Tramp code cleanup

* lisp/net/tramp-sh.el (tramp-methods) <telnet, nc>:
Reintroduce "%n" marker.
(tramp-maybe-open-connection): Handle it.

* lisp/net/tramp.el (tramp-prefix-regexp):
* lisp/net/tramp-smb.el (tramp-smb-options): Fix docstring.

* lisp/net/tramp*.el: Fix typos.  Remove trailing space from
`yes-or-no-p' and `y-or-n-p' prompts.

* test/lisp/net/tramp-tests.el (tramp--test-telnet-p): New defun.
(tramp-test29-start-file-process, tramp-test30-make-process)
(tramp-test35-remote-path, tramp-test44-asynchronous-requests):
Adapt tests.

1 files changed, 23 insertions, 11 deletions

diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index af4f45d6913..9f0264abc1b 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -2083,7 +2083,7 @@ Also see `ignore'."
       "/method:host:/:/path//foo"))
 
     ;; Forwhatever reasons, the following tests let Emacs crash for
-    ;; Emacs 25, occasionally. No idea what's up.
+    ;; Emacs 25, occasionally.  No idea what's up.
     (when (tramp--test-emacs26-p)
       (should
        (string-equal
@@ -4464,7 +4464,7 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
 	      (should (string-equal (format "%s\n" fnnd) (buffer-string)))
 	      (should-not (get-buffer-window (current-buffer) t))
 
-	      ;; Second run. The output must be appended.
+	      ;; Second run.  The output must be appended.
 	      (goto-char (point-max))
 	      (should (zerop (process-file "ls" nil t t fnnd)))
 	      ;; `ls' could produce colorized output.
@@ -4588,8 +4588,10 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
 		(should
 		 (string-match-p
 		  (if (memq process-connection-type '(nil pipe))
-		      "66\n6F\n6F\n0D\n0A\n"
-		    "66\n6F\n6F\n0A\n0A\n")
+		      ;; `telnet' converts \r to <CR><NUL> if `crlf'
+		      ;; flag is FALSE.  See telnet(1) man page.
+		      "66\n6F\n6F\n0D\\(\n00\\)?\n0A\n"
+		    "66\n6F\n6F\n0A\\(\n00\\)?\n0A\n")
 		  (buffer-string))))
 
 	    ;; Cleanup.
@@ -4754,8 +4756,9 @@ If UNSTABLE is non-nil, the test is tagged as `:unstable'."
 	;; Cleanup.
 	(ignore-errors (delete-process proc)))
 
-      ;; Process with stderr buffer.
-      (unless (tramp-direct-async-process-p)
+      ;; Process with stderr buffer.  `telnet' does not cooperate with
+      ;; three processes.
+      (unless (or (tramp--test-telnet-p) (tramp-direct-async-process-p))
 	(let ((stderr (generate-new-buffer "*stderr*")))
 	  (unwind-protect
 	      (with-temp-buffer
@@ -4851,8 +4854,10 @@ If UNSTABLE is non-nil, the test is tagged as `:unstable'."
 		   (string-match-p
 		    (if (memq (or connection-type process-connection-type)
 			      '(nil pipe))
-			"66\n6F\n6F\n0D\n0A\n"
-		      "66\n6F\n6F\n0A\n0A\n")
+			;; `telnet' converts \r to <CR><NUL> if `crlf'
+			;; flag is FALSE.  See telnet(1) man page.
+			"66\n6F\n6F\n0D\\(\n00\\)?\n0A\n"
+		      "66\n6F\n6F\n0A\\(\n00\\)?\n0A\n")
 		    (buffer-string))))
 
 	      ;; Cleanup.
@@ -5498,9 +5503,9 @@ Use direct async.")
           ;; Ignore trailing newline.
 	  (setq path (substring (shell-command-to-string "echo $PATH") nil -1))
 	  ;; The shell doesn't handle such long strings.
-	  (unless (<= (length path)
-		      (tramp-get-connection-property
-		       tramp-test-vec "pipe-buf" 4096))
+	  (when (<= (length path)
+		    (tramp-get-connection-property
+		     tramp-test-vec "pipe-buf" 4096))
 	    ;; The last element of `exec-path' is `exec-directory'.
             (should
 	     (string-equal
@@ -6154,6 +6159,12 @@ This requires restrictions of file name syntax."
   "Check, whether the sudoedit method is used."
   (tramp-sudoedit-file-name-p tramp-test-temporary-file-directory))
 
+(defun tramp--test-telnet-p ()
+  "Check, whether the telnet method is used.
+This does not support special file names."
+  (string-equal
+   "telnet" (file-remote-p tramp-test-temporary-file-directory 'method)))
+
 (defun tramp--test-windows-nt-p ()
   "Check, whether the locale host runs MS Windows."
   (eq system-type 'windows-nt))
@@ -6712,6 +6723,7 @@ process sentinels.  They shall not disturb each other."
 		   (tramp--test-sh-p)))
   (skip-unless (not (tramp--test-crypt-p)))
   (skip-unless (not (tramp--test-docker-p)))
+  (skip-unless (not (tramp--test-telnet-p)))
   (skip-unless (not (tramp--test-windows-nt-p)))
 
   (with-timeout