Fix Bug#28982

* admin/MAINTAINERS: Add test/lisp/url/url-tramp-tests.el.

* lisp/url/url-tramp.el (url-tramp-convert-url-to-tramp)
(url-tramp-convert-tramp-to-url): Adapt to recent Tramp changes.

* test/lisp/url/url-tramp-tests.el: New file.  (Bug#28982)

admin/MAINTAINERS

@@ -62,6 +62,7 @@ Michael Albinus
             lisp/url/url-tramp.el
             doc/misc/tramp*.texi
             test/lisp/net/tramp-tests.el
+            test/lisp/url/url-tramp-tests.el
 
         D-Bus
 	    src/dbusbind.c

lisp/url/url-tramp.el

@@ -37,33 +37,41 @@ They must also be covered by `url-handler-regexp'."
   :type '(repeat string))
 
 (defun url-tramp-convert-url-to-tramp (url)
-  "Convert URL to a Tramp file name."
-  (let ((obj (url-generic-parse-url (and (stringp url) url))))
-    (if (member (url-type obj) url-tramp-protocols)
-	(progn
-	  (if (url-password obj)
-	      (password-cache-add
-	       (tramp-make-tramp-file-name
-		(url-type obj) (url-user obj) (url-host obj) "")
-	       (url-password obj))
-	    (tramp-make-tramp-file-name
-	     (url-type obj) (url-user obj) (url-host obj) (url-filename obj))))
-      url)))
+  "Convert URL to a Tramp file name.
+If URL contains a password, it will be added to the `password-data' cache.
+In case URL is not convertable, nil is returned."
+  (let* ((obj (url-generic-parse-url (and (stringp url) url)))
+         (port
+          (and (natnump (url-portspec obj))
+               (number-to-string (url-portspec obj)))))
+    (when (member (url-type obj) url-tramp-protocols)
+      (when (url-password obj)
+	(password-cache-add
+	 (tramp-make-tramp-file-name
+	  (url-type obj) (url-user obj) nil
+          (url-host obj) port "")
+	 (url-password obj)))
+      (tramp-make-tramp-file-name
+       (url-type obj) (url-user obj) nil
+       (url-host obj) port (url-filename obj)))))
 
 (defun url-tramp-convert-tramp-to-url (file)
-  "Convert FILE, a Tramp file name, to a URL."
-  (let ((obj (ignore-errors (tramp-dissect-file-name file))))
-    (if (member (tramp-file-name-method obj) url-tramp-protocols)
-	(url-recreate-url
-	 (url-parse-make-urlobj
-	  (tramp-file-name-method obj)
-	  (tramp-file-name-user obj)
-	  nil ; password.
-	  (tramp-file-name-host obj)
-	  nil ; port.
-	  (tramp-file-name-localname obj)
-	  nil nil t)) ; target attributes fullness.
-      file)))
+  "Convert FILE, a Tramp file name, to a URL.
+In case FILE is not convertable, nil is returned."
+  (let* ((obj (ignore-errors (tramp-dissect-file-name file)))
+         (port
+          (and (stringp (tramp-file-name-port obj))
+               (string-to-number (tramp-file-name-port obj)))))
+    (when (member (tramp-file-name-method obj) url-tramp-protocols)
+      (url-recreate-url
+       (url-parse-make-urlobj
+	(tramp-file-name-method obj)
+	(tramp-file-name-user obj)
+	nil ; password.
+	(tramp-file-name-host obj)
+	port
+	(tramp-file-name-localname obj)
+	nil nil t))))) ; target attributes fullness.
 
 ;;;###autoload
 (defun url-tramp-file-handler (operation &rest args)

test/lisp/url/url-tramp-tests.el

@@ -0,0 +1,83 @@
+;;; url-tramp-tests.el --- Test suite for Tramp / URL conversion.
+
+;; Copyright (C) 2017 Free Software Foundation, Inc.
+
+;; Author: Michael Albinus <michael.albinus@gmx>
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'url-tramp)
+(require 'ert)
+
+(ert-deftest url-tramp-test-convert-url-to-tramp ()
+  "Test that URLs are converted into proper Tramp file names."
+  (should
+   (string-equal
+    (url-tramp-convert-url-to-tramp "ftp://ftp.is.co.za/rfc/rfc1808.txt")
+    "/ftp:ftp.is.co.za:/rfc/rfc1808.txt"))
+
+  (should
+   (string-equal
+    (url-tramp-convert-url-to-tramp "ssh://user@localhost")
+    "/ssh:user@localhost:"))
+
+  (should
+   (string-equal
+    (url-tramp-convert-url-to-tramp "telnet://remotehost:42")
+    "/telnet:remotehost#42:"))
+
+  ;; The password will be added to the cache.  The password cache key
+  ;; is the remote file name identification of the Tramp file.
+  (should
+   (string-equal
+    (url-tramp-convert-url-to-tramp "scp://user:geheim@somewhere/localfile")
+    "/scp:user@somewhere:/localfile"))
+  (let ((key
+         (file-remote-p
+          (url-tramp-convert-url-to-tramp "scp://user@somewhere/localfile"))))
+    (should (password-in-cache-p key))
+    (should (string-equal (password-read-from-cache key) "geheim"))
+    (password-cache-remove key)
+    (should-not (password-in-cache-p key)))
+
+  ;; "http" does not belong to `url-tramp-protocols'.
+  (should-not (url-tramp-convert-url-to-tramp "http://www.gnu.org")))
+
+(ert-deftest url-tramp-test-convert-tramp-to-url ()
+  "Test that Tramp file names are converted into proper URLs."
+  (should
+   (string-equal
+    (url-tramp-convert-tramp-to-url "/ftp:ftp.is.co.za:/rfc/rfc1808.txt")
+    "ftp://ftp.is.co.za/rfc/rfc1808.txt"))
+
+  (should
+   (string-equal
+    (url-tramp-convert-tramp-to-url "/ssh:user@localhost:")
+    "ssh://user@localhost"))
+
+  (should
+   (string-equal
+    (url-tramp-convert-tramp-to-url "/telnet:user@remotehost#42:")
+    "telnet://user@remotehost:42"))
+
+  ;; "sftp" does not belong to `url-tramp-protocols'.
+  (should-not (url-tramp-convert-tramp-to-url "/sftp:user@localhost:")))
+
+(provide 'url-tramp-tests)
+
+;;; url-tramp-tests.el ends here