Better check for multi-hops when calling direct async processes

* lisp/net/tramp-sh.el (tramp-multi-hop-p, tramp-compute-multi-hops):
Move them from here ...

* lisp/net/tramp.el (tramp-multi-hop-p, tramp-compute-multi-hops): ... here.
(tramp-direct-async-process-p): Use `tramp-compute-multi-hops'.

2 files changed, 100 insertions, 101 deletions

diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index ca43475f453..fae15fe6a8e 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -4781,104 +4781,6 @@ Goes through the list `tramp-inline-compress-commands'."
 	(tramp-message
 	 vec 2 "Couldn't find an inline transfer compress command")))))
 
-;;;###tramp-autoload
-(defun tramp-multi-hop-p (vec)
-  "Whether the method of VEC is capable of multi-hops."
-  (and (tramp-sh-file-name-handler-p vec)
-       (not (tramp-get-method-parameter vec 'tramp-copy-program))))
-
-(defun tramp-compute-multi-hops (vec)
-  "Expands VEC according to `tramp-default-proxies-alist'."
-  (let ((saved-tdpa tramp-default-proxies-alist)
-	(target-alist `(,vec))
-	(hops (or (tramp-file-name-hop vec) ""))
-	(item vec)
-	choices proxy)
-
-    ;; Ad-hoc proxy definitions.
-    (dolist (proxy (reverse (split-string hops tramp-postfix-hop-regexp 'omit)))
-      (let* ((host-port (tramp-file-name-host-port item))
-	     (user-domain (tramp-file-name-user-domain item))
-	     (proxy (concat
-		     tramp-prefix-format proxy tramp-postfix-host-format))
-	     (entry
-	      (list (and (stringp host-port)
-			 (concat "^" (regexp-quote host-port) "$"))
-		    (and (stringp user-domain)
-			 (concat "^" (regexp-quote user-domain) "$"))
-		    (propertize proxy 'tramp-ad-hoc t))))
-	(tramp-message vec 5 "Add %S to `tramp-default-proxies-alist'" entry)
-	;; Add the hop.
-	(add-to-list 'tramp-default-proxies-alist entry)
-	(setq item (tramp-dissect-file-name proxy))))
-    ;; Save the new value.
-    (when (and hops tramp-save-ad-hoc-proxies)
-      (customize-save-variable
-       'tramp-default-proxies-alist tramp-default-proxies-alist))
-
-    ;; Look for proxy hosts to be passed.
-    (setq choices tramp-default-proxies-alist)
-    (while choices
-      (setq item (pop choices)
-	    proxy (eval (nth 2 item)))
-      (when (and
-	     ;; Host.
-	     (string-match-p
-	      (or (eval (nth 0 item)) "")
-	      (or (tramp-file-name-host-port (car target-alist)) ""))
-	     ;; User.
-	     (string-match-p
-	      (or (eval (nth 1 item)) "")
-	      (or (tramp-file-name-user-domain (car target-alist)) "")))
-	(if (null proxy)
-	    ;; No more hops needed.
-	    (setq choices nil)
-	  ;; Replace placeholders.
-	  (setq proxy
-		(format-spec
-		 proxy
-		 (format-spec-make
-		  ?u (or (tramp-file-name-user (car target-alist)) "")
-		  ?h (or (tramp-file-name-host (car target-alist)) ""))))
-	  (with-parsed-tramp-file-name proxy l
-	    ;; Add the hop.
-	    (push l target-alist)
-	    ;; Start next search.
-	    (setq choices tramp-default-proxies-alist)))))
-
-    ;; Foreign and out-of-band methods are not supported for multi-hops.
-    (when (cdr target-alist)
-      (setq choices target-alist)
-      (while (setq item (pop choices))
-	(unless (tramp-multi-hop-p item)
-	  (setq tramp-default-proxies-alist saved-tdpa)
-	  (tramp-user-error
-	   vec "Method `%s' is not supported for multi-hops."
-	   (tramp-file-name-method item)))))
-
-    ;; Some methods ("su", "sg", "sudo", "doas", "ksu") do not use the
-    ;; host name in their command template.  In this case, the remote
-    ;; file name must use either a local host name (first hop), or a
-    ;; host name matching the previous hop.
-    (let ((previous-host (or tramp-local-host-regexp "")))
-      (setq choices target-alist)
-      (while (setq item (pop choices))
-	(let ((host (tramp-file-name-host item)))
-	  (unless
-	      (or
-	       ;; The host name is used for the remote shell command.
-	       (member
-		'("%h") (tramp-get-method-parameter item 'tramp-login-args))
-	       ;; The host name must match previous hop.
-	       (string-match-p previous-host host))
-	    (setq tramp-default-proxies-alist saved-tdpa)
-	    (tramp-user-error
-	     vec "Host name `%s' does not match `%s'" host previous-host))
-	  (setq previous-host (concat "^" (regexp-quote host) "$")))))
-
-    ;; Result.
-    target-alist))
-
 (defun tramp-ssh-controlmaster-options (vec)
   "Return the Control* arguments of the local ssh."
   (cond
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index ab52bec39eb..83ade66ee14 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -3634,12 +3634,109 @@ User is always nil."
 	      (delete-file local-copy)))))
       t)))
 
+(defun tramp-multi-hop-p (vec)
+  "Whether the method of VEC is capable of multi-hops."
+  (and (tramp-sh-file-name-handler-p vec)
+       (not (tramp-get-method-parameter vec 'tramp-copy-program))))
+
+(defun tramp-compute-multi-hops (vec)
+  "Expands VEC according to `tramp-default-proxies-alist'."
+  (let ((saved-tdpa tramp-default-proxies-alist)
+	(target-alist `(,vec))
+	(hops (or (tramp-file-name-hop vec) ""))
+	(item vec)
+	choices proxy)
+
+    ;; Ad-hoc proxy definitions.
+    (dolist (proxy (reverse (split-string hops tramp-postfix-hop-regexp 'omit)))
+      (let* ((host-port (tramp-file-name-host-port item))
+	     (user-domain (tramp-file-name-user-domain item))
+	     (proxy (concat
+		     tramp-prefix-format proxy tramp-postfix-host-format))
+	     (entry
+	      (list (and (stringp host-port)
+			 (concat "^" (regexp-quote host-port) "$"))
+		    (and (stringp user-domain)
+			 (concat "^" (regexp-quote user-domain) "$"))
+		    (propertize proxy 'tramp-ad-hoc t))))
+	(tramp-message vec 5 "Add %S to `tramp-default-proxies-alist'" entry)
+	;; Add the hop.
+	(add-to-list 'tramp-default-proxies-alist entry)
+	(setq item (tramp-dissect-file-name proxy))))
+    ;; Save the new value.
+    (when (and hops tramp-save-ad-hoc-proxies)
+      (customize-save-variable
+       'tramp-default-proxies-alist tramp-default-proxies-alist))
+
+    ;; Look for proxy hosts to be passed.
+    (setq choices tramp-default-proxies-alist)
+    (while choices
+      (setq item (pop choices)
+	    proxy (eval (nth 2 item)))
+      (when (and
+	     ;; Host.
+	     (string-match-p
+	      (or (eval (nth 0 item)) "")
+	      (or (tramp-file-name-host-port (car target-alist)) ""))
+	     ;; User.
+	     (string-match-p
+	      (or (eval (nth 1 item)) "")
+	      (or (tramp-file-name-user-domain (car target-alist)) "")))
+	(if (null proxy)
+	    ;; No more hops needed.
+	    (setq choices nil)
+	  ;; Replace placeholders.
+	  (setq proxy
+		(format-spec
+		 proxy
+		 (format-spec-make
+		  ?u (or (tramp-file-name-user (car target-alist)) "")
+		  ?h (or (tramp-file-name-host (car target-alist)) ""))))
+	  (with-parsed-tramp-file-name proxy l
+	    ;; Add the hop.
+	    (push l target-alist)
+	    ;; Start next search.
+	    (setq choices tramp-default-proxies-alist)))))
+
+    ;; Foreign and out-of-band methods are not supported for multi-hops.
+    (when (cdr target-alist)
+      (setq choices target-alist)
+      (while (setq item (pop choices))
+	(unless (tramp-multi-hop-p item)
+	  (setq tramp-default-proxies-alist saved-tdpa)
+	  (tramp-user-error
+	   vec "Method `%s' is not supported for multi-hops."
+	   (tramp-file-name-method item)))))
+
+    ;; Some methods ("su", "sg", "sudo", "doas", "ksu") do not use the
+    ;; host name in their command template.  In this case, the remote
+    ;; file name must use either a local host name (first hop), or a
+    ;; host name matching the previous hop.
+    (let ((previous-host (or tramp-local-host-regexp "")))
+      (setq choices target-alist)
+      (while (setq item (pop choices))
+	(let ((host (tramp-file-name-host item)))
+	  (unless
+	      (or
+	       ;; The host name is used for the remote shell command.
+	       (member
+		'("%h") (tramp-get-method-parameter item 'tramp-login-args))
+	       ;; The host name must match previous hop.
+	       (string-match-p previous-host host))
+	    (setq tramp-default-proxies-alist saved-tdpa)
+	    (tramp-user-error
+	     vec "Host name `%s' does not match `%s'" host previous-host))
+	  (setq previous-host (concat "^" (regexp-quote host) "$")))))
+
+    ;; Result.
+    target-alist))
+
 (defun tramp-direct-async-process-p (&rest args)
   "Whether direct async `make-process' can be called."
   (let ((v (tramp-dissect-file-name default-directory)))
-    (and (tramp-get-connection-property v"direct-async-process" nil)
-	   (not (tramp-multi-hop-p v))
-	   (not (plist-get args :stderr)))))
+    (and (tramp-get-connection-property v "direct-async-process" nil)
+	 (= (length (tramp-compute-multi-hops v)) 1)
+	 (not (plist-get args :stderr)))))
 
 ;; We use BUFFER also as connection buffer during setup. Because of
 ;; this, its original contents must be saved, and restored once