Output alists with dotted pair notation in .dir-locals.el

* lisp/files-x.el (add-dir-local-variables-to-string): New function.
(modify-dir-local-variable): Use it.  (Bug#32817)

1 files changed, 26 insertions, 9 deletions

diff --git a/lisp/files-x.el b/lisp/files-x.el
index 92532e85f4f..201b7a47d5d 100644
--- a/lisp/files-x.el
+++ b/lisp/files-x.el
@@ -492,15 +492,32 @@ from the MODE alist ignoring the input argument VALUE."
       ;; Insert modified alist of directory-local variables.
       (insert ";;; Directory Local Variables\n")
       (insert ";;; For more information see (info \"(emacs) Directory Variables\")\n\n")
-      (pp (sort variables
-                (lambda (a b)
-                  (cond
-                   ((null (car a)) t)
-                   ((null (car b)) nil)
-                   ((and (symbolp (car a)) (stringp (car b))) t)
-                   ((and (symbolp (car b)) (stringp (car a))) nil)
-                   (t (string< (car a) (car b))))))
-          (current-buffer)))))
+      (princ (add-dir-local-variables-to-string
+              (sort variables
+                    (lambda (a b)
+                      (cond
+                       ((null (car a)) t)
+                       ((null (car b)) nil)
+                       ((and (symbolp (car a)) (stringp (car b))) t)
+                       ((and (symbolp (car b)) (stringp (car a))) nil)
+                       (t (string< (car a) (car b)))))))
+             (current-buffer))
+      (goto-char (point-min))
+      (indent-sexp))))
+
+(defun add-dir-local-variables-to-string (variables)
+  "Output alists of VARIABLES to string in dotted pair notation syntax."
+  (format "(%s)" (mapconcat
+                  (lambda (mode-variable)
+                    (format "(%S . %s)"
+                            (car mode-variable)
+                            (format "(%s)" (mapconcat
+                                            (lambda (variable-value)
+                                              (format "(%s . %S)"
+                                                      (car variable-value)
+                                                      (cdr variable-value)))
+                                            (cdr mode-variable) "\n"))))
+                  variables "\n")))
 
 ;;;###autoload
 (defun add-dir-local-variable (mode variable value)