(mm-with-part): Set the buffer to unibyte before inserting

the handle-buffer's text, so the implicit multibyte->unibyte conversion
uses string-make-unibyte rather than string-as-unibyte.

2 files changed, 16 insertions, 14 deletions

diff --git a/lisp/gnus/ChangeLog b/lisp/gnus/ChangeLog
index e1ea5e7c6c5..21d531f59f7 100644
--- a/lisp/gnus/ChangeLog
+++ b/lisp/gnus/ChangeLog
@@ -1,5 +1,9 @@
 2008-03-12  Stefan Monnier  <monnier@iro.umontreal.ca>
 
+        * mm-decode.el (mm-with-part): Set the buffer to unibyte before inserting
+        the handle-buffer's text, so the implicit multibyte->unibyte conversion
+        uses string-make-unibyte rather than string-as-unibyte.
+
         * gnus-msg.el: Use with-current-buffer.
 
         * message.el (message-ignored-resent-headers): Add "Delivered-To".
diff --git a/lisp/gnus/mm-decode.el b/lisp/gnus/mm-decode.el
index 46bf4b8d8fe..331174ef2cf 100644
--- a/lisp/gnus/mm-decode.el
+++ b/lisp/gnus/mm-decode.el
@@ -663,11 +663,11 @@ Postpone undisplaying of viewers for types in
 
 (defun mm-copy-to-buffer ()
   "Copy the contents of the current buffer to a fresh buffer."
-    (let ((obuf (current-buffer))
-          beg)
-      (goto-char (point-min))
-      (search-forward-regexp "^\n" nil t)
-      (setq beg (point))
+  (let ((obuf (current-buffer))
+        beg)
+    (goto-char (point-min))
+    (search-forward-regexp "^\n" nil t)
+    (setq beg (point))
     (with-current-buffer
        ;; Preserve the data's unibyteness (for url-insert-file-contents).
        (let ((default-enable-multibyte-characters (mm-multibyte-p)))
@@ -1127,17 +1127,15 @@ in HANDLE."
 
 (defmacro mm-with-part (handle &rest forms)
   "Run FORMS in the temp buffer containing the contents of HANDLE."
-  `(let* ((handle ,handle)
-          ;; The multibyteness of the temp buffer should be turned on
-          ;; if inserting a multibyte string.  Contrarily, the buffer's
-          ;; multibyteness should be off if inserting a unibyte string,
-          ;; especially if a string contains 8bit data.
-          (default-enable-multibyte-characters
-            (with-current-buffer (mm-handle-buffer handle)
-              (mm-multibyte-p))))
+  ;; The handle-buffer's content is a sequence of bytes, not a sequence of
+  ;; chars, so the buffer should be unibyte.  It may happen that the
+  ;; handle-buffer is multibyte for some reason, in which case now is a good
+  ;; time to adjust it, since we know at this point that it should
+  ;; be unibyte.
+  `(let* ((handle ,handle))
      (with-temp-buffer
-       (insert-buffer-substring (mm-handle-buffer handle))
        (mm-disable-multibyte)
+       (insert-buffer-substring (mm-handle-buffer handle))
        (mm-decode-content-transfer-encoding
         (mm-handle-encoding handle)
         (mm-handle-media-type handle))