Some Tramp adaptions, mainly direct async processes

* doc/misc/tramp.texi (Firewalls, Remote processes)
(Frequently Asked Questions): Add @vindex.
(Predefined connection information): Precise precondition or direct
async processes.
(Remote shell setup): Ban ssh RemoteCommand option.
(Frequently Asked Questions): Adapt quoting.

* doc/misc/trampver.texi:
* lisp/net/trampver.el: Change version to "2.5.1-pre".

* lisp/net/tramp-adb.el (tramp-methods) <adb>: Add `tramp-direct-async'
parameter.
(tramp-adb-handle-make-process): Adapt docstring.

* lisp/net/tramp-sh.el (tramp-methods) <scp, scpx, rsync, ssh, sshx>:
Add `tramp-direct-async' parameter.
(tramp-sh-handle-insert-directory): Simplify merkers.
(tramp-sh-handle-make-process): Adapt docstring.

* lisp/net/tramp.el (tramp-methods): Adapt docstring.
(tramp-debug-message): Suppress lockfiles.
(tramp-test-message): New defun.
(tramp-direct-async-process-p): Check also for `tramp-direct-async'.
(tramp-handle-make-process): Do not check for `tramp-direct-async-args'.

* test/lisp/net/tramp-tests.el (all): Replace `string-match' by
`string-match-p'.
(dired-copy-dereference): Declare.
(tramp-test-temporary-file-directory):
Remove `tramp-direct-async-args` for mock method.
(tramp-test15-copy-directory, tramp-test40-special-characters)
(tramp-test40-special-characters-with-stat)
(tramp-test40-special-characters-with-perl)
(tramp-test40-special-characters-with-ls, tramp-test41-utf8)
(tramp-test41-utf8-with-stat, tramp-test41-utf8-with-perl)
(tramp-test41-utf8-with-ls): Skip for tramp-rclone.el.
(tramp--test--deftest-direct-async-process): Do not skip for mock
method.
(tramp-test32-shell-command): Adapt test for direct async processes.
(tramp-test36-vc-registered, tramp--test-hpux-p, tramp--test-ksh-p):
Use `tramp-test-vec'.

doc/misc/tramp.texi

@@ -1622,6 +1622,7 @@ support this command.
 
 @subsection Tunneling with ssh
 
+@vindex ProxyCommand@r{, ssh option}
 With @command{ssh}, you could use the @option{ProxyCommand} entry in
 @file{~/.ssh/config}:
 
@@ -2056,9 +2057,11 @@ default value is @t{"/data/local/tmp"} for the @option{adb} method,
 @item @t{"direct-async-process"}
 
 When this property is non-@code{nil}, an alternative, more performant
-implementation of @code{make-process} and
-@code{start-file-process} is applied.  @ref{Improving performance of
-asynchronous remote processes} for a discussion of constraints.
+implementation of @code{make-process} and @code{start-file-process} is
+applied.  The connection method must also be marked with a
+non-@code{nil} @code{tramp-direct-async} parameter in
+@code{tramp-methods}.  @ref{Improving performance of asynchronous
+remote processes} for a discussion of constraints.
 
 @item @t{"posix"}
 
@@ -2214,6 +2217,11 @@ overwrite this, you might apply
 
 This uses also the settings in @code{tramp-sh-extra-args}.
 
+@vindex RemoteCommand@r{, ssh option}
+@strong{Note}: If you use an @option{ssh}-based method for connection,
+do @emph{not} set the @option{RemoteCommand} option in your
+@command{ssh} configuration, for example to @command{screen}.
+
 
 @subsection Other remote shell setup hints
 @cindex remote shell setup
@@ -3304,6 +3312,8 @@ whatever reason, then replace @code{(getenv "DISPLAY")} with a
 hard-coded, fixed name.  Note that using @code{:0} for X11 display name
 here will not work as expected.
 
+@vindex ForwardX11@r{, ssh option}
+@vindex ForwardX11Trusted@r{, ssh option}
 An alternate approach is specify @option{ForwardX11 yes} or
 @option{ForwardX11Trusted yes} in @file{~/.ssh/config} on the local
 host.
@@ -3566,6 +3576,7 @@ Furthermore, this approach has the following limitations:
 It works only for connection methods defined in @file{tramp-sh.el} and
 @file{tramp-adb.el}.
 
+@vindex ControlMaster@r{, ssh option}
 @item
 It does not support interactive user authentication.  With
 @option{ssh}-based methods, this can be avoided by using a password
@@ -4269,6 +4280,7 @@ In order to disable those optimizations, set user option
 @item
 @value{tramp} does not recognize if a @command{ssh} session hangs
 
+@vindex ServerAliveInterval@r{, ssh option}
 @command{ssh} sessions on the local host hang when the network is
 down.  @value{tramp} cannot safely detect such hangs.  The network
 configuration for @command{ssh} can be configured to kill such hangs
@@ -4285,6 +4297,8 @@ Host *
 @item
 @value{tramp} does not use default @command{ssh} @option{ControlPath}
 
+@vindex ControlPath@r{, ssh option}
+@vindex ControlPersist@r{, ssh option}
 @value{tramp} overwrites @option{ControlPath} settings when initiating
 @command{ssh} sessions.  @value{tramp} does this to fend off a stall
 if a master session opened outside the Emacs session is no longer
@@ -4306,8 +4320,8 @@ which allows you to set the @option{ControlPath} provided the variable
 @end group
 @end lisp
 
-Note how "%r", "%h" and "%p" must be encoded as "%%r", "%%h" and
-"%%p".
+Note how @samp{%r}, @samp{%h} and @samp{%p} must be encoded as
+@samp{%%r}, @samp{%%h} and @samp{%%p}.
 
 @vindex tramp-use-ssh-controlmaster-options
 If the @file{~/.ssh/config} is configured appropriately for the above
@@ -4318,6 +4332,8 @@ this @code{nil} setting:
 (customize-set-variable 'tramp-use-ssh-controlmaster-options nil)
 @end lisp
 
+@vindex ProxyCommand@r{, ssh option}
+@vindex ProxyJump@r{, ssh option}
 This shall also be set to @code{nil} if you use the
 @option{ProxyCommand} or @option{ProxyJump} options in your
 @command{ssh} configuration.

doc/misc/trampver.texi

@@ -8,7 +8,7 @@
 @c In the Tramp GIT, the version numbers are auto-frobbed from
 @c tramp.el, and the bug report address is auto-frobbed from
 @c configure.ac.
-@set trampver 2.5.0
+@set trampver 2.5.1-pre
 @set trampurl https://www.gnu.org/software/tramp/
 @set tramp-bug-report-address tramp-devel@@gnu.org
 @set emacsver 25.1

lisp/net/tramp-adb.el

@@ -98,6 +98,7 @@ It is used for TCP/IP devices."
 	      `(,tramp-adb-method
                 (tramp-login-program ,tramp-adb-program)
                 (tramp-login-args    (("shell")))
+                (tramp-direct-async  t)
 	        (tramp-tmpdir        "/data/local/tmp")
                 (tramp-default-port  5555)))
 
@@ -895,8 +896,9 @@ PRESERVE-UID-GID and PRESERVE-EXTENDED-ATTRIBUTES are completely ignored."
 ;; terminated.
 (defun tramp-adb-handle-make-process (&rest args)
   "Like `make-process' for Tramp files.
-If connection property \"direct-async-process\" is non-nil, an
-alternative implementation will be used."
+If method parameter `tramp-direct-async' and connection property
+\"direct-async-process\" are non-nil, an alternative
+implementation will be used."
   (if (tramp-direct-async-process-p args)
       (apply #'tramp-handle-make-process args)
     (when args

lisp/net/tramp-sh.el

@@ -168,6 +168,7 @@ The string is used in `tramp-methods'.")
                 (tramp-login-args           (("-l" "%u") ("-p" "%p") ("%c")
 				             ("-e" "none") ("%h")))
                 (tramp-async-args           (("-q")))
+                (tramp-direct-async         t)
                 (tramp-remote-shell         ,tramp-default-remote-shell)
                 (tramp-remote-shell-login   ("-l"))
                 (tramp-remote-shell-args    ("-c"))
@@ -183,6 +184,7 @@ The string is used in `tramp-methods'.")
 				             ("-e" "none") ("-t" "-t") ("%h")
 					     ("%l")))
                 (tramp-async-args           (("-q")))
+                (tramp-direct-async         t)
                 (tramp-remote-shell         ,tramp-default-remote-shell)
                 (tramp-remote-shell-login   ("-l"))
                 (tramp-remote-shell-args    ("-c"))
@@ -197,6 +199,7 @@ The string is used in `tramp-methods'.")
                 (tramp-login-args           (("-l" "%u") ("-p" "%p") ("%c")
 				             ("-e" "none") ("%h")))
                 (tramp-async-args           (("-q")))
+                (tramp-direct-async         t)
                 (tramp-remote-shell         ,tramp-default-remote-shell)
                 (tramp-remote-shell-login   ("-l"))
                 (tramp-remote-shell-args    ("-c"))
@@ -227,6 +230,7 @@ The string is used in `tramp-methods'.")
                 (tramp-login-args           (("-l" "%u") ("-p" "%p") ("%c")
 				             ("-e" "none") ("%h")))
                 (tramp-async-args           (("-q")))
+                (tramp-direct-async         t)
                 (tramp-remote-shell         ,tramp-default-remote-shell)
                 (tramp-remote-shell-login   ("-l"))
                 (tramp-remote-shell-args    ("-c"))))
@@ -237,6 +241,7 @@ The string is used in `tramp-methods'.")
 				             ("-e" "none") ("-t" "-t") ("%h")
 					     ("%l")))
                 (tramp-async-args           (("-q")))
+                (tramp-direct-async         t)
                 (tramp-remote-shell         ,tramp-default-remote-shell)
                 (tramp-remote-shell-login   ("-l"))
                 (tramp-remote-shell-args    ("-c"))))
@@ -2668,11 +2673,9 @@ The method used must be an out-of-band method."
                        #'file-name-nondirectory (list localname))))
                    (tramp-get-remote-null-device v))))
 
-      (let ((beg-marker (point-marker))
-	    (end-marker (point-marker))
+      (let ((beg-marker (copy-marker (point) nil))
+	    (end-marker (copy-marker (point) t))
 	    (emc enable-multibyte-characters))
-	(set-marker-insertion-type beg-marker nil)
-	(set-marker-insertion-type end-marker t)
 	;; We cannot use `insert-buffer-substring' because the Tramp
 	;; buffer changes its contents before insertion due to calling
 	;; `expand-file-name' and alike.
@@ -2837,9 +2840,9 @@ the result will be a local, non-Tramp, file name."
 ;; terminated.
 (defun tramp-sh-handle-make-process (&rest args)
   "Like `make-process' for Tramp files.
-STDERR can also be a file name.  If connection property
-\"direct-async-process\" is non-nil, an alternative
-implementation will be used."
+STDERR can also be a file name.  If method parameter `tramp-direct-async'
+and connection property \"direct-async-process\" are non-nil, an
+alternative implementation will be used."
   (if (tramp-direct-async-process-p args)
       (apply #'tramp-handle-make-process args)
     (when args

lisp/net/tramp.el

@@ -259,9 +259,9 @@ pair of the form (KEY VALUE).  The following KEYs are defined:
     parameters to suppress diagnostic messages, in order not to
     tamper the process output.
 
-  * `tramp-direct-async-args'
-    An additional argument when a direct asynchronous process is
-    started.  Used so far only in the \"mock\" method of tramp-tests.el.
+  * `tramp-direct-async'
+    Whether the method supports direct asynchronous processes.
+    Until now, just \"ssh\"-based and \"adb\"-based methods do.
 
   * `tramp-copy-program'
     This specifies the name of the program to use for remotely copying
@@ -1755,7 +1755,8 @@ The outline level is equal to the verbosity of the Tramp message."
 Message is formatted with FMT-STRING as control string and the remaining
 ARGUMENTS to actually emit the message (if applicable)."
   (let ((inhibit-message t)
-	file-name-handler-alist message-log-max signal-hook-function)
+	create-lockfiles file-name-handler-alist message-log-max
+	signal-hook-function)
     (with-current-buffer (tramp-get-debug-buffer vec)
       (goto-char (point-max))
       (let ((point (point)))
@@ -1982,6 +1983,13 @@ the resulting error message."
 
 (put #'tramp-with-demoted-errors 'tramp-suppress-trace t)
 
+(defun tramp-test-message (fmt-string &rest arguments)
+  "Emit a Tramp message according `default-directory'."
+  (if (tramp-tramp-file-p default-directory)
+      (apply #'tramp-message
+	     (tramp-dissect-file-name default-directory) 0 fmt-string arguments)
+    (apply #'message fmt-string arguments)))
+
 ;; This function provides traces in case of errors not triggered by
 ;; Tramp functions.
 (defun tramp-signal-hook-function (error-symbol data)
@@ -3741,7 +3749,9 @@ User is always nil."
   (let ((v (tramp-dissect-file-name default-directory))
 	(buffer (plist-get args :buffer))
 	(stderr (plist-get args :stderr)))
-    (and ;; It has been indicated.
+    (and ;; The method supports it.
+         (tramp-get-method-parameter v 'tramp-direct-async)
+	 ;; It has been indicated.
          (tramp-get-connection-property v "direct-async-process" nil)
 	 ;; There's no multi-hop.
 	 (or (not (tramp-multi-hop-p v))
@@ -3821,8 +3831,6 @@ It does not support `:stderr'."
 		  (tramp-get-method-parameter v 'tramp-login-args))
 		 (async-args
 		  (tramp-get-method-parameter v 'tramp-async-args))
-		 (direct-async-args
-		  (tramp-get-method-parameter v 'tramp-direct-async-args))
 		 ;; We don't create the temporary file.  In fact, it
 		 ;; is just a prefix for the ControlPath option of
 		 ;; ssh; the real temporary file has another name, and
@@ -3850,7 +3858,7 @@ It does not support `:stderr'."
 		   ?h (or host "") ?u (or user "") ?p (or port "")
 		   ?c options ?l "")
 	     ;; Add arguments for asynchronous processes.
-	     login-args (append async-args direct-async-args login-args)
+	     login-args (append async-args login-args)
 	     ;; Expand format spec.
 	     login-args
 	     (tramp-compat-flatten-tree

lisp/net/trampver.el

@@ -7,7 +7,7 @@
 ;; Maintainer: Michael Albinus <michael.albinus@gmx.de>
 ;; Keywords: comm, processes
 ;; Package: tramp
-;; Version: 2.5.0
+;; Version: 2.5.1-pre
 ;; Package-Requires: ((emacs "25.1"))
 ;; Package-Type: multi
 ;; URL: https://www.gnu.org/software/tramp/
@@ -40,7 +40,7 @@
 ;; ./configure" to change them.
 
 ;;;###tramp-autoload
-(defconst tramp-version "2.5.0"
+(defconst tramp-version "2.5.1-pre"
   "This version of Tramp.")
 
 ;;;###tramp-autoload
@@ -76,7 +76,7 @@
 ;; Check for Emacs version.
 (let ((x   (if (not (string-lessp emacs-version "25.1"))
       "ok"
-    (format "Tramp 2.5.0 is not fit for %s"
+    (format "Tramp 2.5.1-pre is not fit for %s"
             (replace-regexp-in-string "\n" "" (emacs-version))))))
   (unless (string-equal "ok" x) (error "%s" x)))