Fix bug#66093 in Tramp

* lisp/net/tramp-sshfs.el (tramp-methods): Use "%a".
(tramp-sshfs-handle-process-file): Replace ?a by "-t".

* lisp/net/tramp.el (tramp-methods): Adapt docstring.  (Bug#66093)
(tramp-handle-make-process): Replace ?a by "-t" if indicated.

lisp/net/tramp-sshfs.el

@@ -60,7 +60,7 @@
 		;; These are for remote processes.
                 (tramp-login-program        "ssh")
                 (tramp-login-args           (("-q") ("-l" "%u") ("-p" "%p")
-				             ("-e" "none") ("-t" "-t")
+				             ("-e" "none") ("%a" "%a")
 					     ("%h") ("%l")))
                 (tramp-direct-async         t)
                 (tramp-remote-shell         ,tramp-default-remote-shell)
@@ -323,7 +323,7 @@ arguments to pass to the OPERATION."
 	    ?h (or (tramp-file-name-host v) "")
 	    ?u (or (tramp-file-name-user v) "")
 	    ?p (or (tramp-file-name-port v) "")
-	    ?l command))
+            ?a "-t" ?l command))
 
 	;; Synchronize stderr.
 	(when tmpstderr

lisp/net/tramp.el

@@ -252,9 +252,9 @@ pair of the form (KEY VALUE).  The following KEYs are defined:
     \"%\" followed by a letter are expanded in the arguments as
     follows:
 
-    - \"%h\" is replaced by the host name
-    - \"%u\" is replaced by the user name
-    - \"%p\" is replaced by the port number
+    - \"%h\" is replaced by the host name.
+    - \"%u\" is replaced by the user name.
+    - \"%p\" is replaced by the port number.
     - \"%%\" can be used to obtain a literal percent character.
 
     If a sub-list containing \"%h\", \"%u\" or \"%p\" is
@@ -283,6 +283,8 @@ pair of the form (KEY VALUE).  The following KEYs are defined:
     - \"%z\" is replaced by the `tramp-scp-direct-remote-copying'
       argument if it is supported.
     - \"%d\" is replaced by the device detected by `tramp-adb-get-device'.
+    - \"%a\" adds the pseudo-terminal allocation argument \"-t\" in
+       asynchronous processes, if the connection type is not `pipe'.
 
     The existence of `tramp-login-args', combined with the
     absence of `tramp-copy-args', is an indication that the
@@ -5033,6 +5035,7 @@ substitution.  SPEC-LIST is a list of char/value pairs used for
 		  (when adb-file-name-handler-p
 		    (tramp-compat-funcall
 		     'tramp-adb-get-device v)))
+                 (pta (unless (eq connection-type 'pipe) "-t"))
 		 login-args p)
 
 	    ;; Replace `login-args' place holders.  Split
@@ -5049,7 +5052,7 @@ substitution.  SPEC-LIST is a list of char/value pairs used for
 		 v 'tramp-login-args
 		 ?h (or host "") ?u (or user "") ?p (or port "")
 		 ?c (format-spec (or options "") (format-spec-make ?t tmpfile))
-		 ?d (or device "") ?l ""))))
+		 ?d (or device "") ?a (or pta "") ?l ""))))
 	     p (make-process
 		:name name :buffer buffer
 		:command (append `(,login-program) login-args command)