From: Augusto Stoffel <arstoffel@gmail.com>
Date: Sun, 29 Aug 2021 18:56:11 +0000 (+0200)
Subject: Add support for OSC 7 in comint (current directory tracking)
X-Git-Tag: emacs-28.0.90~1270
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=dce5f7aed6047b56bcec83cca36ba94b23d8f558;p=emacs.git

Add support for OSC 7 in comint (current directory tracking)

* lisp/comint.el (comint-osc-directory-tracker, comint-osc-handlers):
Define and register a handler for OSC 7.
(comint-osc-process-output): Do fewer checks on
'comint-last-output-start'.
---

diff --git a/etc/NEWS b/etc/NEWS
index 3fa22fbb579..9651ce101bc 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -3034,9 +3034,10 @@ mode.  By default, these new options support 'view-mode'.
 Adding the new 'comint-osc-process-output' to
 'comint-output-filter-functions' enables the interpretation of OSC
 ("Operating System Command") escape sequences in comint buffers.  By
-default, only OSC 8, for hyperlinks, is acted upon.  Adding more
-entries to `comint-osc-handlers' allows a customized treatment of
-further escape sequences.
+default, only OSC 8, for hyperlinks, and OSC 7, for directory
+tracking, are acted upon.  Adding more entries to
+`comint-osc-handlers' allows a customized treatment of further escape
+sequences.
 
 +++
 *** 'comint-delete-output' can now save deleted text in the kill-ring.
diff --git a/lisp/comint.el b/lisp/comint.el
index b2557dd5029..9e3042f597b 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -3896,7 +3896,8 @@ REGEXP-GROUP is the regular expression group in REGEXP to use."
 ;; OSC 8, for hyperlinks, is acted upon.  Adding more entries to
 ;; `comint-osc-handlers' allows a customized treatment of further sequences.
 
-(defvar-local comint-osc-handlers '(("8" . comint-osc-hyperlink-handler))
+(defvar-local comint-osc-handlers '(("7" . comint-osc-directory-tracker)
+                                    ("8" . comint-osc-hyperlink-handler))
   "Alist of handlers for OSC escape sequences.
 See `comint-osc-process-output' for details.")
 
@@ -3918,12 +3919,8 @@ should be a function, is called with `command' and `text' as
 arguments, with point where the escape sequence was located."
   (let ((bound (process-mark (get-buffer-process (current-buffer)))))
     (save-excursion
-      (goto-char (or comint-osc--marker
-                     (and (markerp comint-last-output-start)
-			  (eq (marker-buffer comint-last-output-start)
-			      (current-buffer))
-			  comint-last-output-start)
-                     (point-min)))
+      ;; Start one char before last output to catch a possibly stray ESC
+      (goto-char (or comint-osc--marker (1- comint-last-output-start)))
       (when (eq (char-before) ?\e) (backward-char))
       (while (re-search-forward "\e]" bound t)
         (let ((pos0 (match-beginning 0))
@@ -3940,6 +3937,30 @@ arguments, with point where the escape sequence was located."
             (put-text-property pos0 bound 'invisible t)
             (setq comint-osc--marker (copy-marker pos0))))))))
 
+;; Current directory tracking (OSC 7)
+
+(declare-function url-host "url-parse.el")
+(declare-function url-type "url-parse.el")
+(declare-function url-filename "url-parse.el")
+(defun comint-osc-directory-tracker (_ text)
+  "Update `default-directory' from OSC 7 escape sequences.
+
+This function is intended to be included as an entry of
+`comint-osc-handlers'.  You should moreover arrange for your
+shell to print the appropriate escape sequence at each prompt,
+say with the following command:
+
+    printf \"\\e]7;file://%s%s\\e\\\\\" \"$HOSTNAME\" \"$PWD\"
+
+This functionality serves as an alternative to `dirtrack-mode'
+and `shell-dirtrack-mode'."
+  (let ((url (url-generic-parse-url text)))
+    (when (and (string= (url-type url) "file")
+               (or (null (url-host url))
+                   (string= (url-host url) (system-name))))
+      (ignore-errors
+        (cd-absolute (url-unhex-string (url-filename url)))))))
+
 ;; Hyperlink handling (OSC 8)
 
 (defvar comint-osc-hyperlink-map