Backport file backup FAQ item to Emacs <28

* doc/misc/efaq.texi (Not writing files to the current directory):
Backport recommendation to Emacs 27 or older.
Problem reported by David Hedlund <davidh@gnu.org>.

(cherry picked from commit 9d62dbc1f798f65d480c6b8e6255a33e124995d0)

diff --git a/doc/misc/efaq.texi b/doc/misc/efaq.texi
index 89212119f880f0698c94a48b3f8413450aa2a470..7dc8cb26409da45625cd441217b0d87646aa92f1 100644 (file)
--- a/doc/misc/efaq.texi
+++ b/doc/misc/efaq.texi
@@ -2922,8 +2922,9 @@ For instance, to write all these things to
 @file{~/.emacs.d/aux/}:
 
 @lisp
-(setq lock-file-name-transforms
-      '(("\\`/.*/\\([^/]+\\)\\'" "~/.emacs.d/aux/\\1" t)))
+(when (>= emacs-major-version 28)
+  (setq lock-file-name-transforms
+        '(("\\`/.*/\\([^/]+\\)\\'" "~/.emacs.d/aux/\\1" t))))
 (setq auto-save-file-name-transforms
       '(("\\`/.*/\\([^/]+\\)\\'" "~/.emacs.d/aux/\\1" t)))
 (setq backup-directory-alist