctly the sequence "((".  Therefore, we
-       ;; add a space.  Apostrophes in the stat output are masked as
+       ;; Apostrophes in the stat output are masked as
        ;; `tramp-stat-marker', in order to make a proper shell escape
        ;; of them in file names.
-       "( (%s %s || %s -h %s) && (%s -c "
-       "'((%s%%N%s) %%h %s %s %%X %%Y %%Z %%s %s%%A%s t %%i -1)' "
-       "%s | sed -e 's/\"/\\\\\"/g' -e 's/%s/\"/g') || echo nil)"))
-    (tramp-get-file-exists-command vec)
-    (tramp-shell-quote-argument localname)
-    (tramp-get-test-command vec)
-    (tramp-shell-quote-argument localname)
+       "(%s -c '((%s%%N%s) %%h %s %s %%X %%Y %%Z %%s %s%%A%s t %%i -1)' %s |"
+       " sed -e 's/\"/\\\\\"/g' -e 's/%s/\"/g')"))
     (tramp-get-remote-stat vec)
     tramp-stat-marker tramp-stat-marker
     (if (eq id-format 'integer)
@@ -1390,7 +1395,8 @@ component is used as the target of the symlink."
       (eval-when-compile (concat tramp-stat-marker "%G" tramp-stat-marker)))
     tramp-stat-marker tramp-stat-marker
     (tramp-shell-quote-argument localname)
-    tramp-stat-quoted-marker)))
+    tramp-stat-quoted-marker)
+   'noerror))
 
 (defun tramp-sh-handle-set-visited-file-modtime (&optional time-list)
   "Like `set-visited-file-modtime' for Tramp files."
@@ -1468,7 +1474,7 @@ of."
 	     ;; only if that agrees with the buffer's record.
 	     (t (tramp-compat-time-equal-p mt tramp-time-doesnt-exist)))))))))
 
-(defun tramp-sh-handle-set-file-modes (filename mode)
+(defun tramp-sh-handle-set-file-modes (filename mode &optional _flag)
   "Like `set-file-modes' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (tramp-flush-file-properties v localname)
@@ -1478,7 +1484,7 @@ of."
      (format "chmod %o %s" mode (tramp-shell-quote-argument localname))
      "Error while changing file's mode %s" filename)))
 
-(defun tramp-sh-handle-set-file-times (filename &optional time)
+(defun tramp-sh-handle-set-file-times (filename &optional time _flag)
   "Like `set-file-times' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (when (tramp-get-remote-touch v)
@@ -2171,8 +2177,8 @@ the uid and gid from FILENAME."
 			    v 'file-error
 			    "Unknown operation `%s', must be `copy' or `rename'"
 			    op))))
-	     (localname1 (tramp-compat-file-local-name filename))
-	     (localname2 (tramp-compat-file-local-name newname))
+	     (localname1 (tramp-file-local-name filename))
+	     (localname2 (tramp-file-local-name newname))
 	     (prefix (file-remote-p (if t1 filename newname)))
              cmd-result)
 	(when (and (eq op 'copy) (file-directory-p filename))
@@ -2796,8 +2802,11 @@ the result will be a local, non-Tramp, file name."
 ;; We use BUFFER also as connection buffer during setup. Because of
 ;; this, its original contents must be saved, and restored once
 ;; connection has been setup.
+;; The complete STDERR buffer is available only when the process has
+;; terminated.
 (defun tramp-sh-handle-make-process (&rest args)
-  "Like `make-process' for Tramp files."
+  "Like `make-process' for Tramp files.
+STDERR can also be a file name."
   (when args
     (with-parsed-tramp-file-name (expand-file-name default-directory) nil
       (let ((name (plist-get args :name))
@@ -2829,14 +2838,23 @@ the result will be a local, non-Tramp, file name."
 	  (signal 'wrong-type-argument (list #'functionp sentinel)))
 	(unless (or (null stderr) (bufferp stderr) (stringp stderr))
 	  (signal 'wrong-type-argument (list #'stringp stderr)))
+	(when (and (stringp stderr) (tramp-tramp-file-p stderr)
+		   (not (tramp-equal-remote default-directory stderr)))
+	  (signal 'file-error (list "Wrong stderr" stderr)))
 
 	(let* ((buffer
 		(if buffer
 		    (get-buffer-create buffer)
 		  ;; BUFFER can be nil.  We use a temporary buffer.
 		  (generate-new-buffer tramp-temp-buffer-name)))
-	       (stderr (and stderr (get-buffer-create stderr)))
-	       (tmpstderr (and stderr (tramp-make-tramp-temp-file v)))
+	       ;; STDERR can also be a file name.
+	       (tmpstderr
+		(and stderr
+		     (if (and (stringp stderr) (tramp-tramp-file-p stderr))
+			 (tramp-unquote-file-local-name stderr)
+		       (tramp-make-tramp-temp-file v))))
+	       (remote-tmpstderr
+		(and tmpstderr (tramp-make-tramp-file-name v tmpstderr)))
 	       (program (car command))
 	       (args (cdr command))
 	       ;; When PROGRAM matches "*sh", and the first arg is
@@ -2965,21 +2983,35 @@ the result will be a local, non-Tramp, file name."
 		      (ignore-errors
 			(set-process-query-on-exit-flag p (null noquery))
 			(set-marker (process-mark p) (point)))
+		      ;; We must flush them here already; otherwise
+		      ;; `rename-file', `delete-file' or
+		      ;; `insert-file-contents' will fail.
+		      (tramp-flush-connection-property v "process-name")
+		      (tramp-flush-connection-property v "process-buffer")
+		      ;; Copy tmpstderr file.
+		      (when (and (stringp stderr)
+				 (not (tramp-tramp-file-p stderr)))
+			(add-function
+			 :after (process-sentinel p)
+			 (lambda (_proc _msg)
+			   (rename-file remote-tmpstderr stderr))))
 		      ;; Provide error buffer.  This shows only
 		      ;; initial error messages; messages arriving
-		      ;; later on shall be inserted by `auto-revert'.
-		      ;; The temporary file will still be existing.
-		      ;; TODO: Write a sentinel, which deletes the
-		      ;; temporary file.
-		      (when tmpstderr
-			;; We must flush them here already; otherwise
-			;; `insert-file-contents' will fail.
-			(tramp-flush-connection-property v "process-name")
-			(tramp-flush-connection-property v "process-buffer")
+		      ;; later on will be inserted when the process is
+		      ;; deleted.  The temporary file will exist until
+		      ;; the process is deleted.
+		      (when (bufferp stderr)
 			(with-current-buffer stderr
-			  (insert-file-contents
-			   (tramp-make-tramp-file-name v tmpstderr) 'visit)
-			  (auto-revert-mode)))
+			  (insert-file-contents-literally remote-tmpstderr))
+			;; Delete tmpstderr file.
+			(add-function
+			 :after (process-sentinel p)
+			 (lambda (_proc _msg)
+			   (when (file-exists-p remote-tmpstderr)
+			     (with-current-buffer stderr
+			       (insert-file-contents-literally
+				remote-tmpstderr nil nil nil 'replace))
+			     (delete-file remote-tmpstderr)))))
 		      ;; Return process.
 		      p)))
 
@@ -2992,6 +3024,65 @@ the result will be a local, non-Tramp, file name."
 	      (tramp-flush-connection-property v "process-name")
 	      (tramp-flush-connection-property v "process-buffer"))))))))
 
+(defun tramp-sh-get-signal-strings (vec)
+  "Strings to return by `process-file' in case of signals."
+  (with-tramp-connection-property
+      vec
+      (concat
+       "signal-strings-" (tramp-get-method-parameter vec 'tramp-remote-shell))
+    (let ((default-directory (tramp-make-tramp-file-name vec 'localname))
+	  process-file-return-signal-string signals res result)
+      (setq signals
+	    (append
+	     '(0) (split-string (shell-command-to-string "kill -l") nil 'omit)))
+      ;; Sanity check.  Sometimes, the first entry is "0", although we
+      ;; don't expect it.  Remove it.
+      (when (and (stringp (cadr signals)) (string-equal "0" (cadr signals)))
+	(setcdr signals (cddr signals)))
+      ;; Sanity check.  "kill -l" shall have returned just the signal
+      ;; names.  Some shells don't, like the one in "docker alpine".
+      (let (signal-hook-function)
+	(condition-case nil
+	    (dolist (sig (cdr signals))
+	      (unless (string-match-p "^[[:alnum:]+-]+$" sig)
+		(error nil)))
+	  (error (setq signals '(0)))))
+      (dotimes (i 128)
+	(push
+	 (cond
+	  ;; Some predefined values, which aren't reported sometimes,
+	  ;; or would raise problems (all Stopped signals).
+	  ((= i 0) 0)
+	  ((string-equal (nth i signals) "HUP") "Hangup")
+	  ((string-equal (nth i signals) "INT") "Interrupt")
+	  ((string-equal (nth i signals) "QUIT") "Quit")
+	  ((string-equal (nth i signals) "STOP") "Stopped (signal)")
+	  ((string-equal (nth i signals) "TSTP") "Stopped")
+	  ((string-equal (nth i signals) "TTIN") "Stopped (tty input)")
+	  ((string-equal (nth i signals) "TTOU") "Stopped (tty output)")
+	  (t (setq res
+		   (if (null (nth i signals))
+		       ""
+		     (tramp-send-command
+		      vec
+		      (format
+		       "%s %s %s"
+		       (tramp-get-method-parameter vec 'tramp-remote-shell)
+		       (mapconcat
+			#'identity
+			(tramp-get-method-parameter vec 'tramp-remote-shell-args)
+			" ")
+		       (tramp-shell-quote-argument (format "kill -%d $$" i))))
+		     (with-current-buffer (tramp-get-connection-buffer vec)
+		       (goto-char (point-min))
+		       (buffer-substring (point-at-bol) (point-at-eol)))))
+	     (if (string-equal res "")
+		 (format "Signal %d" i)
+	       res)))
+	 result))
+      ;; Due to Bug#41287, we cannot add this to the `dotimes' clause.
+      (reverse result))))
+
 (defun tramp-sh-handle-process-file
   (program &optional infile destination display &rest args)
   "Like `process-file' for Tramp files."
@@ -3028,7 +3119,7 @@ the result will be a local, non-Tramp, file name."
 	(setq infile (expand-file-name infile))
 	(if (tramp-equal-remote default-directory infile)
 	    ;; INFILE is on the same remote host.
-	    (setq input (with-parsed-tramp-file-name infile nil localname))
+	    (setq input (tramp-file-local-name infile))
 	  ;; INFILE must be copied to remote host.
 	  (setq input (tramp-make-tramp-temp-file v)
 		tmpinput (tramp-make-tramp-file-name v input 'nohop))
@@ -3059,8 +3150,7 @@ the result will be a local, non-Tramp, file name."
 	  (setcar (cdr destination) (expand-file-name (cadr destination)))
 	  (if (tramp-equal-remote default-directory (cadr destination))
 	      ;; stderr is on the same remote host.
-	      (setq stderr (with-parsed-tramp-file-name
-			       (cadr destination) nil localname))
+	      (setq stderr (tramp-file-local-name (cadr destination)))
 	    ;; stderr must be copied to remote host.  The temporary
 	    ;; file must be deleted after execution.
 	    (setq stderr (tramp-make-tramp-temp-file v)
@@ -3078,13 +3168,12 @@ the result will be a local, non-Tramp, file name."
       ;; directory.
       (condition-case nil
 	  (unwind-protect
-              (setq ret
-		    (if (tramp-send-command-and-check
-			 v (format "cd %s && %s"
-				   (tramp-shell-quote-argument localname)
-				   command)
-			 t t)
-			0 1))
+              (setq ret (tramp-send-command-and-check
+			 v (format
+			    "cd %s && %s"
+			    (tramp-shell-quote-argument localname) command)
+			 t t t))
+	    (unless (natnump ret) (setq ret 1))
 	    ;; We should add the output anyway.
 	    (when outbuf
 	      (with-current-buffer outbuf
@@ -3102,6 +3191,12 @@ the result will be a local, non-Tramp, file name."
 	 (kill-buffer (tramp-get-connection-buffer v))
 	 (setq ret 1)))
 
+      ;; Handle signals.  `process-file-return-signal-string' exists
+      ;; since Emacs 28.1.
+      (when (and (bound-and-true-p process-file-return-signal-string)
+		 (natnump ret) (>= ret 128))
+	(setq ret (nth (- ret 128) (tramp-sh-get-signal-strings v))))
+
       ;; Provide error file.
       (when tmpstderr (rename-file tmpstderr (cadr destination) t))
 
@@ -3122,7 +3217,7 @@ the result will be a local, non-Tramp, file name."
   (append
    (tramp-get-remote-path (tramp-dissect-file-name default-directory))
    ;; The equivalent to `exec-directory'.
-   `(,(tramp-compat-file-local-name default-directory))))
+   `(,(tramp-file-local-name (expand-file-name default-directory)))))
 
 (defun tramp-sh-handle-file-local-copy (filename)
   "Like `file-local-copy' for Tramp files."
@@ -3258,7 +3353,8 @@ the result will be a local, non-Tramp, file name."
 
 	  ;; If `append' is non-nil, we copy the file locally, and let
 	  ;; the native `write-region' implementation do the job.
-	  (when append (copy-file filename tmpfile 'ok))
+	  (when (and append (file-exists-p filename))
+	    (copy-file filename tmpfile 'ok))
 
 	  ;; We say `no-message' here because we don't want the
 	  ;; visited file modtime data to be clobbered from the temp
@@ -3981,23 +4077,30 @@ whether it exists and if so, it is added to the environment
 variable PATH."
   (let ((command
 	 (format
-	  "PATH=%s; export PATH" (string-join (tramp-get-remote-path vec) ":")))
+	  "PATH=%s && export PATH" (string-join (tramp-get-remote-path vec) ":")))
 	(pipe-buf
-	 (or (with-tramp-connection-property vec "pipe-buf"
-	       (tramp-send-command-and-read
-		vec "getconf PIPE_BUF / 2>/dev/null || echo nil" 'noerror))
-	     4096))
-	tmpfile)
+	 (with-tramp-connection-property vec "pipe-buf"
+	   (tramp-send-command-and-read
+	    vec "getconf PIPE_BUF / 2>/dev/null || echo 4096" 'noerror)))
+	tmpfile chunk chunksize)
     (tramp-message vec 5 "Setting $PATH environment variable")
     (if (< (length command) pipe-buf)
 	(tramp-send-command vec command)
-      ;; Use a temporary file.
-      (setq tmpfile
-	    (tramp-make-tramp-file-name vec (tramp-make-tramp-temp-file vec)))
-      (write-region command nil tmpfile)
-      (tramp-send-command
-       vec (format ". %s" (tramp-compat-file-local-name tmpfile)))
-      (delete-file tmpfile))))
+      ;; Use a temporary file.  We cannot use `write-region' because
+      ;; setting the remote path happens in the early connection
+      ;; handshake, and not all external tools are determined yet.
+      (setq command (concat command "\n")
+	    tmpfile (tramp-make-tramp-temp-file vec))
+      (while (not (string-empty-p command))
+	(setq chunksize (min (length command) (/ pipe-buf 2))
+	      chunk (substring command 0 chunksize)
+	      command (substring command chunksize))
+	(tramp-send-command vec (format
+				 "echo -n %s >>%s"
+				 (tramp-shell-quote-argument chunk)
+				 (tramp-shell-quote-argument tmpfile))))
+      (tramp-send-command vec (format ". %s" tmpfile))
+      (tramp-send-command vec (format "rm -f %s" tmpfile)))))
 
 ;; ------------------------------------------------------------
 ;; -- Communication with external shell --
@@ -4069,54 +4172,54 @@ file exists and nonzero exit status otherwise."
 
 (defun tramp-open-shell (vec shell)
   "Open shell SHELL."
+  ;; Find arguments for this shell.
   (with-tramp-progress-reporter
       vec 5 (format-message "Opening remote shell `%s'" shell)
-    ;; Find arguments for this shell.
-    (let ((extra-args (tramp-get-sh-extra-args shell)))
-      ;; doesn't know about and thus /bin/sh will display a strange
-      ;; prompt.  For example, if $PS1 has "${CWD}" in the value, then
-      ;; ksh will display the current working directory but /bin/sh
-      ;; will display a dollar sign.  The following command line sets
-      ;; $PS1 to a sane value, and works under Bourne-ish shells as
-      ;; well as csh-like shells.  We also unset the variable $ENV
-      ;; because that is read by some sh implementations (eg, bash
-      ;; when called as sh) on startup; this way, we avoid the startup
-      ;; file clobbering $PS1.  $PROMPT_COMMAND is another way to set
-      ;; the prompt in /bin/bash, it must be discarded as well.
-      ;; $HISTFILE is set according to `tramp-histfile-override'.
-      ;; $TERM and $INSIDE_EMACS set here to ensure they have the
-      ;; correct values when the shell starts, not just processes
-      ;; run within the shell.  (Which processes include our
-      ;; initial probes to ensure the remote shell is usable.)
-      (tramp-send-command
-       vec (format
-	    (eval-when-compile
-	      (concat
-	       "exec env TERM='%s' INSIDE_EMACS='%s,tramp:%s' "
-	       "ENV=%s %s PROMPT_COMMAND='' PS1=%s PS2='' PS3='' %s %s"))
-            tramp-terminal-type
-            emacs-version tramp-version  ; INSIDE_EMACS
-            (or (getenv-internal "ENV" tramp-remote-process-environment) "")
-	    (if (stringp tramp-histfile-override)
-		(format "HISTFILE=%s"
-			(tramp-shell-quote-argument tramp-histfile-override))
-	      (if tramp-histfile-override
-		  "HISTFILE='' HISTFILESIZE=0 HISTSIZE=0"
-		""))
-	    (tramp-shell-quote-argument tramp-end-of-output)
-	    shell (or extra-args ""))
-       t)
-      ;; Check proper HISTFILE setting.  We give up when not working.
-      (when (and (stringp tramp-histfile-override)
-		 (file-name-directory tramp-histfile-override))
-	(tramp-barf-unless-okay
-	 vec
-	 (format
-	  "(cd %s)"
-	  (tramp-shell-quote-argument
-	   (file-name-directory tramp-histfile-override)))
-	 "`tramp-histfile-override' uses invalid file `%s'"
-	 tramp-histfile-override)))
+    ;; It is useful to set the prompt in the following command because
+    ;; some people have a setting for $PS1 which /bin/sh doesn't know
+    ;; about and thus /bin/sh will display a strange prompt.  For
+    ;; example, if $PS1 has "${CWD}" in the value, then ksh will
+    ;; display the current working directory but /bin/sh will display
+    ;; a dollar sign.  The following command line sets $PS1 to a sane
+    ;; value, and works under Bourne-ish shells as well as csh-like
+    ;; shells.  We also unset the variable $ENV because that is read
+    ;; by some sh implementations (eg, bash when called as sh) on
+    ;; startup; this way, we avoid the startup file clobbering $PS1.
+    ;; $PROMPT_COMMAND is another way to set the prompt in /bin/bash,
+    ;; it must be discarded as well.  $HISTFILE is set according to
+    ;; `tramp-histfile-override'.  $TERM and $INSIDE_EMACS set here to
+    ;; ensure they have the correct values when the shell starts, not
+    ;; just processes run within the shell.  (Which processes include
+    ;; our initial probes to ensure the remote shell is usable.)
+    (tramp-send-command
+     vec (format
+	  (eval-when-compile
+	    (concat
+	     "exec env TERM='%s' INSIDE_EMACS='%s,tramp:%s' "
+	     "ENV=%s %s PROMPT_COMMAND='' PS1=%s PS2='' PS3='' %s %s"))
+          tramp-terminal-type
+          emacs-version tramp-version  ; INSIDE_EMACS
+          (or (getenv-internal "ENV" tramp-remote-process-environment) "")
+	  (if (stringp tramp-histfile-override)
+	      (format "HISTFILE=%s"
+		      (tramp-shell-quote-argument tramp-histfile-override))
+	    (if tramp-histfile-override
+		"HISTFILE='' HISTFILESIZE=0 HISTSIZE=0"
+	      ""))
+	  (tramp-shell-quote-argument tramp-end-of-output)
+	  shell (or (tramp-get-sh-extra-args shell) ""))
+     t)
+    ;; Check proper HISTFILE setting.  We give up when not working.
+    (when (and (stringp tramp-histfile-override)
+	       (file-name-directory tramp-histfile-override))
+      (tramp-barf-unless-okay
+       vec
+       (format
+	"(cd %s)"
+	(tramp-shell-quote-argument
+	 (file-name-directory tramp-histfile-override)))
+       "`tramp-histfile-override' uses invalid file `%s'"
+       tramp-histfile-override))
 
     (tramp-set-connection-property
      (tramp-get-connection-process vec) "remote-shell" shell)))
@@ -4187,9 +4290,16 @@ process to set up.  VEC specifies the connection."
   (let ((tramp-end-of-output tramp-initial-end-of-output)
 	(case-fold-search t))
     (tramp-open-shell vec (tramp-get-method-parameter vec 'tramp-remote-shell))
+    (tramp-message vec 5 "Setting up remote shell environment")
+
+    ;; Disable line editing.
+    (tramp-send-command vec "set +o vi +o emacs" t)
+
+    ;; Dump option settings in the traces.
+    (when (>= tramp-verbose 9)
+      (tramp-send-command vec "set -o" t))
 
     ;; Disable echo expansion.
-    (tramp-message vec 5 "Setting up remote shell environment")
     (tramp-send-command
      vec "stty -inlcr -onlcr -echo kill '^U' erase '^H'" t)
     ;; Check whether the echo has really been disabled.  Some
@@ -4259,8 +4369,6 @@ process to set up.  VEC specifies the connection."
 	(tramp-message
 	 vec 5 "Setting coding system to `%s' and `%s'" cs-decode cs-encode)))
 
-    (tramp-send-command vec "set +o vi +o emacs" t)
-
     ;; Check whether the remote host suffers from buggy
     ;; `send-process-string'.  This is known for FreeBSD (see comment
     ;; in `send_process', file process.c).  I've tested sending 624
@@ -4383,7 +4491,7 @@ and end of region, and are expected to replace the region contents
 with the encoded or decoded results, respectively.")
 
 (defconst tramp-remote-coding-commands
-  `((b64 "base64" "base64 -d -i")
+  '((b64 "base64" "base64 -d -i")
     ;; "-i" is more robust with older base64 from GNU coreutils.
     ;; However, I don't know whether all base64 versions do supports
     ;; this option.
@@ -4394,8 +4502,9 @@ with the encoded or decoded results, respectively.")
     (b64 "recode data..base64" "recode base64..data")
     (b64 tramp-perl-encode-with-module tramp-perl-decode-with-module)
     (b64 tramp-perl-encode tramp-perl-decode)
-    ;; This is painful slow, so we put it on the end.
-    (b64 tramp-awk-encode tramp-awk-decode ,tramp-awk-coding-test)
+    ;; These are painfully slow, so we put them on the end.
+    (b64 tramp-hexdump-awk-encode tramp-awk-decode)
+    (b64 tramp-od-awk-encode tramp-awk-decode)
     (uu  "uuencode xxx" "uudecode -o /dev/stdout" "test -c /dev/stdout")
     (uu  "uuencode xxx" "uudecode -o -")
     (uu  "uuencode xxx" "uudecode -p")
@@ -4421,6 +4530,8 @@ Perl or Shell implementation for this functionality.  This
 program will be transferred to the remote host, and it is
 available as shell function with the same name.  A \"%t\" format
 specifier in the variable value denotes a temporary file.
+\"%a\", \"%h\" and \"%o\" format specifiers are replaced by the
+respective `awk', `hexdump' and `od' commands.
 
 The optional TEST command can be used for further tests, whether
 ENCODING and DECODING are applicable.")
@@ -4471,11 +4582,6 @@ Goes through the list `tramp-local-coding-commands' and
 		     vec 5 "Checking remote test command `%s'" rem-test)
 		    (unless (tramp-send-command-and-check vec rem-test t)
 		      (throw 'wont-work-remote nil)))
-		  ;; Check if remote perl exists when necessary.
-		  (when (and (symbolp rem-enc)
-			     (string-match-p "perl" (symbol-name rem-enc))
-			     (not (tramp-get-remote-perl vec)))
-		    (throw 'wont-work-remote nil))
 		  ;; Check if remote encoding and decoding commands can be
 		  ;; called remotely with null input and output.  This makes
 		  ;; sure there are no syntax errors and the command is really
@@ -4485,10 +4591,36 @@ Goes through the list `tramp-local-coding-commands' and
 		  ;; redirecting "mimencode" output to /dev/null, then as root
 		  ;; it might change the permissions of /dev/null!
 		  (unless (stringp rem-enc)
-		    (let ((name (symbol-name rem-enc)))
+		    (let ((name (symbol-name rem-enc))
+			  (value (symbol-value rem-enc)))
+		      ;; Check if remote perl exists when necessary.
+		      (and (string-match-p "perl" name)
+			   (not (tramp-get-remote-perl vec))
+			   (throw 'wont-work-remote nil))
+		      ;; Check if remote awk exists when necessary.
+		      (and (string-match-p "\\(^\\|[^%]\\)%a" value)
+			   (not (tramp-get-remote-awk vec))
+			   (throw 'wont-work-remote nil))
+		      ;; Check if remote hexdump exists when necessary.
+		      (and (string-match-p "\\(^\\|[^%]\\)%h" value)
+			   (not (tramp-get-remote-hexdump vec))
+			   (throw 'wont-work-remote nil))
+		      ;; Check if remote od exists when necessary.
+		      (and (string-match-p "\\(^\\|[^%]\\)%o" value)
+			   (not (tramp-get-remote-od vec))
+			   (throw 'wont-work-remote nil))
 		      (while (string-match "-" name)
 			(setq name (replace-match "_" nil t name)))
-		      (tramp-maybe-send-script vec (symbol-value rem-enc) name)
+		      (when (string-match-p "\\(^\\|[^%]\\)%[aho]" value)
+			(setq value
+			      (format-spec
+			       value
+			       (format-spec-make
+				?a (tramp-get-remote-awk vec)
+				?h (tramp-get-remote-hexdump vec)
+				?o (tramp-get-remote-od vec)))
+			      value (replace-regexp-in-string "%" "%%" value)))
+		      (tramp-maybe-send-script vec value name)
 		      (setq rem-enc name)))
 		  (tramp-message
 		   vec 5
@@ -4503,6 +4635,15 @@ Goes through the list `tramp-local-coding-commands' and
 			  tmpfile)
 		      (while (string-match "-" name)
 			(setq name (replace-match "_" nil t name)))
+		      (when (string-match-p "\\(^\\|[^%]\\)%[aho]" value)
+			(setq value
+			      (format-spec
+			       value
+			       (format-spec-make
+				?a (tramp-get-remote-awk vec)
+				?h (tramp-get-remote-hexdump vec)
+				?o (tramp-get-remote-od vec)))
+			      value (replace-regexp-in-string "%" "%%" value)))
 		      (when (string-match-p "\\(^\\|[^%]\\)%t" value)
 			(setq tmpfile
 			      (make-temp-name
@@ -4513,7 +4654,7 @@ Goes through the list `tramp-local-coding-commands' and
 			      (format-spec
 			       value
 			       (format-spec-make
-				?t (tramp-compat-file-local-name tmpfile)))))
+				?t (tramp-file-local-name tmpfile)))))
 		      (tramp-maybe-send-script vec value name)
 		      (setq rem-dec name)))
 		  (tramp-message
@@ -4796,7 +4937,7 @@ If there is just some editing, retry it after 5 seconds."
 	 vec 5 "Cannot timeout session, trying it again in %s seconds." 5)
 	(run-at-time 5 nil 'tramp-timeout-session vec))
     (tramp-message
-     vec 3 "Timeout session %s" (tramp-make-tramp-file-name vec 'localname))
+     vec 3 "Timeout session %s" (tramp-make-tramp-file-name vec 'noloc))
     (tramp-cleanup-connection vec 'keep-debug)))
 
 (defun tramp-maybe-open-connection (vec)
@@ -5116,7 +5257,7 @@ function waits for output unless NOOUTPUT is set."
       found)))
 
 (defun tramp-send-command-and-check
-  (vec command &optional subshell dont-suppress-err)
+  (vec command &optional subshell dont-suppress-err exit-status)
   "Run COMMAND and check its exit status.
 Send `echo $?' along with the COMMAND for checking the exit status.
 If COMMAND is nil, just send `echo $?'.  Return t if the exit
@@ -5124,7 +5265,9 @@ status is 0, and nil otherwise.
 
 If the optional argument SUBSHELL is non-nil, the command is
 executed in a subshell, ie surrounded by parentheses.  If
-DONT-SUPPRESS-ERR is non-nil, stderr won't be sent to /dev/null."
+DONT-SUPPRESS-ERR is non-nil, stderr won't be sent to /dev/null.
+Optional argument EXIT-STATUS, if non-nil, triggers the return of
+the exit status."
   (tramp-send-command
    vec
    (concat (if subshell "( " "")
@@ -5138,7 +5281,9 @@ DONT-SUPPRESS-ERR is non-nil, stderr won't be sent to /dev/null."
        vec 'file-error "Couldn't find exit status of `%s'" command))
     (skip-chars-forward "^ ")
     (prog1
-	(zerop (read (current-buffer)))
+	(if exit-status
+	    (read (current-buffer))
+	  (zerop (read (current-buffer))))
       (let ((inhibit-read-only t))
 	(delete-region (match-beginning 0) (point-max))))))
 
@@ -5171,7 +5316,10 @@ raises an error."
 		    command marker (buffer-string))))))
       ;; Read the expression.
       (condition-case nil
-	  (prog1 (read (current-buffer))
+	  (prog1
+	      (let ((signal-hook-function
+		     (unless noerror signal-hook-function)))
+		(read (current-buffer)))
 	    ;; Error handling.
 	    (when (re-search-forward "\\S-" (point-at-eol) t)
 	      (error nil)))
@@ -5594,7 +5742,7 @@ This command is returned only if `delete-by-moving-to-trash' is non-nil."
 	   "%s -t %s %s"
 	   result
 	   (format-time-string "%Y%m%d%H%M.%S")
-	   (tramp-compat-file-local-name tmpfile))))
+	   (tramp-file-local-name tmpfile))))
 	(delete-file tmpfile))
       result)))
 
@@ -5769,6 +5917,47 @@ ID-FORMAT valid values are `string' and `integer'."
 	tramp-unknown-id-string)
        (t res)))))
 
+(defun tramp-get-remote-busybox (vec)
+  "Determine remote `busybox' command."
+  (with-tramp-connection-property vec "busybox"
+    (tramp-message vec 5 "Finding a suitable `busybox' command")
+    (tramp-find-executable vec "busybox" (tramp-get-remote-path vec))))
+
+(defun tramp-get-remote-awk (vec)
+  "Determine remote `awk' command."
+  (with-tramp-connection-property vec "awk"
+    (tramp-message vec 5 "Finding a suitable `awk' command")
+    (or (tramp-find-executable vec "awk" (tramp-get-remote-path vec))
+	(let* ((busybox (tramp-get-remote-busybox vec))
+	       (command (format "%s %s" busybox "awk")))
+	  (and busybox
+	       (tramp-send-command-and-check
+		vec (concat command " {} </dev/null"))
+	       command)))))
+
+(defun tramp-get-remote-hexdump (vec)
+  "Determine remote `hexdump' command."
+  (with-tramp-connection-property vec "hexdump"
+    (tramp-message vec 5 "Finding a suitable `hexdump' command")
+    (or (tramp-find-executable vec "hexdump" (tramp-get-remote-path vec))
+	(let* ((busybox (tramp-get-remote-busybox vec))
+	       (command (format "%s %s" busybox "hexdump")))
+	  (and busybox
+	       (tramp-send-command-and-check vec (concat command " </dev/null"))
+	       command)))))
+
+(defun tramp-get-remote-od (vec)
+  "Determine remote `od' command."
+  (with-tramp-connection-property vec "od"
+    (tramp-message vec 5 "Finding a suitable `od' command")
+    (or (tramp-find-executable vec "od" (tramp-get-remote-path vec))
+	(let* ((busybox (tramp-get-remote-busybox vec))
+	       (command (format "%s %s" busybox "od")))
+	  (and busybox
+	       (tramp-send-command-and-check
+		vec (concat command " -A n </dev/null"))
+	       command)))))
+
 (defun tramp-get-env-with-u-option (vec)
   "Check, whether the remote `env' command supports the -u option."
   (with-tramp-connection-property vec "env-u-option"
diff --git a/lisp/net/tramp-smb.el b/lisp/net/tramp-smb.el
index bf77ab9dee8..902fcf4b6e3 100644
--- a/lisp/net/tramp-smb.el
+++ b/lisp/net/tramp-smb.el
@@ -75,12 +75,23 @@
 
 ;;;###tramp-autoload
 (defcustom tramp-smb-conf "/dev/null"
-  "Path of the smb.conf file.
-If it is nil, no smb.conf will be added to the `tramp-smb-program'
+  "Path of the \"smb.conf\" file.
+If it is nil, no \"smb.conf\" will be added to the `tramp-smb-program'
 call, letting the SMB client use the default one."
   :group 'tramp
   :type '(choice (const nil) (file :must-match t)))
 
+;;;###tramp-autoload
+(defcustom tramp-smb-options nil
+  "List of additional options.
+They are added to the `tramp-smb-program' call via \"--option '...'\".
+
+For example, if the deprecated SMB1 protocol shall be used, add to
+this variable (\"client min protocol=NT1\") ."
+  :group 'tramp
+  :type '(repeat string)
+  :version "27.2")
+
 (defvar tramp-smb-version nil
   "Version string of the SMB client.")
 
@@ -135,6 +146,7 @@ call, letting the SMB client use the default one."
 	 "NT_STATUS_HOST_UNREACHABLE"
 	 "NT_STATUS_IMAGE_ALREADY_LOADED"
 	 "NT_STATUS_INVALID_LEVEL"
+	 "NT_STATUS_INVALID_PARAMETER"
 	 "NT_STATUS_INVALID_PARAMETER_MIX"
 	 "NT_STATUS_IO_TIMEOUT"
 	 "NT_STATUS_LOGON_FAILURE"
@@ -461,7 +473,8 @@ pass to the OPERATION."
 			       (expand-file-name
 				tramp-temp-name-prefix
 				(tramp-compat-temporary-file-directory))))
-		   (args      (list (concat "//" host "/" share) "-E")))
+		   (args      (list (concat "//" host "/" share) "-E"))
+		   (options   tramp-smb-options))
 
 	      (if (not (zerop (length user)))
 		  (setq args (append args (list "-U" user)))
@@ -471,6 +484,10 @@ pass to the OPERATION."
 	      (when port   (setq args (append args (list "-p" port))))
 	      (when tramp-smb-conf
 		(setq args (append args (list "-s" tramp-smb-conf))))
+	      (while options
+		(setq args
+		      (append args `("--option" ,(format "%s" (car options))))
+		      options (cdr options)))
 	      (setq args
 		    (if t1
 			;; Source is remote.
@@ -760,7 +777,8 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	  (let* ((share     (tramp-smb-get-share v))
 		 (localname (replace-regexp-in-string
 			     "\\\\" "/" (tramp-smb-get-localname v)))
-		 (args      (list (concat "//" host "/" share) "-E")))
+		 (args      (list (concat "//" host "/" share) "-E"))
+		 (options   tramp-smb-options))
 
 	    (if (not (zerop (length user)))
 		(setq args (append args (list "-U" user)))
@@ -770,6 +788,10 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 	    (when port   (setq args (append args (list "-p" port))))
 	    (when tramp-smb-conf
 	      (setq args (append args (list "-s" tramp-smb-conf))))
+	    (while options
+	      (setq args
+		    (append args `("--option" ,(format "%s" (car options))))
+		    options (cdr options)))
 	    (setq
 	     args
 	     (append args (list (tramp-unquote-shell-quote-argument localname)
@@ -1188,9 +1210,7 @@ component is used as the target of the symlink."
       (let ((non-essential t))
 	(when (and (tramp-tramp-file-p target)
 		   (tramp-file-name-equal-p v (tramp-dissect-file-name target)))
-	  (setq target
-		(tramp-file-name-localname
-		 (tramp-dissect-file-name (expand-file-name target))))))
+	  (setq target (tramp-file-local-name (expand-file-name target)))))
 
       ;; If TARGET is still remote, quote it.
       (if (tramp-tramp-file-p target)
@@ -1244,7 +1264,7 @@ component is used as the target of the symlink."
 	(setq infile (expand-file-name infile))
 	(if (tramp-equal-remote default-directory infile)
 	    ;; INFILE is on the same remote host.
-	    (setq input (with-parsed-tramp-file-name infile nil localname))
+	    (setq input (tramp-file-local-name infile))
 	  ;; INFILE must be copied to remote host.
 	  (setq input (tramp-make-tramp-temp-file v)
 		tmpinput (tramp-make-tramp-file-name v input))
@@ -1414,7 +1434,8 @@ component is used as the target of the symlink."
 			   "\\\\" "/" (tramp-smb-get-localname v)))
 	       (args      (list (concat "//" host "/" share) "-E" "-S"
 				(replace-regexp-in-string
-				 "\n" "," acl-string))))
+				 "\n" "," acl-string)))
+	       (options   tramp-smb-options))
 
 	  (if (not (zerop (length user)))
 	      (setq args (append args (list "-U" user)))
@@ -1424,6 +1445,10 @@ component is used as the target of the symlink."
 	  (when port   (setq args (append args (list "-p" port))))
 	  (when tramp-smb-conf
 	    (setq args (append args (list "-s" tramp-smb-conf))))
+	  (while options
+	    (setq args
+		  (append args `("--option" ,(format "%s" (car options))))
+		  options (cdr options)))
 	  (setq
 	   args
 	   (append args (list (tramp-unquote-shell-quote-argument localname)
@@ -1468,7 +1493,7 @@ component is used as the target of the symlink."
 	    (tramp-flush-connection-property v "process-name")
 	    (tramp-flush-connection-property v "process-buffer")))))))
 
-(defun tramp-smb-handle-set-file-modes (filename mode)
+(defun tramp-smb-handle-set-file-modes (filename mode &optional _flag)
   "Like `set-file-modes' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (when (tramp-smb-get-cifs-capabilities v)
@@ -1557,9 +1582,6 @@ errors for shares like \"C$/\", which are common in Microsoft Windows."
 		     (format "File %s exists; overwrite anyway? " filename)))))
       (tramp-error v 'file-already-exists filename))
 
-    ;; We must also flush the cache of the directory, because
-    ;; `file-attributes' reads the values from there.
-    (tramp-flush-file-properties v localname)
     (let ((curbuf (current-buffer))
 	  (tmpfile (tramp-compat-make-temp-file filename)))
       (when (and append (file-exists-p filename))
@@ -1579,6 +1601,10 @@ errors for shares like \"C$/\", which are common in Microsoft Windows."
 	      (tramp-error v 'file-error "Cannot write `%s'" filename))
 	  (delete-file tmpfile)))
 
+      ;; We must also flush the cache of the directory, because
+      ;; `file-attributes' reads the values from there.
+      (tramp-flush-file-properties v localname)
+
       (unless (equal curbuf (current-buffer))
 	(tramp-error
 	 v 'file-error
@@ -1949,6 +1975,7 @@ If ARGUMENT is non-nil, use it as argument for
 	       (host   (tramp-file-name-host vec))
 	       (domain (tramp-file-name-domain vec))
 	       (port   (tramp-file-name-port vec))
+	       (options tramp-smb-options)
 	       args)
 
 	  (cond
@@ -1967,6 +1994,10 @@ If ARGUMENT is non-nil, use it as argument for
 	  (when port   (setq args (append args (list "-p" port))))
 	  (when tramp-smb-conf
 	    (setq args (append args (list "-s" tramp-smb-conf))))
+	  (while options
+	    (setq args
+		  (append args `("--option" ,(format "%s" (car options))))
+		  options (cdr options)))
 	  (when argument
 	    (setq args (append args (list argument))))
 
@@ -2132,7 +2163,5 @@ Removes smb prompt.  Returns nil if an error message has appeared."
 ;;
 ;; * Try to remove the inclusion of dummy "" directory.  Seems to be at
 ;;   several places, especially in `tramp-smb-handle-insert-directory'.
-;;
-;; * Ignore case in file names.
 
 ;;; tramp-smb.el ends here
diff --git a/lisp/net/tramp-sudoedit.el b/lisp/net/tramp-sudoedit.el
index 08188cefde3..4af58618a6a 100644
--- a/lisp/net/tramp-sudoedit.el
+++ b/lisp/net/tramp-sudoedit.el
@@ -265,10 +265,8 @@ absolute file names."
 	      v 0 (format "%s %s to %s" msg-operation filename newname)
 	    (unless (tramp-sudoedit-send-command
 		     v sudoedit-operation
-		     (tramp-compat-file-name-unquote
-		      (tramp-compat-file-local-name filename))
-		     (tramp-compat-file-name-unquote
-		      (tramp-compat-file-local-name newname)))
+		     (tramp-unquote-file-local-name filename)
+		     (tramp-unquote-file-local-name newname))
 	      (tramp-error
 	       v 'file-error
 	       "Error %s `%s' `%s'" msg-operation filename newname))))
@@ -466,7 +464,7 @@ the result will be a local, non-Tramp, file name."
       (tramp-sudoedit-send-command
        v "test" "-r" (tramp-compat-file-name-unquote localname)))))
 
-(defun tramp-sudoedit-handle-set-file-modes (filename mode)
+(defun tramp-sudoedit-handle-set-file-modes (filename mode &optional _flag)
   "Like `set-file-modes' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (tramp-flush-file-properties v localname)
@@ -524,7 +522,7 @@ the result will be a local, non-Tramp, file name."
 		     (string-to-number (match-string 2)))
 		  (string-to-number (match-string 3)))))))))
 
-(defun tramp-sudoedit-handle-set-file-times (filename &optional time)
+(defun tramp-sudoedit-handle-set-file-times (filename &optional time _flag)
   "Like `set-file-times' for Tramp files."
   (with-parsed-tramp-file-name filename nil
     (tramp-flush-file-properties v localname)
@@ -615,9 +613,7 @@ component is used as the target of the symlink."
       (let ((non-essential t))
 	(when (and (tramp-tramp-file-p target)
 		   (tramp-file-name-equal-p v (tramp-dissect-file-name target)))
-	  (setq target
-		(tramp-file-name-localname
-		 (tramp-dissect-file-name (expand-file-name target))))))
+	  (setq target (tramp-file-local-name (expand-file-name target)))))
 
       ;; If TARGET is still remote, quote it.
       (if (tramp-tramp-file-p target)
@@ -715,8 +711,7 @@ ID-FORMAT valid values are `string' and `integer'."
        (format "%d:%d"
 	       (or uid (tramp-sudoedit-get-remote-uid v 'integer))
 	       (or gid (tramp-sudoedit-get-remote-gid v 'integer)))
-       (tramp-compat-file-name-unquote
-	(tramp-compat-file-local-name filename)))))
+       (tramp-unquote-file-local-name filename))))
 
 (defun tramp-sudoedit-handle-write-region
   (start end filename &optional append visit lockname mustbenew)
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 4f3249d966a..2e6fbe1c767 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -7,7 +7,7 @@
 ;; Maintainer: Michael Albinus <michael.albinus@gmx.de>
 ;; Keywords: comm, processes
 ;; Package: tramp
-;; Version: 2.4.3
+;; Version: 2.4.5-pre
 ;; Package-Requires: ((emacs "24.4"))
 ;; Package-Type: multi
 ;; URL: https://savannah.gnu.org/projects/tramp
@@ -37,7 +37,7 @@
 ;; For more detailed instructions, please see the info file.
 ;;
 ;; Notes:
-;; -----
+;; ------
 ;;
 ;; Also see the todo list at the bottom of this file.
 ;;
@@ -46,6 +46,7 @@
 ;;
 ;; There's a mailing list for this, as well.  Its name is:
 ;;            tramp-devel@gnu.org
+
 ;; You can use the Web to subscribe, under the following URL:
 ;;            https://lists.gnu.org/mailman/listinfo/tramp-devel
 ;;
@@ -1347,6 +1348,11 @@ of `process-file', `start-file-process', or `shell-command'."
            (match-string (nth 4 tramp-file-name-structure) name))
       (tramp-compat-file-local-name name)))
 
+;; The localname can be quoted with "/:".  Extract this.
+(defun tramp-unquote-file-local-name (name)
+  "Return unquoted localname of NAME."
+  (tramp-compat-file-name-unquote (tramp-file-local-name name)))
+
 (defun tramp-find-method (method user host)
   "Return the right method string to use depending on USER and HOST.
 This is METHOD, if non-nil.  Otherwise, do a lookup in
@@ -1592,7 +1598,7 @@ necessary only.  This function will be used in file name completion."
 		  tramp-prefix-ipv6-format host tramp-postfix-ipv6-format)
 	       host)
 	     tramp-postfix-host-format))
-	  (when localname localname)))
+	  localname))
 
 (defun tramp-get-buffer (vec &optional dont-create)
   "Get the connection buffer to be used for VEC.
@@ -1648,7 +1654,7 @@ version, the function does nothing."
   "Set connection-local variables in the current buffer.
 If connection-local variables are not supported by this Emacs
 version, the function does nothing."
-  (when (file-remote-p default-directory)
+  (when (tramp-tramp-file-p default-directory)
     ;; `hack-connection-local-variables-apply' exists since Emacs 26.1.
     (tramp-compat-funcall
      'hack-connection-local-variables-apply
@@ -2864,7 +2870,7 @@ User is always nil."
   (let ((default-directory (tramp-compat-temporary-file-directory)))
     (when (file-readable-p filename)
       (with-temp-buffer
-	(insert-file-contents filename)
+	(insert-file-contents-literally filename)
 	(goto-char (point-min))
         (cl-loop while (not (eobp)) collect (funcall function))))))
 
@@ -3199,7 +3205,7 @@ User is always nil."
       (copy-file filename tmpfile 'ok-if-already-exists 'keep-time)
       tmpfile)))
 
-(defun tramp-handle-file-modes (filename)
+(defun tramp-handle-file-modes (filename &optional _flag)
   "Like `file-modes' for Tramp files."
   ;; Starting with Emacs 25.1, `when-let' can be used.
   (let ((attrs (file-attributes (or (file-truename filename) filename))))
@@ -3247,7 +3253,7 @@ User is always nil."
 		  ;; lower case letters.  This avoids us to create a
 		  ;; temporary file.
 		  (while (and (string-match-p
-			       "[a-z]" (tramp-compat-file-local-name candidate))
+			       "[a-z]" (tramp-file-local-name candidate))
 			      (not (file-exists-p candidate)))
 		    (setq candidate
 			  (directory-file-name
@@ -3257,8 +3263,7 @@ User is always nil."
 		  ;; to Emacs 26+ like `file-name-case-insensitive-p',
 		  ;; so there is no compatibility problem calling it.
 		  (unless
-		      (string-match-p
-		       "[a-z]" (tramp-compat-file-local-name candidate))
+		      (string-match-p "[a-z]" (tramp-file-local-name candidate))
 		    (setq tmpfile
 			  (let ((default-directory
 				  (file-name-directory filename)))
@@ -3271,7 +3276,7 @@ User is always nil."
 		      (file-exists-p
 		       (concat
 			(file-remote-p candidate)
-			(upcase (tramp-compat-file-local-name candidate))))
+			(upcase (tramp-file-local-name candidate))))
 		    ;; Cleanup.
 		    (when tmpfile (delete-file tmpfile)))))))))))
 
@@ -3413,7 +3418,7 @@ User is always nil."
 	       (tramp-error
 		v1 'file-error
 		"Maximum number (%d) of symlinks exceeded" numchase-limit)))
-	   (tramp-compat-file-local-name (directory-file-name result)))))))))
+	   (tramp-file-local-name (directory-file-name result)))))))))
 
 (defun tramp-handle-file-writable-p (filename)
   "Like `file-writable-p' for Tramp files."
@@ -3645,10 +3650,16 @@ support symbolic links."
   (let* ((asynchronous (string-match-p "[ \t]*&[ \t]*\\'" command))
 	 (command (substring command 0 asynchronous))
 	 current-buffer-p
+	 (output-buffer-p output-buffer)
 	 (output-buffer
 	  (cond
-	   ((bufferp output-buffer) output-buffer)
-	   ((stringp output-buffer) (get-buffer-create output-buffer))
+	   ((bufferp output-buffer)
+	    (setq current-buffer-p (eq (current-buffer) output-buffer))
+	    output-buffer)
+	   ((stringp output-buffer)
+	    (setq current-buffer-p
+		  (eq (buffer-name (current-buffer)) output-buffer))
+	    (get-buffer-create output-buffer))
 	   (output-buffer
 	    (setq current-buffer-p t)
 	    (current-buffer))
@@ -3660,13 +3671,19 @@ support symbolic links."
 	  (cond
 	   ((bufferp error-buffer) error-buffer)
 	   ((stringp error-buffer) (get-buffer-create error-buffer))))
+	 (error-file
+	  (and error-buffer
+	       (with-parsed-tramp-file-name default-directory nil
+		 (tramp-make-tramp-file-name
+		  v (tramp-make-tramp-temp-file v)))))
 	 (bname (buffer-name output-buffer))
 	 (p (get-buffer-process output-buffer))
+	 (dir default-directory)
 	 buffer)
 
     ;; The following code is taken from `shell-command', slightly
     ;; adapted.  Shouldn't it be factored out?
-    (when p
+    (when (and (integerp asynchronous) p)
       (cond
        ((eq async-shell-command-buffer 'confirm-kill-process)
 	;; If will kill a process, query first.
@@ -3698,22 +3715,25 @@ support symbolic links."
 	  (rename-uniquely))
         (setq output-buffer (get-buffer-create bname)))))
 
-    (setq buffer (if (and (not asynchronous) error-buffer)
-		     (with-parsed-tramp-file-name default-directory nil
-		       (list output-buffer
-			     (tramp-make-tramp-file-name
-			      v (tramp-make-tramp-temp-file v))))
-		   output-buffer))
-
-    (if current-buffer-p
-	(progn
-	  (barf-if-buffer-read-only)
-	  (push-mark nil t))
+    (unless output-buffer-p
       (with-current-buffer output-buffer
+	(setq default-directory dir)))
+
+    (setq buffer (if error-file (list output-buffer error-file) output-buffer))
+
+    (with-current-buffer output-buffer
+      (when current-buffer-p
+	(barf-if-buffer-read-only)
+	(push-mark nil t))
+      ;; `shell-command-save-pos-or-erase' has been introduced with
+      ;; Emacs 27.1.
+      (if (fboundp 'shell-command-save-pos-or-erase)
+	  (tramp-compat-funcall
+	   'shell-command-save-pos-or-erase current-buffer-p)
 	(setq buffer-read-only nil)
 	(erase-buffer)))
 
-    (if (and (not current-buffer-p) (integerp asynchronous))
+    (if (integerp asynchronous)
 	(let ((tramp-remote-process-environment
 	       ;; `async-shell-command-width' has been introduced with
 	       ;; Emacs 27.1.
@@ -3726,42 +3746,68 @@ support symbolic links."
 	      ;; Run the process.
 	      (setq p (start-file-process-shell-command
 		       (buffer-name output-buffer) buffer command))
-	    ;; Display output.
-	    (with-current-buffer output-buffer
-	      (display-buffer output-buffer '(nil (allow-no-window . t)))
-	      (setq mode-line-process '(":%s"))
-	      (shell-mode)
-	      (set-process-sentinel p #'shell-command-sentinel)
-	      (set-process-filter p #'comint-output-filter))))
+	    ;; Insert error messages if they were separated.
+	    (when error-file
+	      (with-current-buffer error-buffer
+		(insert-file-contents-literally error-file)))
+	    (if (process-live-p p)
+	      ;; Display output.
+	      (with-current-buffer output-buffer
+		(setq mode-line-process '(":%s"))
+		(unless (eq major-mode 'shell-mode)
+		  (shell-mode))
+		(set-process-filter p #'comint-output-filter)
+		(set-process-sentinel p #'shell-command-sentinel)
+		(when error-file
+		  (add-function
+		   :after (process-sentinel p)
+		   (lambda (_proc _string)
+		     (with-current-buffer error-buffer
+		       (insert-file-contents-literally
+			error-file nil nil nil 'replace))
+		     (delete-file error-file))))
+		(display-buffer output-buffer '(nil (allow-no-window . t))))
+
+	      (when error-file
+		(delete-file error-file)))))
 
       (prog1
 	  ;; Run the process.
 	  (process-file-shell-command command nil buffer nil)
 	;; Insert error messages if they were separated.
-	(when (listp buffer)
+	(when error-file
 	  (with-current-buffer error-buffer
-	    (insert-file-contents (cadr buffer)))
-	  (delete-file (cadr buffer)))
+	    (insert-file-contents-literally error-file))
+	  (delete-file error-file))
 	(if current-buffer-p
 	    ;; This is like exchange-point-and-mark, but doesn't
 	    ;; activate the mark.  It is cleaner to avoid activation,
 	    ;; even though the command loop would deactivate the mark
 	    ;; because we inserted text.
-	    (goto-char (prog1 (mark t)
-			 (set-marker (mark-marker) (point)
-				     (current-buffer))))
+	    (progn
+	      (goto-char (prog1 (mark t)
+			   (set-marker (mark-marker) (point)
+				       (current-buffer))))
+              ;; `shell-command-set-point-after-cmd' has been
+	      ;; introduced with Emacs 27.1.
+	      (if (fboundp 'shell-command-set-point-after-cmd)
+		  (tramp-compat-funcall
+		   'shell-command-set-point-after-cmd)))
 	  ;; There's some output, display it.
 	  (when (with-current-buffer output-buffer (> (point-max) (point-min)))
 	    (display-message-or-buffer output-buffer)))))))
 
 (defun tramp-handle-start-file-process (name buffer program &rest args)
-  "Like `start-file-process' for Tramp files."
+  "Like `start-file-process' for Tramp files.
+BUFFER might be a list, in this case STDERR is separated."
   ;; `make-process' knows the `:file-handler' argument since Emacs 27.1 only.
   (tramp-file-name-handler
    'make-process
    :name name
-   :buffer buffer
+   :buffer (if (consp buffer) (car buffer) buffer)
    :command (and program (cons program args))
+   ;; `shell-command' adds an errfile to `buffer'.
+   :stderr (when (consp buffer) (cadr buffer))
    :noquery nil
    :file-handler t))
 
@@ -4044,6 +4090,8 @@ The terminal type can be configured with `tramp-terminal-type'."
 (defun tramp-action-process-alive (proc _vec)
   "Check, whether a process has finished."
   (unless (process-live-p proc)
+    ;; There might be pending output.
+    (while (tramp-accept-process-output proc 0))
     (throw 'tramp-action 'process-died)))
 
 (defun tramp-action-out-of-band (proc vec)
@@ -4362,7 +4410,7 @@ would yield t.  On the other hand, the following check results in nil:
   (tramp-equal-remote \"/sudo::/etc\" \"/su::/etc\")
 
 If both files are local, the function returns t."
-  (or (and (null (file-remote-p file1)) (null (file-remote-p file2)))
+  (or (and (null (tramp-tramp-file-p file1)) (null (tramp-tramp-file-p file2)))
       (and (tramp-tramp-file-p file1) (tramp-tramp-file-p file2)
 	   (string-equal (file-remote-p file1) (file-remote-p file2)))))
 
@@ -4632,7 +4680,7 @@ This handles also chrooted environments, which are not regarded as local."
 	   (tramp-make-tramp-file-name
 	    vec (or (tramp-get-method-parameter vec 'tramp-tmpdir) "/tmp"))))
       (or (and (file-directory-p dir) (file-writable-p dir)
-	       (tramp-compat-file-local-name dir))
+	       (tramp-file-local-name dir))
 	  (tramp-error vec 'file-error "Directory %s not accessible" dir))
       dir)))
 
@@ -4655,7 +4703,7 @@ Return the local name of the temporary file."
 	(set-file-modes result #o0700)))
 
     ;; Return the local part.
-    (with-parsed-tramp-file-name result nil localname)))
+    (tramp-file-local-name result)))
 
 (defun tramp-delete-temp-file-function ()
   "Remove temporary files related to current buffer."
@@ -4682,7 +4730,7 @@ this file, if that variable is non-nil."
 
   (let ((system-type
 	 (if (and (stringp tramp-auto-save-directory)
-		  (file-remote-p tramp-auto-save-directory))
+		  (tramp-tramp-file-p tramp-auto-save-directory))
 	     'not-windows
 	   system-type))
 	(auto-save-file-name-transforms
@@ -4824,7 +4872,12 @@ verbosity of 6."
   "Read a password from user (compat function).
 Consults the auth-source package.
 Invokes `password-read' if available, `read-passwd' else."
-  (let* ((case-fold-search t)
+  (let* (;; If `auth-sources' contains "~/.authinfo.gpg", and
+	 ;; `exec-path' contains a relative file name like ".", it
+	 ;; could happen that the "gpg" command is not found.  So we
+	 ;; adapt `default-directory'.  (Bug#39389, Bug#39489)
+	 (default-directory (tramp-compat-temporary-file-directory))
+	 (case-fold-search t)
 	 (key (tramp-make-tramp-file-name
 	       ;; In tramp-sh.el, we must use "password-vector" due to
 	       ;; multi-hop.
@@ -4976,10 +5029,12 @@ name of a process or buffer, or nil to default to the current buffer."
 	  (tramp-error proc 'error "Process %s is not active" proc)
 	(tramp-message proc 5 "Interrupt process %s with pid %s" proc pid)
 	;; This is for tramp-sh.el.  Other backends do not support this (yet).
+	;; Not all "kill" implementations support process groups by
+	;; negative pid, so we try both variants.
 	(tramp-compat-funcall
 	 'tramp-send-command
 	 (process-get proc 'vector)
-	 (format "kill -2 -%d" pid))
+	 (format "(\\kill -2 -%d || \\kill -2 %d) 2>/dev/null" pid pid))
 	;; Wait, until the process has disappeared.  If it doesn't,
 	;; fall back to the default implementation.
         (while (tramp-accept-process-output proc 0))
diff --git a/lisp/net/trampver.el b/lisp/net/trampver.el
index dacdd44102f..4aed8abd9b3 100644
--- a/lisp/net/trampver.el
+++ b/lisp/net/trampver.el
@@ -39,7 +39,7 @@
 (defvar inhibit-message)
 
 ;;;###tramp-autoload
-(defconst tramp-version "2.4.3.27.1"
+(defconst tramp-version "2.4.5-pre"
   "This version of Tramp.")
 
 ;;;###tramp-autoload
@@ -51,6 +51,7 @@
     ;; Suppress message from `emacs-repository-get-branch'.  We must
     ;; also handle out-of-tree builds.
     (let ((inhibit-message t)
+	  (debug-on-error nil)
 	  (dir (or (locate-dominating-file (locate-library "tramp") ".git")
 		   source-directory)))
       ;; `emacs-repository-get-branch' has been introduced with Emacs 27.1.
@@ -64,6 +65,7 @@
     ;; Suppress message from `emacs-repository-get-version'.  We must
     ;; also handle out-of-tree builds.
     (let ((inhibit-message t)
+	  (debug-on-error nil)
 	  (dir (or (locate-dominating-file (locate-library "tramp") ".git")
 		   source-directory)))
       (and (stringp dir) (file-directory-p dir)
@@ -73,7 +75,7 @@
 ;; Check for Emacs version.
 (let ((x   (if (not (string-lessp emacs-version "24.4"))
       "ok"
-    (format "Tramp 2.4.3.27.1 is not fit for %s"
+    (format "Tramp 2.4.5-pre is not fit for %s"
             (replace-regexp-in-string "\n" "" (emacs-version))))))
   (unless (string-equal "ok" x) (error "%s" x)))