ansi-osc-directory-tracker respects remote files

* etc/NEWS: ansi-osc-directory-tracker supports remote directories.

* lisp/ansi-osc.el (ansi-osc-directory-tracker):
If 'default-directory' is a remote-file form, retain that form
when 'default-directory' changes are detected.

etc/NEWS

@@ -533,6 +533,12 @@ It removes all the buttons in the specified region.
 'comint-complete-input-ring' ('C-x <up>') is like 'minibuffer-complete-history'
 but completes on comint inputs.
 
+---
+*** ansi-osc-directory-tracker now respects remote files.
+Remote file forms are now retained when changes to 'default-directory'
+are detected by this filter.  For example, /ssh:hostname:/home/username
+would have been stripped to just /home/username.
+
 ** Eshell
 
 ---

lisp/ansi-osc.el

@@ -116,6 +116,8 @@ such as with the following command:
 
     printf \"\\e]7;file://%s%s\\e\\\\\" \"$HOSTNAME\" \"$PWD\"
 
+`default-directory' remote file name forms are maintained.
+
 This functionality serves as an alternative to `dirtrack-mode'
 and `shell-dirtrack-mode'."
   (let ((url (url-generic-parse-url text)))
@@ -124,7 +126,9 @@ and `shell-dirtrack-mode'."
                    ;; Use `downcase' to match `url-generic-parse-url' behavior
                    (string= (url-host url) (downcase (system-name)))))
       (ignore-errors
-        (cd-absolute (url-unhex-string (url-filename url)))))))
+        (cd-absolute
+         (concat (file-remote-p default-directory
+                                (url-unhex-string (url-filename url)))))))))
 
 ;; Hyperlink handling (OSC 8)