Handle auto-cd in shell-mode

* lisp/shell.el (shell-has-auto-cd): New defcustom.
(shell-directory-tracker): Handle implicit "cd".

Copyright-paperwork-exempt: yes

1 files changed, 15 insertions, 2 deletions

diff --git a/lisp/shell.el b/lisp/shell.el
index 3098d3a14da..62de5be8172 100644
--- a/lisp/shell.el
+++ b/lisp/shell.el
@@ -321,6 +321,15 @@ Thus, this does not include the shell's current directory.")
 (defvar shell-dirstack-query nil
   "Command used by `shell-resync-dirs' to query the shell.")
 
+(defcustom shell-has-auto-cd nil
+  "If non-nil, `shell-mode' handles implicit \"cd\" commands.
+Implicit \"cd\" is changing the directory if the command is a directory.
+You can make this variable buffer-local to change it, per shell-mode instance.
+Useful for shells like zsh that has this feature."
+  :type 'boolean
+  :group 'shell-directories
+  :version "28.1")
+
 (defvar shell-mode-map
   (let ((map (make-sparse-keymap)))
     (define-key map "\C-c\C-f" 'shell-forward-command)
@@ -836,13 +845,15 @@ Environment variables are expanded, see function `substitute-in-file-name'."
                                str) ; skip whitespace
                               (match-end 0)))
                 (case-fold-search)
-                end cmd arg1)
+                end cmd arg1 cmd-subst-fn)
             (while (string-match shell-command-regexp str start)
               (setq end (match-end 0)
                     cmd (comint-arguments (substring str start end) 0 0)
                     arg1 (comint-arguments (substring str start end) 1 1))
               (if arg1
                   (setq arg1 (shell-unquote-argument arg1)))
+              (if shell-has-auto-cd
+                  (setq cmd-subst-fn (comint-substitute-in-file-name cmd)))
               (cond ((string-match (concat "\\`\\(" shell-popd-regexp
                                            "\\)\\($\\|[ \t]\\)")
                                    cmd)
@@ -859,7 +870,9 @@ Environment variables are expanded, see function `substitute-in-file-name'."
                           (string-match (concat "\\`\\(" shell-chdrive-regexp
                                                 "\\)\\($\\|[ \t]\\)")
                                         cmd))
-                     (shell-process-cd (comint-substitute-in-file-name cmd))))
+                     (shell-process-cd (comint-substitute-in-file-name cmd)))
+                    ((and shell-has-auto-cd (file-directory-p cmd-subst-fn))
+                     (shell-process-cd cmd-subst-fn)))
               (setq start (progn (string-match shell-command-separator-regexp
                                                str end)
                                  ;; skip again