Use default-value rather than default-enable-multibyte-characters.

lisp/gnus/ChangeLog

+2009-09-04  Glenn Morris  <rgm@gnu.org>
+
+	* qp.el (quoted-printable-encode-string): Use mm-enable-multibyte, or
+	mm-disable-multibyte, rather than default-enable-multibyte-characters.
+	* utf7.el (utf7-encode, utf7-decode): Use mm-with-multibyte-buffer, or
+	mm-with-unibyte-buffer, rather than default-enable-multibyte-characters.
+	* mm-util.el (mm-with-unibyte-current-buffer)
+	(mm-find-buffer-file-coding-system):
+	* yenc.el (yenc-decode-region): Use default-value rather than
+	default-enable-multibyte-characters.
+
 2009-09-03  Glenn Morris  <rgm@gnu.org>
 
 	* mm-util.el (mm-emacs-mule, mm-default-multibyte-p):

lisp/gnus/mm-util.el

@@ -1227,7 +1227,7 @@ Use multibyte mode for this."
 
 (defmacro mm-with-unibyte-current-buffer (&rest forms)
   "Evaluate FORMS with current buffer temporarily made unibyte.
-Also bind `default-enable-multibyte-characters' to nil.
+Also bind the default-value of `enable-multibyte-characters' to nil.
 Equivalent to `progn' in XEmacs
 
 NOTE: Use this macro with caution in multibyte buffers (it is not
@@ -1242,12 +1242,12 @@ Emacs 23 (unicode)."
 	 (let ((,multibyte enable-multibyte-characters)
 	       (,buffer (current-buffer)))
 	   (unwind-protect
-	       (let (default-enable-multibyte-characters)
+	       (letf (((default-value 'enable-multibyte-characters) nil))
 		 (set-buffer-multibyte nil)
 		 ,@forms)
 	     (set-buffer ,buffer)
 	     (set-buffer-multibyte ,multibyte)))
-       (let (default-enable-multibyte-characters)
+       (letf (((default-value 'enable-multibyte-characters) nil))
 	 ,@forms))))
 (put 'mm-with-unibyte-current-buffer 'lisp-indent-function 0)
 (put 'mm-with-unibyte-current-buffer 'edebug-form-spec '(body))
@@ -1590,8 +1590,8 @@ gzip, bzip2, etc. are allowed."
 			    filename))
 		    (mm-decompress-buffer filename nil t))))
       (when decomp
-	(set-buffer (let (default-enable-multibyte-characters)
-		      (generate-new-buffer " *temp*")))
+	(set-buffer (letf (((default-value 'enable-multibyte-characters) nil))
+			  (generate-new-buffer " *temp*")))
 	(insert decomp)
 	(setq filename (file-name-sans-extension filename)))
       (goto-char (point-min))

lisp/gnus/yenc.el

@@ -89,8 +89,8 @@
 	      (when (re-search-forward "^=yend.*$" end t)
 		(setq last (match-beginning 0))
 		(setq footer-alist (yenc-parse-line (match-string 0)))
-		(let (default-enable-multibyte-characters)
-		  (setq work-buffer (generate-new-buffer " *yenc-work*")))
+		(letf (((default-value 'enable-multibyte-characters) nil))
+		      (setq work-buffer (generate-new-buffer " *yenc-work*")))
 		(while (< first last)
 		  (setq char (char-after first))
 		  (cond ((or (eq char ?\r)