Close bug#3992.

[gnu-emacs] / lisp / jka-cmpr-hook.el

diff --git a/lisp/jka-cmpr-hook.el b/lisp/jka-cmpr-hook.el
index fab5c6ba92578c8b732e3ad4411dc63af6ed7729..da8512d7fb90dd79144074ebf163d3a46650bfe0 100644 (file)
--- a/lisp/jka-cmpr-hook.el
+++ b/lisp/jka-cmpr-hook.el
@@ -1,7 +1,7 @@
 ;;; jka-cmpr-hook.el --- preloaded code to enable jka-compr.el
 
 ;; Copyright (C) 1993, 1994, 1995, 1997, 1999, 2000, 2002, 2003,
-;;   2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+;;   2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
 
 ;; Author: jka@ece.cmu.edu (Jay K. Adams)
 ;; Maintainer: FSF
@@ -71,10 +71,11 @@ Otherwise, it is nil.")
 
 \f
 (defun jka-compr-build-file-regexp ()
+  (purecopy
   (mapconcat
    'jka-compr-info-regexp
    jka-compr-compression-info-list
-   "\\|"))
+   "\\|")))
 
 ;; Functions for accessing the return value of jka-compr-get-compression-info
 (defun jka-compr-info-regexp               (info)  (aref info 0))