Subject: Re: bug#20396: 24.5; incorrect subject in replies

From: Glenn Morris <[email-masked]>
Date: Mon, 27 Apr 2015 15:30:18 -0400

Nicolas Graner wrote:

> When you reply to a message whose Subject starts with "Re: ", this is
> normally stripped from the Subject before a new "Re: " is added in the
> reply. But if the Subject is RFC2047-encoded, stripping does not
> happen and you end up with "Re: Re: " in the reply.

Thanks for the report. Does this fix it?
(Apply patch, M-x emacs-lisp-byte-compile-and-load rmail.el)

--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -3830,7 +3830,8 @@ use \\[mail-yank-original] to yank the original message into it."
 ;;;	  (setq cc resent-cc)))
     ;; Add `Re: ' to subject if not there already.
     (and (stringp subject)
-	 (setq subject
+	 (setq subject (rfc2047-decode-string subject)
+	       subject
 	       (concat rmail-reply-prefix
 		       (if (let ((case-fold-search t))
 			     (string-match rmail-reply-regexp subject))