Ref: http://lists.gnu.org/archive/html/emacs-devel/2012-03/msg00005.html
+2012-03-06 Thien-Thi Nguyen <ttn@gnuvola.org>
+
+ * info.el (Info-insert-dir): Also try "dir.gz".
+
2012-03-06 Glenn Morris <rgm@gnu.org>
* files.el (dir-locals-find-file):
(progn (setq file (expand-file-name "dir.info" truename))
(file-attributes file))
(progn (setq file (expand-file-name "DIR.INFO" truename))
+ (file-attributes file))
+ (progn (setq file (expand-file-name "dir.gz" truename))
(file-attributes file)))))
(setq dirs-done
(cons truename