Fix Tramp bug#78508

* lisp/net/tramp-container.el (tramp-methods) <docker, dockercp, podman>
<podmancp, apptainer, nspawn>:
* lisp/net/tramp-sh.el (tramp-methods) <scp, scpx, rsync>
<ssh, sshx, sudo>:
* lisp/net/tramp-sshfs.el (tramp-methods) <sshfs>: Set TERM environment.
(Bug#78508)

* lisp/net/tramp-sh.el (tramp-find-executable): Handle superlong PATH.
(tramp-set-remote-path): Simplify command.
(tramp-timeout-session): Add ;;;###tramp-autoload cookie.

* lisp/net/tramp-smb.el (tramp-smb-errors): Add string.
(tramp-smb-winexe-program): Adapt docstring.
(tramp-smb-handle-copy-directory, tramp-smb-handle-file-acl)
(tramp-smb-handle-set-file-acl, tramp-smb-maybe-open-connection):
Simplify argument handling.
(tramp-smb-handle-process-file): Flush " process-exit-status" property.
(tramp-smb-call-winexe): Set $winsize.Width to 102 only.

* lisp/net/tramp.el (tramp-process-sentinel): Adapt docstring.
Set " process-exit-status" property.

* test/lisp/net/tramp-tests.el (tramp--test-enabled):
Make it more robust.
(tramp-test18-file-attributes)
(tramp-test26-interactive-file-name-completion)
(tramp-test26-file-name-completion-boundaries)
(tramp-test35-remote-path): Adapt tests.

7 files changed, 158 insertions, 88 deletions

diff --git a/lisp/net/tramp-cache.el b/lisp/net/tramp-cache.el
index cbdaa48fc0e..721b7be123f 100644
--- a/lisp/net/tramp-cache.el
+++ b/lisp/net/tramp-cache.el
@@ -713,5 +713,7 @@ for all methods.  Resulting data are derived from connection history."
 ;;; TODO:
 ;;
 ;; * Use multisession.el, starting with Emacs 29.1.
+;;
+;; Use `with-memoization', starting with Emacs 29.1.
 
 ;;; tramp-cache.el ends here
diff --git a/lisp/net/tramp-container.el b/lisp/net/tramp-container.el
index 8429208b44b..6e82bc67be1 100644
--- a/lisp/net/tramp-container.el
+++ b/lisp/net/tramp-container.el
@@ -551,6 +551,7 @@ see its function help for a description of the format."
                 (tramp-login-args (("exec")
                                    ("-it")
                                    ("-u" "%u")
+                                   ("-e" ,(format "TERM=%s" tramp-terminal-type))
                                    ("%h")
                                    ("%l")))
                 (tramp-direct-async (,tramp-default-remote-shell "-c"))
@@ -565,6 +566,7 @@ see its function help for a description of the format."
                 (tramp-login-args (("exec")
                                    ("-it")
                                    ("-u" "%u")
+                                   ("-e" ,(format "TERM=%s" tramp-terminal-type))
                                    ("%h")
                                    ("%l")))
                 (tramp-direct-async (,tramp-default-remote-shell "-c"))
@@ -583,6 +585,7 @@ see its function help for a description of the format."
                 (tramp-login-args (("exec")
                                    ("-it")
                                    ("-u" "%u")
+                                   ("-e" ,(format "TERM=%s" tramp-terminal-type))
                                    ("%h")
                                    ("%l")))
                 (tramp-direct-async (,tramp-default-remote-shell "-c"))
@@ -597,6 +600,7 @@ see its function help for a description of the format."
                 (tramp-login-args (("exec")
                                    ("-it")
                                    ("-u" "%u")
+                                   ("-e" ,(format "TERM=%s" tramp-terminal-type))
                                    ("%h")
                                    ("%l")))
                 (tramp-direct-async (,tramp-default-remote-shell "-c"))
@@ -754,6 +758,8 @@ see its function help for a description of the format."
                `(,tramp-apptainer-method
                  (tramp-login-program ,tramp-apptainer-program)
                  (tramp-login-args (("shell")
+                                    ("--env"
+                                     ,(format "TERM=%s" tramp-terminal-type))
                                     ("instance://%h")
                                     ("%h"))) ; Needed for multi-hop check.
                  (tramp-remote-shell ,tramp-default-remote-shell)
@@ -777,6 +783,8 @@ see its function help for a description of the format."
                  (tramp-login-args (("shell")
                                     ("-q")
                                     ("--uid" "%u")
+                                    ("-E"
+                                     ,(format "TERM=%s" tramp-terminal-type))
                                     ("%h")))
                  (tramp-remote-shell ,tramp-default-remote-shell)
                  (tramp-remote-shell-login ("-l"))
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index eb446f4e2cd..679d76d0f57 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -190,7 +190,10 @@ The string is used in `tramp-methods'.")
               `("scp"
                 (tramp-login-program        "ssh")
                 (tramp-login-args           (("-l" "%u") ("-p" "%p") ("%c")
-                                             ("-e" "none") ("%h")))
+                                             ("-e" "none")
+                                             ("-o" ,(format "SetEnv=\"TERM=%s\""
+                                                            tramp-terminal-type))
+                                             ("%h")))
                 (tramp-async-args           (("-q")))
                 (tramp-direct-async         ("-t" "-t"))
                 (tramp-remote-shell         ,tramp-default-remote-shell)
@@ -208,6 +211,8 @@ The string is used in `tramp-methods'.")
                 (tramp-login-args           (("-l" "%u") ("-p" "%p") ("%c")
                                              ("-e" "none") ("-t" "-t")
                                              ("-o" "RemoteCommand=\"%l\"")
+                                             ("-o" ,(format "SetEnv=\"TERM=%s\""
+                                                            tramp-terminal-type))
                                              ("%h")))
                 (tramp-async-args           (("-q")))
                 (tramp-remote-shell         ,tramp-default-remote-shell)
@@ -223,7 +228,10 @@ The string is used in `tramp-methods'.")
               `("rsync"
                 (tramp-login-program        "ssh")
                 (tramp-login-args           (("-l" "%u") ("-p" "%p") ("%c")
-                                             ("-e" "none") ("%h")))
+                                             ("-e" "none")
+                                             ("-o" ,(format "SetEnv=\"TERM=%s\""
+                                                            tramp-terminal-type))
+                                             ("%h")))
                 (tramp-async-args           (("-q")))
                 (tramp-direct-async         t)
                 (tramp-remote-shell         ,tramp-default-remote-shell)
@@ -254,7 +262,10 @@ The string is used in `tramp-methods'.")
               `("ssh"
                 (tramp-login-program        "ssh")
                 (tramp-login-args           (("-l" "%u") ("-p" "%p") ("%c")
-                                             ("-e" "none") ("%h")))
+                                             ("-e" "none")
+                                             ("-o" ,(format "SetEnv=\"TERM=%s\""
+                                                            tramp-terminal-type))
+                                             ("%h")))
                 (tramp-async-args           (("-q")))
                 (tramp-direct-async         ("-t" "-t"))
                 (tramp-remote-shell         ,tramp-default-remote-shell)
@@ -265,6 +276,8 @@ The string is used in `tramp-methods'.")
                 (tramp-login-program        "ssh")
                 (tramp-login-args           (("-l" "%u") ("-p" "%p") ("%c")
                                              ("-e" "none") ("-t" "-t")
+                                             ("-o" ,(format "SetEnv=\"TERM=%s\""
+                                                            tramp-terminal-type))
                                              ("-o" "RemoteCommand=\"%l\"")
                                              ("%h")))
                 (tramp-async-args           (("-q")))
@@ -301,6 +314,7 @@ The string is used in `tramp-methods'.")
                 ;; remote host echoes the command.
                 ;; The "-p" argument doesn't work reliably, see Bug#50594.
                 (tramp-login-args           (("SUDO_PROMPT=P\"\"a\"\"s\"\"s\"\"w\"\"o\"\"r\"\"d\"\":")
+                                             (,(format "TERM=%s" tramp-terminal-type))
                                              ("sudo") ("-u" "%u") ("-s") ("-H")
                                              ("%l")))
                 (tramp-remote-shell         ,tramp-default-remote-shell)
@@ -4123,12 +4137,33 @@ This function expects to be in the right *tramp* buffer."
         (unless (char-equal ?~ (aref d 0))
           (setq newdl (cons d newdl))))
       (setq dirlist (nreverse newdl))))
-  (when (tramp-send-command-and-check
-         vec (format "(unalias %s; %s command -v %s)"
-                     progname
-                     (if dirlist (concat "PATH=" (string-join dirlist ":")) "")
-                     progname))
-    (string-trim (tramp-get-buffer-string (tramp-get-connection-buffer vec)))))
+  (let ((command
+         (concat
+          (when dirlist (format "PATH=%s " (string-join dirlist ":")))
+          "command -v " progname))
+        (pipe-buf (tramp-get-remote-pipe-buf vec))
+        tmpfile chunk chunksize)
+    (when (if (length< command pipe-buf)
+              (tramp-send-command-and-check vec command)
+            ;; 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 "printf \"%%b\" \"$*\" %s >>%s"
+                           (tramp-shell-quote-argument chunk)
+                           (tramp-shell-quote-argument tmpfile))))
+            (tramp-send-command-and-check
+             vec (format ". %s && rm -f %s" tmpfile tmpfile)))
+
+      (string-trim
+       (tramp-get-buffer-string (tramp-get-connection-buffer vec))))))
 
 ;; On hydra.nixos.org, the $PATH environment variable is too long to
 ;; send it.  This is likely not due to PATH_MAX, but PIPE_BUF.  We
@@ -4162,12 +4197,11 @@ variable PATH."
           (setq chunksize (min (length command) (/ pipe-buf 2))
                 chunk (substring command 0 chunksize)
                 command (substring command chunksize))
-          (tramp-send-command vec (format
-                                   "printf \"%%b\" \"$*\" %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))))))
+          (tramp-send-command
+           vec (format "printf \"%%b\" \"$*\" %s >>%s"
+                       (tramp-shell-quote-argument chunk)
+                       (tramp-shell-quote-argument tmpfile))))
+        (tramp-send-command vec (format ". %s && rm -f %s" tmpfile tmpfile))))))
 
 ;; ------------------------------------------------------------
 ;; -- Communication with external shell --
@@ -5108,6 +5142,7 @@ Goes through the list `tramp-inline-compress-commands'."
 
    (t "-3")))
 
+;;;###tramp-autoload
 (defun tramp-timeout-session (vec)
   "Close the connection VEC after a session timeout.
 If there is just some editing, retry it after 5 seconds."
diff --git a/lisp/net/tramp-smb.el b/lisp/net/tramp-smb.el
index aeb7c01c03f..db961c97523 100644
--- a/lisp/net/tramp-smb.el
+++ b/lisp/net/tramp-smb.el
@@ -162,6 +162,7 @@ this variable \"client min protocol=NT1\"."
         "NT_STATUS_PASSWORD_MUST_CHANGE"
         "NT_STATUS_RESOURCE_NAME_NOT_FOUND"
         "NT_STATUS_REVISION_MISMATCH"
+        "NT_STATUS_RPC_SS_CONTEXT_MISMATCH"
         "NT_STATUS_SHARING_VIOLATION"
         "NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE"
         "NT_STATUS_UNSUCCESSFUL"
@@ -316,7 +317,7 @@ Operations not mentioned here will be handled by the default Emacs primitives.")
 ;; Options for remote processes via winexe.
 (defcustom tramp-smb-winexe-program "winexe"
   "Name of winexe client to run.
-If it isn't found in the local $PATH, the absolute path of winexe
+If it isn't found in the local $PATH, the absolute path of \"winexe\"
 shall be given.  This is needed for remote processes."
   :group 'tramp
   :version "24.3"
@@ -488,12 +489,13 @@ arguments to pass to the OPERATION."
                        (args      (list (concat "//" host "/" share) "-E"))
                        (options   tramp-smb-options))
 
-                  (if (tramp-string-empty-or-nil-p user)
-                      (setq args (append args (list "-N")))
-                    (setq args (append args (list "-U" user))))
+                  (setq args
+                        (append args
+                         (if (tramp-string-empty-or-nil-p user)
+                             (list "-N")
+                           (list "-U" (if domain (concat domain "/" user) user)))
+                         (when port (list "-p" port))))
 
-                  (when domain (setq args (append args (list "-W" domain))))
-                  (when port   (setq args (append args (list "-p" port))))
                   (when tramp-smb-conf
                     (setq args (append args (list "-s" tramp-smb-conf))))
                   (while options
@@ -779,12 +781,13 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
                  (args      (list (concat "//" host "/" share) "-E"))
                  (options   tramp-smb-options))
 
-            (if (tramp-string-empty-or-nil-p user)
-                (setq args (append args (list "-N")))
-              (setq args (append args (list "-U" user))))
+            (setq args
+                  (append args
+                   (if (tramp-string-empty-or-nil-p user)
+                       (list "-N")
+                     (list "-U" (if domain (concat domain "/" user) user)))
+                   (when port (list "-p" port))))
 
-            (when domain (setq args (append args (list "-W" domain))))
-            (when port   (setq args (append args (list "-p" port))))
             (when tramp-smb-conf
               (setq args (append args (list "-s" tramp-smb-conf))))
             (while options
@@ -1251,6 +1254,7 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
             (tramp-set-connection-property
              v " process-buffer"
              (or outbuf (generate-new-buffer tramp-temp-buffer-name)))
+            (tramp-flush-connection-property v " process-exit-status")
             (with-current-buffer (tramp-get-connection-buffer v)
               ;; Preserve buffer contents.
               (narrow-to-region (point-max) (point-max))
@@ -1366,12 +1370,13 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
                                 (string-replace "\n" "," acl-string)))
                (options   tramp-smb-options))
 
-          (if (tramp-string-empty-or-nil-p user)
-              (setq args (append args (list "-N")))
-            (setq args (append args (list "-U" user))))
+          (setq args
+                (append args
+                 (if (tramp-string-empty-or-nil-p user)
+                     (list "-N")
+                   (list "-U" (if domain (concat domain "/" user) user)))
+                 (when port (list "-p" port))))
 
-          (when domain (setq args (append args (list "-W" domain))))
-          (when port   (setq args (append args (list "-p" port))))
           (when tramp-smb-conf
             (setq args (append args (list "-s" tramp-smb-conf))))
           (while options
@@ -1906,16 +1911,19 @@ If ARGUMENT is non-nil, use it as argument for
              (share    (setq args (list (concat "//" host "/" share))))
              (t        (setq args (list "-g" "-L" host ))))
 
-            (if (tramp-string-empty-or-nil-p user)
-                (setq args (append args (list "-N")))
-              (setq args (append args (list "-U" user))))
+            (setq args
+                  (append args
+                   (if (tramp-string-empty-or-nil-p user)
+                       (list "-N")
+                     (list "-U" (if domain (concat domain "/" user) user)))
+                   (when port (list "-p" port))))
 
-            (when domain (setq args (append args (list "-W" domain))))
-            (when port   (setq args (append args (list "-p" port))))
             (when tramp-smb-conf
               (setq args (append args (list "-s" tramp-smb-conf))))
             (dolist (option options)
               (setq args (append args (list "--option" option))))
+            ;; For debugging.
+            (setq args (append args (list "-d" "1")))
             (when argument
               (setq args (append args (list argument))))
 
@@ -2026,6 +2034,8 @@ Removes smb prompt.  Returns nil if an error message has appeared."
   (when (tramp-file-name-port vec)
     (tramp-error vec 'file-error "Port not supported for remote processes"))
 
+  ;; In case of "NT_STATUS_RPC_SS_CONTEXT_MISMATCH", the remote server
+  ;; is a Samba server.  winexe cannot install the respective service there.
   (tramp-smb-maybe-open-connection
    vec
    (format
@@ -2037,12 +2047,14 @@ Removes smb prompt.  Returns nil if an error message has appeared."
   ;; Suppress "^M".  Shouldn't we specify utf8?
   (set-process-coding-system (tramp-get-connection-process vec) 'raw-text-dos)
 
-  ;; Set width to 128.  This avoids mixing prompt and long error messages.
+  ;; Set width to 128 ($bufsize.Width) or 102 ($winsize.Width),
+  ;; respectively.  $winsize.Width cannot be larger.  This avoids
+  ;; mixing prompt and long error messages.
   (tramp-smb-send-command vec "$rawui = (Get-Host).UI.RawUI")
   (tramp-smb-send-command vec "$bufsize = $rawui.BufferSize")
   (tramp-smb-send-command vec "$winsize = $rawui.WindowSize")
   (tramp-smb-send-command vec "$bufsize.Width = 128")
-  (tramp-smb-send-command vec "$winsize.Width = 128")
+  (tramp-smb-send-command vec "$winsize.Width = 102")
   (tramp-smb-send-command vec "$rawui.BufferSize = $bufsize")
   (tramp-smb-send-command vec "$rawui.WindowSize = $winsize"))
 
@@ -2069,5 +2081,7 @@ Removes smb prompt.  Returns nil if an error message has appeared."
 ;;   several places, especially in `tramp-smb-handle-insert-directory'.
 ;;
 ;; * Keep a separate connection process per share.
+;;
+;; * Keep a permanent connection process for `process-file'.
 
 ;;; tramp-smb.el ends here
diff --git a/lisp/net/tramp-sshfs.el b/lisp/net/tramp-sshfs.el
index 3176236128a..cbc083a1fe0 100644
--- a/lisp/net/tramp-sshfs.el
+++ b/lisp/net/tramp-sshfs.el
@@ -62,6 +62,8 @@
                 (tramp-login-program        "ssh")
                 (tramp-login-args           (("-q") ("-l" "%u") ("-p" "%p")
                                              ("-e" "none") ("%a" "%a")
+                                             ("-o" ,(format "SetEnv=\"TERM=%s\""
+                                                            tramp-terminal-type))
                                              ("%h") ("%l")))
                 (tramp-direct-async         t)
                 (tramp-remote-shell         ,tramp-default-remote-shell)
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 67aa2cd0fdb..24298e8e09a 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -6255,15 +6255,22 @@ the remote host use line-endings as defined in the variable
             (process-send-string p string)))))))
 
 (defun tramp-process-sentinel (proc event)
-  "Flush file caches and remove shell prompt."
+  "Flush file caches and remove shell prompt.
+Set exit status of PROC as connection property \" process-exit-status\"."
   (unless (process-live-p proc)
     (let ((vec (process-get proc 'tramp-vector))
           (buf (process-buffer proc))
           (prompt (tramp-get-connection-property proc "prompt")))
       (when vec
-        (tramp-message vec 5 "Sentinel called: `%S' `%s'" proc event)
+        (tramp-message
+         vec 5 "Sentinel called: `%S' event: `%s' status: %s"
+         proc event (process-exit-status proc))
         (tramp-flush-connection-properties proc)
-        (tramp-flush-directory-properties vec "/"))
+        (tramp-flush-directory-properties vec "/")
+        ;; Sometimes, the process has been deleted already before we
+        ;; can retrieve the exit status.
+        (tramp-set-connection-property
+         vec " process-exit-status" (process-exit-status proc)))
       (when (buffer-live-p buf)
         (with-current-buffer buf
           (when (and prompt (tramp-search-regexp (rx (literal prompt))))
diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 349abdc44c9..b60b29fc3e6 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -278,9 +278,10 @@ being the result.")
                        (| "rclone" "sshfs") ".")
                    (file-name-nondirectory file)))
             (tramp--test-message "Delete %s" file)
-            (if (file-directory-p file)
-                (delete-directory file 'recursive)
-              (delete-file file))))))
+            (ignore-errors ;; Wrong permissions?
+              (if (file-directory-p file)
+                  (delete-directory file 'recursive)
+                (delete-file file)))))))
     ;; Cleanup connection.
     (tramp-cleanup-connection tramp-test-vec nil 'keep-password))
 
@@ -3761,11 +3762,7 @@ This tests also `access-file', `file-readable-p',
            (tmp-name2 (tramp--test-make-temp-name nil quoted))
            ;; File name with "//".
            (tmp-name3
-            (format
-             "%s%s"
-             (file-remote-p tmp-name1)
-             (replace-regexp-in-string
-              "/" "//" (file-remote-p tmp-name1 'localname))))
+            (replace-regexp-in-string "/" "//" (file-local-name tmp-name1)))
            ;; `file-ownership-preserved-p' is implemented only in tramp-sh.el.
            (test-file-ownership-preserved-p (tramp--test-sh-p))
            attr)
@@ -3887,28 +3884,13 @@ This tests also `access-file', `file-readable-p',
                 ;; symlinked files to a non-existing or cyclic target.
                 (when test-file-ownership-preserved-p
                   (should (file-ownership-preserved-p tmp-name2 'group)))
-                (delete-file tmp-name2)))
+                (delete-file tmp-name2))
 
-            ;; Check, that "//" in symlinks are handled properly.
-            (with-temp-buffer
-              (let ((default-directory ert-remote-temporary-file-directory))
-                (shell-command
-                 (format
-                  "ln -s %s %s"
-                  (tramp-file-name-localname
-                   (tramp-dissect-file-name tmp-name3))
-                  (tramp-file-name-localname
-                   (tramp-dissect-file-name tmp-name2)))
-                 t)))
-            (when (file-symlink-p tmp-name2)
+              ;; Check, that "//" in symlinks are handled properly.
+              (make-symbolic-link tmp-name3 tmp-name2)
+              (should (file-symlink-p tmp-name2))
               (setq attr (file-attributes tmp-name2))
-              (should
-               (string-equal
-                (file-attribute-type attr)
-                (funcall
-                 (if (tramp--test-sshfs-p) #'file-name-nondirectory #'identity)
-                 (tramp-file-name-localname
-                  (tramp-dissect-file-name tmp-name3)))))
+              (should (string-equal (file-attribute-type attr) tmp-name3))
               (delete-file tmp-name2))
 
             (when test-file-ownership-preserved-p
@@ -5164,7 +5146,8 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
       ;; (tramp--test-message "%s" (tramp-get-buffer-string trace-buffer))
       ;; (untrace-function #'tramp-completion-file-name-handler)
       ;; (untrace-function #'completion-file-name-table)
-      (tramp-change-syntax orig-syntax))))
+      (tramp-change-syntax orig-syntax)
+      (tramp-cleanup-connection tramp-test-vec 'keep-debug 'keep-password))))
 
 (defun tramp--test-split-on-boundary (s)
   "Return completion boundaries for string S."
@@ -5177,15 +5160,12 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
   ;; boundaries are always incorrect before that.
   (skip-unless (tramp--test-emacs31-p))
 
-  (should (equal (tramp--test-split-on-boundary "/ssh:user@host:foo")
-                 '("/ssh:user@host:" . "foo")))
-  (should (equal (tramp--test-split-on-boundary "/ssh:user@host:/~/foo")
-                 '("/ssh:user@host:/~/" . "foo")))
-  (should (equal (tramp--test-split-on-boundary "/ssh:user@host:/usr//usr/foo")
-                 '("/ssh:user@host:/usr//usr/" . "foo")))
-  (should (equal (tramp--test-split-on-boundary
-                  "/ssh:user@host:/ssh:user@host://usr/foo")
-                 '("/ssh:user@host:/ssh:user@host://usr/" . "foo"))))
+  (let ((remote (file-remote-p ert-remote-temporary-file-directory)))
+    (dolist
+        (file `(,remote ,(concat remote "/~/")
+                ,(concat remote "/usr//usr/") ,(concat remote remote "//usr/")))
+      (should (equal (tramp--test-split-on-boundary (concat file "foo"))
+                     `(,file . "foo"))))))
 
 (ert-deftest tramp-test27-load ()
   "Check `load'."
@@ -6511,6 +6491,7 @@ INPUT, if non-nil, is a string sent to the process."
             (file-remote-p default-directory 'localname)))
           ;; The shell "sh" shall always exist.
           (should (executable-find "sh" 'remote))
+
           ;; Since the last element in `exec-path' is the current
           ;; directory, an executable file in that directory will be
           ;; found.
@@ -6539,19 +6520,19 @@ INPUT, if non-nil, is a string sent to the process."
   (skip-unless (tramp--test-sh-p))
   (skip-unless (not (tramp--test-crypt-p)))
 
-  (let* ((tmp-name (tramp--test-make-temp-name))
+  (let* ((tmp-name1 (tramp--test-make-temp-name))
          (default-directory ert-remote-temporary-file-directory)
          (orig-exec-path (exec-path))
          (tramp-remote-path tramp-remote-path)
          (orig-tramp-remote-path tramp-remote-path)
-         path)
+         tmp-name2 path)
     ;; The "flatpak" method modifies `tramp-remote-path'.
     (skip-unless (not (tramp-compat-connection-local-p tramp-remote-path)))
     (unwind-protect
         (progn
           ;; Non existing directories are removed.
           (setq tramp-remote-path
-                (cons (file-remote-p tmp-name 'localname) tramp-remote-path))
+                (cons (file-remote-p tmp-name1 'localname) tramp-remote-path))
           (tramp-cleanup-connection tramp-test-vec 'keep-debug 'keep-password)
           (should (equal (exec-path) orig-exec-path))
           (setq tramp-remote-path orig-tramp-remote-path)
@@ -6564,11 +6545,11 @@ INPUT, if non-nil, is a string sent to the process."
 
           ;; We make a super long `tramp-remote-path'.
           (unless (tramp--test-container-oob-p)
-            (make-directory tmp-name)
-            (should (file-directory-p tmp-name))
+            (make-directory tmp-name1)
+            (should (file-directory-p tmp-name1))
             (while (length< (string-join orig-exec-path ":") 5000)
               (let ((dir (make-temp-file
-                          (file-name-as-directory tmp-name) 'dir)))
+                          (file-name-as-directory tmp-name1) 'dir)))
                 (should (file-directory-p dir))
                 (setq tramp-remote-path
                       (append
@@ -6591,12 +6572,33 @@ INPUT, if non-nil, is a string sent to the process."
               (should
                (string-equal path (string-join (butlast orig-exec-path) ":"))))
             ;; The shell "sh" shall always exist.
-            (should (executable-find "sh" 'remote))))
+            (should (executable-find "sh" 'remote))
+
+            ;; Since the last element in `exec-path' is the current
+            ;; directory, an executable file in that directory will be
+            ;; found.
+            (setq tmp-name2
+                  (expand-file-name
+                   "foo"
+                   (concat (file-remote-p default-directory)
+                           (car (last orig-exec-path 2)))))
+            (write-region "foo" nil tmp-name2)
+            (should (file-exists-p tmp-name2))
+
+            (set-file-modes tmp-name2 #o777)
+            (should (file-executable-p tmp-name2))
+            (should
+             (string-equal
+              (executable-find (file-name-nondirectory tmp-name2) 'remote)
+              (file-remote-p tmp-name2 'localname)))
+            (should-not
+             (executable-find
+              (concat (file-name-nondirectory tmp-name2) "foo") 'remote))))
 
       ;; Cleanup.
+      (ignore-errors (delete-directory tmp-name1 'recursive))
       (tramp-cleanup-connection tramp-test-vec 'keep-debug 'keep-password)
-      (setq tramp-remote-path orig-tramp-remote-path)
-      (ignore-errors (delete-directory tmp-name 'recursive)))))
+      (setq tramp-remote-path orig-tramp-remote-path))))
 
 (tramp--test-deftest-direct-async-process tramp-test35-remote-path)