(quoted-printable-decode-region): Avoid invalid

coding-systems.

diff --git a/lisp/gnus/qp.el b/lisp/gnus/qp.el
index 0992f239a434451dd0750dcf5bc4b9da6a6e2ce5..f83fb6f31192fb82da883942fc7e3c5300d1ccda 100644 (file)
--- a/lisp/gnus/qp.el
+++ b/lisp/gnus/qp.el
@@ -37,12 +37,14 @@
 If CODING-SYSTEM is non-nil, decode bytes into characters with that
 coding-system."
   (interactive "r")
+  (unless (mm-coding-system-p coding-system) ; e.g. `ascii' from Gnus
+    (setq coding-system nil))
   (save-excursion
     (save-restriction
-      ;; RFC 2045:  An "=" followed by two hexadecimal digits, one or
-      ;; both of which are lowercase letters in "abcdef", is formally
-      ;; illegal. A robust implementation might choose to recognize
-      ;; them as the corresponding uppercase letters.
+      ;; RFC 2045:  ``An "=" followed by two hexadecimal digits, one
+      ;; or both of which are lowercase letters in "abcdef", is
+      ;; formally illegal. A robust implementation might choose to
+      ;; recognize them as the corresponding uppercase letters.''
       (let ((case-fold-search t))
        (narrow-to-region from to)
        ;; Do this in case we're called from Gnus, say, in a buffer