Enable display mode of MIME message in rmail.

2 files changed, 815 insertions, 302 deletions

diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 3f5660e82c..af09e5468a 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -2691,75 +2691,72 @@ The current mail message becomes the message displayed."
 	  (message "Showing message %d" msg))
 	(narrow-to-region beg end)
 	(goto-char beg)
-	(if (and rmail-enable-mime
-		 (re-search-forward "mime-version: 1.0" nil t))
-	    (let ((rmail-buffer mbox-buf)
-		  (rmail-view-buffer view-buf))
-	      (funcall rmail-show-mime-function))
-	(setq body-start (search-forward "\n\n" nil t))
-	(narrow-to-region beg (point))
-	(goto-char beg)
-	(save-excursion
-	  (if (re-search-forward "^X-Coding-System: *\\(.*\\)$" nil t)
-	      (setq coding-system (intern (match-string 1)))
-	    (setq coding-system (rmail-get-coding-system))))
-	(setq character-coding (mail-fetch-field "content-transfer-encoding")
-	      is-text-message (rmail-is-text-p))
-	(if character-coding
-	    (setq character-coding (downcase character-coding)))
-	(narrow-to-region beg end)
-	;; Decode the message body into an empty view buffer using a
-	;; unibyte temporary buffer where the character decoding takes
-	;; place.
-	(with-current-buffer rmail-view-buffer
-	  (erase-buffer))
-	(if (null character-coding)
-	    ;; Do it directly since that is fast.
-	    (rmail-decode-region body-start end coding-system view-buf)
-	  ;; Can this be done directly, skipping the temp buffer?
-	  (with-temp-buffer
-	    (set-buffer-multibyte nil)
-	    (insert-buffer-substring mbox-buf body-start end)
-	    (cond
-	     ((string= character-coding "quoted-printable")
-	      ;; See bug#5441.
-	      (or (mail-unquote-printable-region (point-min) (point-max)
-						 nil t 'unibyte)
-		  (message "Malformed MIME quoted-printable message")))
-	     ((and (string= character-coding "base64") is-text-message)
-	      (condition-case err
-		  (base64-decode-region (point-min) (point-max))
-		(error (message "%s" (cdr err)))))
-	     ((eq character-coding 'uuencode)
-	      (error "uuencoded messages are not supported yet"))
-	     (t))
-	    (rmail-decode-region (point-min) (point-max)
-				 coding-system view-buf))))
 	(with-current-buffer rmail-view-buffer
 	  ;; We give the view buffer a buffer-local value of
 	  ;; rmail-header-style based on the binding in effect when
 	  ;; this function is called; `rmail-toggle-headers' can
 	  ;; inspect this value to determine how to toggle.
-	  (set (make-local-variable 'rmail-header-style) header-style)
-	  ;; Unquote quoted From lines
-	  (goto-char (point-min))
-	  (while (re-search-forward "^>+From " nil t)
-	    (beginning-of-line)
-	    (delete-char 1)
-	    (forward-line))
-	  (goto-char (point-min)))
-	;; Copy the headers to the front of the message view buffer.
-	(rmail-copy-headers beg end)
-	;; Add the separator (blank line) between headers and body;
+	  (set (make-local-variable 'rmail-header-style) header-style))
+	(if (and rmail-enable-mime
+		 (re-search-forward "mime-version: 1.0" nil t))
+	    (let ((rmail-buffer mbox-buf)
+		  (rmail-view-buffer view-buf))
+	      (funcall rmail-show-mime-function))
+	  (setq body-start (search-forward "\n\n" nil t))
+	  (narrow-to-region beg (point))
+	  (goto-char beg)
+	  (save-excursion
+	    (if (re-search-forward "^X-Coding-System: *\\(.*\\)$" nil t)
+		(setq coding-system (intern (match-string 1)))
+	      (setq coding-system (rmail-get-coding-system))))
+	  (setq character-coding (mail-fetch-field "content-transfer-encoding")
+		is-text-message (rmail-is-text-p))
+	  (if character-coding
+	      (setq character-coding (downcase character-coding)))
+	  (narrow-to-region beg end)
+	  ;; Decode the message body into an empty view buffer using a
+	  ;; unibyte temporary buffer where the character decoding takes
+	  ;; place.
+	  (with-current-buffer rmail-view-buffer
+	    (erase-buffer))
+	  (if (null character-coding)
+	      ;; Do it directly since that is fast.
+	      (rmail-decode-region body-start end coding-system view-buf)
+	    ;; Can this be done directly, skipping the temp buffer?
+	    (with-temp-buffer
+	      (set-buffer-multibyte nil)
+	      (insert-buffer-substring mbox-buf body-start end)
+	      (cond
+	       ((string= character-coding "quoted-printable")
+		;; See bug#5441.
+		(or (mail-unquote-printable-region (point-min) (point-max)
+						   nil t 'unibyte)
+		    (message "Malformed MIME quoted-printable message")))
+	       ((and (string= character-coding "base64") is-text-message)
+		(condition-case err
+		    (base64-decode-region (point-min) (point-max))
+		  (error (message "%s" (cdr err)))))
+	       ((eq character-coding 'uuencode)
+		(error "uuencoded messages are not supported yet"))
+	       (t))
+	      (rmail-decode-region (point-min) (point-max)
+				   coding-system view-buf)))
+	  (with-current-buffer rmail-view-buffer
+	    ;; Prepare the separator (blank line) before the body.
+	    (goto-char (point-min))
+	    (insert "\n")
+	    ;; Unquote quoted From lines
+	    (while (re-search-forward "^>+From " nil t)
+	      (beginning-of-line)
+	      (delete-char 1)
+	      (forward-line))
+	    (goto-char (point-min)))
+	  ;; Copy the headers to the front of the message view buffer.
+	  (rmail-copy-headers beg end))
 	;; highlight the message, activate any URL like text and add
 	;; special highlighting for and quoted material.
 	(with-current-buffer rmail-view-buffer
-	  (insert "\n")
 	  (goto-char (point-min))
-	  ;; Decode the headers according to RFC2047.
-	  (save-excursion
-	    (search-forward "\n\n" nil 'move)
-	    (rfc2047-decode-region (point-min) (point)))
 	  (rmail-highlight-headers)
 					;(rmail-activate-urls)
 					;(rmail-process-quoted-material)
@@ -4290,18 +4287,28 @@ With prefix argument N moves forward N messages with these labels.
 
 ;;;***
 
-;;;### (autoloads (rmail-mime) "rmailmm" "rmailmm.el" "222ca7c1e672a08e5799e5a72fb25049")
+;;;### (autoloads (rmail-mime) "rmailmm" "rmailmm.el" "faa9e26c7781c426785e671a040128ad")
 ;;; Generated autoloads from rmailmm.el
 
 (autoload 'rmail-mime "rmailmm" "\
-Process the current Rmail message as a MIME message.
-This creates a temporary \"*RMAIL*\" buffer holding a decoded
-copy of the message.  Inline content-types are handled according to
+Toggle displaying of a MIME message.
+
+The actualy behavior depends on the value of `rmail-enable-mime'.
+
+If `rmail-enable-mime' is t (default), this command change the
+displaying of a MIME message between decoded presentation form
+and raw data.
+
+With ARG, toggle the displaying of the current MIME entity only.
+
+If `rmail-enable-mime' is nil, this creates a temporary
+\"*RMAIL*\" buffer holding a decoded copy of the message.  Inline
+content-types are handled according to
 `rmail-mime-media-type-handlers-alist'.  By default, this
 displays text and multipart messages, and offers to download
 attachments as specfied by `rmail-mime-attachment-dirs-alist'.
 
-\(fn)" t nil)
+\(fn &optional ARG)" t nil)
 
 ;;;***
 
diff --git a/lisp/mail/rmailmm.el b/lisp/mail/rmailmm.el
index 1cd765cbf9..5733945d5f 100644
--- a/lisp/mail/rmailmm.el
+++ b/lisp/mail/rmailmm.el
@@ -96,7 +96,9 @@ The first item is a regular expression matching a content-type.
 The remaining elements are handler functions to run, in order of
 decreasing preference.  These are called until one returns non-nil.
 Note that this only applies to items with an inline Content-Disposition,
-all others are handled by `rmail-mime-bulk-handler'."
+all others are handled by `rmail-mime-bulk-handler'.
+Note also that this alist is ignored when the variable
+`rmail-enable-mime' is non-nil."
   :type '(alist :key-type regexp :value-type (repeat function))
   :version "23.1"
   :group 'rmail-mime)
@@ -130,18 +132,36 @@ automatically display the image in the buffer."
 
 ;;; End of user options.
 
+;;; Global variables that always have let-binding when referred.
+
+(defvar rmail-mime-mbox-buffer nil
+  "Buffer containing the mbox data.
+The value is usually nil, and bound to a proper value while
+processing MIME.")
+
+(defvar rmail-mime-view-buffer nil
+  "Buffer showing a message.
+The value is usually nil, and bound to a proper value while
+processing MIME.")
+
+(defvar rmail-mime-coding-system nil
+  "The first coding-system used for decoding a MIME entity.
+The value is usually nil, and bound to non-nil while inserting
+MIME entities.")
+
 ;;; MIME-entity object
 
 (defun rmail-mime-entity (type disposition transfer-encoding
-			       header body children)
-  "Retrun a newly created MIME-entity object.
+			       display header tagline body children handler)
+  "Retrun a newly created MIME-entity object from arguments.
 
-A MIME-entity is a vector of 6 elements:
+A MIME-entity is a vector of 9 elements:
 
-  [ TYPE DISPOSITION TRANSFER-ENCODING HEADER BODY CHILDREN ]
+  [TYPE DISPOSITION TRANSFER-ENCODING DISPLAY HEADER TAGLINE BODY
+   CHILDREN HANDLER]
   
-TYPE and DISPOSITION correspond to MIME headers Content-Type: and
-Cotent-Disposition: respectively, and has this format:
+TYPE and DISPOSITION correspond to MIME headers Content-Type and
+Cotent-Disposition respectively, and has this format:
 
   \(VALUE (ATTRIBUTE . VALUE) (ATTRIBUTE . VALUE) ...)
 
@@ -160,31 +180,61 @@ The corresponding TYPE argument must be:
 TRANSFER-ENCODING corresponds to MIME header
 Content-Transfer-Encoding, and is a lowercased string.
 
-HEADER and BODY are a cons (BEG . END), where BEG and END specify
-the region of the corresponding part in RMAIL's data (mbox)
-buffer.  BODY may be nil.  In that case, the current buffer is
-narrowed to the body part.
-
-CHILDREN is a list of MIME-entities for a \"multipart\" entity, and
-nil for the other types."
-  (vector type disposition transfer-encoding header body children))
+DISPLAY is a vector [CURRENT NEW], where CURRENT indicates how
+the header, tagline, and body of the entity are displayed now,
+and NEW indicates how their displaying should be updated.
+Both elements are vector [HEADER-DISPLAY TAGLINE-DISPLAY BODY-DISPLAY],
+where each element is a symbol for the corresponding item that
+has these values:
+  nil: not displayed
+  t: displayed by the decoded presentation form
+  raw: displayed by the raw MIME data (for the header and body only)
+
+HEADER and BODY are vectors [BEG END DISPLAY-FLAG], where BEG and
+END specify the region of the header or body lines in RMAIL's
+data (mbox) buffer, and DISPLAY-FLAG non-nil means that the
+header or body is, by default, displayed by the decoded
+presentation form.
+
+TAGLINE is a vector [TAG BULK-DATA DISPLAY-FLAG], where TAG is a
+string indicating the depth and index number of the entity,
+BULK-DATA is a cons (SIZE . TYPE) indicating the size and type of
+an attached data, DISPLAY-FLAG non-nil means that the tagline is,
+by default, displayed.
+
+CHILDREN is a list of child MIME-entities.  A \"multipart/*\"
+entity have one or more children.  A \"message/rfc822\" entity
+has just one child.  Any other entity has no child.
+
+HANDLER is a function to insert the entity according to DISPLAY.
+It is called with one argument ENTITY."
+  (vector type disposition transfer-encoding
+	  display header tagline body children handler))
 
 ;; Accessors for a MIME-entity object.
 (defsubst rmail-mime-entity-type (entity) (aref entity 0))
 (defsubst rmail-mime-entity-disposition (entity) (aref entity 1))
 (defsubst rmail-mime-entity-transfer-encoding (entity) (aref entity 2))
-(defsubst rmail-mime-entity-header (entity) (aref entity 3))
-(defsubst rmail-mime-entity-body (entity) (aref entity 4))
-(defsubst rmail-mime-entity-children (entity) (aref entity 5))
+(defsubst rmail-mime-entity-display (entity) (aref entity 3))
+(defsubst rmail-mime-entity-header (entity) (aref entity 4))
+(defsubst rmail-mime-entity-tagline (entity) (aref entity 5))
+(defsubst rmail-mime-entity-body (entity) (aref entity 6))
+(defsubst rmail-mime-entity-children (entity) (aref entity 7))
+(defsubst rmail-mime-entity-handler (entity) (aref entity 8))
+
+(defsubst rmail-mime-message-p ()
+  "Non-nil if and only if the current message is a MIME."
+  (or (get-text-property (point) 'rmail-mime-entity)
+      (get-text-property (point-min) 'rmail-mime-entity)))
 
 ;;; Buttons
 
 (defun rmail-mime-save (button)
   "Save the attachment using info in the BUTTON."
-  (let* ((filename (button-get button 'filename))
+  (let* ((rmail-mime-mbox-buffer rmail-view-buffer)
+	 (filename (button-get button 'filename))
 	 (directory (button-get button 'directory))
 	 (data (button-get button 'data))
-	 (mbox-buf rmail-view-buffer)
 	 (ofilename filename))
     (setq filename (expand-file-name
 		    (read-file-name (format "Save as (default: %s): " filename)
@@ -209,7 +259,8 @@ nil for the other types."
 	;; DATA is a MIME-entity object.
 	(let ((transfer-encoding (rmail-mime-entity-transfer-encoding data))
 	      (body (rmail-mime-entity-body data)))
-	  (insert-buffer-substring mbox-buf (car body) (cdr body))
+	  (insert-buffer-substring rmail-mime-mbox-buffer
+				   (aref body 0) (aref body 1))
 	  (cond ((string= transfer-encoding "base64")
 		 (ignore-errors (base64-decode-region (point-min) (point-max))))
 		((string= transfer-encoding "quoted-printable")
@@ -218,34 +269,293 @@ nil for the other types."
 
 (define-button-type 'rmail-mime-save 'action 'rmail-mime-save)
 
+(defun rmail-mime-entity-segment (pos &optional entity)
+  "Return a vector describing the displayed region of a MIME-entity at POS.
+Optional 2nd argument ENTITY is the MIME-entity at POS.
+The value is a vector [ INDEX HEADER TAGLINE BODY END], where
+  HEADER: the position of the beginning of a header
+  TAGLINE: the position of the beginning of a tagline
+  BODY: the position of the beginning of a body
+  END: the position of the end of the entity.
+  INDEX: index into the returned vector indicating where POS is."
+  (save-excursion
+    (or entity
+	(setq entity (get-text-property pos 'rmail-mime-entity)))
+    (if (not entity)
+	(vector 1 (point) (point) (point) (point))
+      (let ((current (aref (rmail-mime-entity-display entity) 0))
+	    (beg (if (and (> pos (point-min))
+			  (eq (get-text-property (1- pos) 'rmail-mime-entity)
+			      entity))
+		     (previous-single-property-change pos 'rmail-mime-entity
+						      nil (point-min))
+		   pos))
+	    (index 1)
+	    tagline-beg body-beg end)
+	(goto-char beg)
+	(if (aref current 0)
+	    (search-forward "\n\n" nil t))
+	(setq tagline-beg (point))
+	(if (>= pos tagline-beg)
+	    (setq index 2))
+	(if (aref current 1)
+	    (forward-line 1))
+	(setq body-beg (point))
+	(if (>= pos body-beg)
+	    (setq index 3))
+	(if (aref current 2)
+	    (let ((tag (aref (rmail-mime-entity-tagline entity) 0))
+		  tag2)
+	      (setq end (next-single-property-change beg 'rmail-mime-entity
+						     nil (point-max)))
+	      (while (and (< end (point-max))
+			  (setq entity (get-text-property end 'rmail-mime-entity)
+				tag2 (aref (rmail-mime-entity-tagline entity) 0))
+			  (and (> (length tag2) 0)
+			       (eq (string-match tag tag2) 0)))
+		(setq end (next-single-property-change end 'rmail-mime-entity
+						       nil (point-max)))))
+	  (setq end body-beg))
+	(vector index beg tagline-beg body-beg end)))))
+
+(defun rmail-mime-next-item ()
+  "Move point to the next displayed item of the current MIME entity.
+A MIME entity has three items; header, tagline, and body. 
+If we are in the last item of the entity, move point to the first
+item of the next entity.  If we reach the end of buffer, move
+point to the first item of the first entity (i.e. the beginning
+of buffer)."
+  (interactive)
+  (if (rmail-mime-message-p)
+      (let* ((segment (rmail-mime-entity-segment (point)))
+	     (next-pos (aref segment (1+ (aref segment 0))))
+	     (button (next-button (point))))
+	(goto-char (if (and button (< (button-start button) next-pos))
+		       (button-start button)
+		     next-pos))
+	(if (eobp)
+	    (goto-char (point-min))))))
+
+(defun rmail-mime-previous-item ()
+  "Move point to the previous displayed item of the current MIME message.
+A MIME entity has three items; header, tagline, and body.
+If we are at the beginning of the first item of the entity, move
+point to the last item of the previous entity.  If we reach the
+beginning of buffer, move point to the last item of the last
+entity."
+  (interactive)
+  (when (rmail-mime-message-p)
+    (if (bobp)
+	(goto-char (point-max)))
+    (let* ((segment (rmail-mime-entity-segment (1- (point))))
+	   (prev-pos (aref segment (aref segment 0)))
+	   (button (previous-button (point))))
+      (goto-char (if (and button (> (button-start button) prev-pos))
+		     (button-start button)
+		   prev-pos)))))
+
+(defun rmail-mime-shown-mode (entity)
+  "Make MIME-entity ENTITY displayed by the default way."
+  (let ((new (aref (rmail-mime-entity-display entity) 1)))
+    (aset new 0 (aref (rmail-mime-entity-header entity) 2))
+    (aset new 1 (aref (rmail-mime-entity-tagline entity) 2))
+    (aset new 2 (aref (rmail-mime-entity-body entity) 2))))
+  
+(defun rmail-mime-hidden-mode (entity top)
+  "Make MIME-entity ENTITY displayed in the hidden mode.
+If TOP is non-nil, display ENTITY only by the tagline.
+Otherwise, don't display ENTITY."
+  (if top
+      (let ((new (aref (rmail-mime-entity-display entity) 1)))
+	(aset new 0 nil)
+	(aset new 1 top)
+	(aset new 2 nil)
+	(aset (rmail-mime-entity-body entity) 2 nil))
+    (let ((current (aref (rmail-mime-entity-display entity) 0)))
+      (aset current 0 nil)
+      (aset current 1 nil)
+      (aset current 2 nil)))
+  (dolist (child (rmail-mime-entity-children entity))
+    (rmail-mime-hidden-mode child nil)))
+
+(defun rmail-mime-raw-mode (entity)
+  "Make MIME-entity ENTITY displayed in the raw mode."
+  (let ((new (aref (rmail-mime-entity-display entity) 1)))
+    (aset new 0 'raw)
+    (aset new 1 nil)
+    (aset new 2 'raw)
+    (dolist (child (rmail-mime-entity-children entity))
+      (rmail-mime-hidden-mode child nil))))
+
+(defun rmail-mime-toggle-raw (entity)
+  "Toggle on and off the raw display mode of MIME-entity ENTITY."
+  (let* ((pos (if (eobp) (1- (point-max)) (point)))
+	 (entity (get-text-property pos 'rmail-mime-entity))
+	 (current (aref (rmail-mime-entity-display entity) 0))
+	 (segment (rmail-mime-entity-segment pos entity)))
+    (if (not (eq (aref current 0) 'raw))
+	;; Enter the raw mode.
+	(rmail-mime-raw-mode entity)
+      ;; Enter the shown mode.
+      (rmail-mime-shown-mode entity))
+    (let ((inhibit-read-only t)
+	  (modified (buffer-modified-p)))
+      (save-excursion
+	(goto-char (aref segment 1))
+	(rmail-mime-insert entity)
+	(restore-buffer-modified-p modified)))))
+
+(defun rmail-mime-toggle-hidden ()
+  "Toggle on and off the hidden display mode of MIME-entity ENTITY."
+  (interactive)
+  (when (rmail-mime-message-p)
+    (let* ((rmail-mime-mbox-buffer rmail-view-buffer)
+	   (rmail-mime-view-buffer (current-buffer))
+	   (pos (if (eobp) (1- (point-max)) (point)))
+	   (entity (get-text-property pos 'rmail-mime-entity))
+	   (current (aref (rmail-mime-entity-display entity) 0))
+	   (segment (rmail-mime-entity-segment pos entity)))
+      (if (aref current 2)
+	  ;; Enter the hidden mode.
+	  (progn
+	    ;; If point is in the body part, move it to the tagline
+	    ;; (or the header if headline is not displayed).
+	    (if (= (aref segment 0) 3)
+		(goto-char (aref segment 2)))
+	    (rmail-mime-hidden-mode entity t)
+	    ;; If the current entity is the topmost one, display the
+	    ;; header.
+	    (if (and rmail-mime-mbox-buffer (= (aref segment 1) (point-min)))
+		(let ((new (aref (rmail-mime-entity-display entity) 1)))
+		  (aset new 0 t))))
+	;; Enter the shown mode.
+	(aset (rmail-mime-entity-body entity) 2 t)
+	(rmail-mime-shown-mode entity))
+      (let ((inhibit-read-only t)
+	    (modified (buffer-modified-p))
+	    (rmail-mime-mbox-buffer rmail-view-buffer)
+	    (rmail-mime-view-buffer rmail-buffer))
+	(save-excursion
+	  (goto-char (aref segment 1))
+	  (rmail-mime-insert entity)
+	  (restore-buffer-modified-p modified))))))
+
+(define-key rmail-mode-map "\t" 'rmail-mime-next-item)
+(define-key rmail-mode-map [backtab] 'rmail-mime-previous-item)
+(define-key rmail-mode-map "\r" 'rmail-mime-toggle-hidden)
+
 ;;; Handlers
 
+(defun rmail-mime-insert-tagline (entity &rest item-list)
+  "Insert a tag line for MIME-entity ENTITY.
+ITEM-LIST is a list of strings or button-elements (list) to be added
+to the tag line."
+  (insert "[")
+  (let ((tag (aref (rmail-mime-entity-tagline entity) 0)))
+    (if (> (length tag) 0) (insert (substring tag 1) ":")))
+  (insert (car (rmail-mime-entity-type entity)))
+  (dolist (item item-list)
+    (when item
+      (if (stringp item)
+	  (insert item)
+	(apply 'insert-button item))))
+  (insert "]\n"))
+  
+(defun rmail-mime-insert-header (header)
+  "Decode and insert a MIME-entity header HEADER in the current buffer.
+HEADER is a vector [BEG END DEFAULT-STATUS].
+See `rmail-mime-entity' for the detail."
+  (let ((pos (point))
+	(last-coding-system-used nil))
+    (save-restriction
+      (narrow-to-region pos pos)
+      (with-current-buffer rmail-mime-mbox-buffer
+	(let ((rmail-buffer rmail-mime-mbox-buffer)
+	      (rmail-view-buffer rmail-mime-view-buffer))
+	  (save-excursion
+	    (goto-char (aref header 0))
+	    (rmail-copy-headers (point) (aref header 1)))))
+      (rfc2047-decode-region pos (point))
+      (if (and last-coding-system-used (not rmail-mime-coding-system))
+	  (setq rmail-mime-coding-system last-coding-system-used))
+      (goto-char (point-min))
+      (rmail-highlight-headers)
+      (goto-char (point-max))
+      (insert "\n"))))
+
 (defun rmail-mime-text-handler (content-type
 				content-disposition
 				content-transfer-encoding)
   "Handle the current buffer as a plain text MIME part."
-  (let* ((charset (cdr (assq 'charset (cdr content-type))))
-	 (coding-system (when charset
-			  (intern (downcase charset)))))
-    (when (coding-system-p coding-system)
-      (decode-coding-region (point-min) (point-max) coding-system))))
-
-(defun rmail-mime-insert-text (entity)
-  "Insert MIME-entity ENTITY as a plain text MIME part in the current buffer."
+  (rmail-mime-insert-text
+   (rmail-mime-entity content-type content-disposition
+		      content-transfer-encoding
+		      (vector (vector nil nil nil) (vector nil nil t))
+		      (vector nil nil nil) (vector "" (cons nil nil) t)
+		      (vector nil nil nil) nil 'rmail-mime-insert-text))
+  t)
+
+(defun rmail-mime-insert-decoded-text (entity)
+  "Decode and insert the text body of MIME-entity ENTITY."
   (let* ((content-type (rmail-mime-entity-type entity))
 	 (charset (cdr (assq 'charset (cdr content-type))))
-	 (coding-system (if charset (intern (downcase charset))))
-	 (transfer-encoding (rmail-mime-entity-transfer-encoding entity))
-	 (body (rmail-mime-entity-body entity)))
-    (save-restriction
-      (narrow-to-region (point) (point))
-      (insert-buffer-substring rmail-buffer (car body) (cdr body))
-      (cond ((string= transfer-encoding "base64")
-	     (ignore-errors (base64-decode-region (point-min) (point-max))))
-	    ((string= transfer-encoding "quoted-printable")
-	     (quoted-printable-decode-region (point-min) (point-max))))
-      (if (coding-system-p coding-system)
-	  (decode-coding-region (point-min) (point-max) coding-system)))))
+	 (coding-system (if charset
+			    (coding-system-from-name charset)))
+	 (body (rmail-mime-entity-body entity))
+	 (pos (point)))
+    (or (and coding-system (coding-system-p coding-system))
+	(setq coding-system 'undecided))
+    (if (stringp (aref body 0))
+	(insert (aref body 0))
+      (let ((transfer-encoding (rmail-mime-entity-transfer-encoding entity)))
+	(insert-buffer-substring rmail-mime-mbox-buffer
+				 (aref body 0) (aref body 1))
+	(cond ((string= transfer-encoding "base64")
+	       (ignore-errors (base64-decode-region pos (point))))
+	      ((string= transfer-encoding "quoted-printable")
+	       (quoted-printable-decode-region pos (point))))))
+    (decode-coding-region pos (point) coding-system)
+    (or rmail-mime-coding-system
+	(setq rmail-mime-coding-system coding-system))
+    (or (bolp) (insert "\n"))))
+
+(defun rmail-mime-insert-text (entity)
+  "Presentation handler for a plain text MIME entity."
+  (let ((current (aref (rmail-mime-entity-display entity) 0))
+	(new (aref (rmail-mime-entity-display entity) 1))
+	(header (rmail-mime-entity-header entity))
+	(tagline (rmail-mime-entity-tagline entity))
+	(body (rmail-mime-entity-body entity))
+	(beg (point))
+	(segment (rmail-mime-entity-segment (point) entity)))
+
+    (or (integerp (aref body 0))
+	(let ((data (buffer-string)))
+	  (aset body 0 data)
+	  (delete-region (point-min) (point-max))))
+
+    ;; header
+    (if (eq (aref current 0) (aref new 0))
+	(goto-char (aref segment 2))
+      (if (aref current 0)
+	  (delete-char (- (aref segment 2) (aref segment 1))))
+      (if (aref new 0)
+	  (rmail-mime-insert-header header)))
+    ;; tagline
+    (if (eq (aref current 1) (aref new 1))
+	(forward-char (- (aref segment 3) (aref segment 2)))
+      (if (aref current 1)
+	  (delete-char (- (aref segment 3) (aref segment 2))))
+      (if (aref new 1)
+	  (rmail-mime-insert-tagline entity)))
+    ;; body
+    (if (eq (aref current 2) (aref new 2))
+	(forward-char (- (aref segment 4) (aref segment 3)))
+      (if (aref current 2)
+	  (delete-char (- (aref segment 4) (aref segment 3))))
+      (if (aref new 2)
+	  (rmail-mime-insert-decoded-text entity)))
+    (put-text-property beg (point) 'rmail-mime-entity entity)))
 
 ;; FIXME move to the test/ directory?
 (defun test-rmail-mime-handler ()
@@ -264,35 +574,35 @@ MIME-Version: 1.0
     (set-buffer-multibyte t)))
 
 
-(defun rmail-mime-insert-image (type data)
-  "Insert an image of type TYPE, where DATA is the image data.
-If DATA is not a string, it is a MIME-entity object."
-  (end-of-line)
-  (let ((modified (buffer-modified-p)))
-    (insert ?\n)
-    (unless (stringp data)
-      ;; DATA is a MIME-entity.
-      (let ((transfer-encoding (rmail-mime-entity-transfer-encoding data))
-	    (body (rmail-mime-entity-body data))
-	    (mbox-buffer rmail-view-buffer))
+(defun rmail-mime-insert-image (entity)
+  "Decode and insert the image body of MIME-entity ENTITY."
+  (let* ((content-type (car (rmail-mime-entity-type entity)))
+	 (bulk-data (aref (rmail-mime-entity-tagline entity) 1))
+	 (body (rmail-mime-entity-body entity))
+	 data)
+    (if (stringp (aref body 0))
+	(setq data (aref body 0))
+      (let ((rmail-mime-mbox-buffer rmail-view-buffer)
+	    (transfer-encoding (rmail-mime-entity-transfer-encoding entity)))
 	(with-temp-buffer
 	  (set-buffer-multibyte nil)
 	  (setq buffer-undo-list t)
-	  (insert-buffer-substring mbox-buffer (car body) (cdr body))
+	  (insert-buffer-substring rmail-mime-mbox-buffer
+				   (aref body 0) (aref body 1))
 	  (cond ((string= transfer-encoding "base64")
 		 (ignore-errors (base64-decode-region (point-min) (point-max))))
 		((string= transfer-encoding "quoted-printable")
 		 (quoted-printable-decode-region (point-min) (point-max))))
 	  (setq data
 		(buffer-substring-no-properties (point-min) (point-max))))))
-    (insert-image (create-image data type t))
-    (set-buffer-modified-p modified)))
+    (insert-image (create-image data (cdr bulk-data) t))
+    (insert "\n")))
 
 (defun rmail-mime-image (button)
   "Display the image associated with BUTTON."
-  (let ((inhibit-read-only t))
-    (rmail-mime-insert-image (button-get button 'image-type)
-			     (button-get button 'image-data))))
+  (save-excursion
+    (goto-char (button-end button))
+    (rmail-mime-toggle-hidden)))
 
 (define-button-type 'rmail-mime-image 'action 'rmail-mime-image)
 
@@ -305,15 +615,60 @@ For images that Emacs is capable of displaying, the behavior
 depends upon the value of `rmail-mime-show-images'."
   (rmail-mime-insert-bulk
    (rmail-mime-entity content-type content-disposition content-transfer-encoding
-		      nil nil nil)))
+		      (vector (vector nil nil nil) (vector nil t nil))
+		      (vector nil nil nil) (vector "" (cons nil nil) t)
+		      (vector nil nil nil) nil 'rmail-mime-insert-bulk)))
+
+(defun rmail-mime-set-bulk-data (entity)
+  "Setup the information about the attachment object for MIME-entity ENTITY.
+The value is non-nil if and only if the attachment object should be shown
+directly."
+  (let ((content-type (car (rmail-mime-entity-type entity)))
+	(size (cdr (assq 'size (cdr (rmail-mime-entity-disposition entity)))))
+	(bulk-data (aref (rmail-mime-entity-tagline entity) 1))
+	(body (rmail-mime-entity-body entity))
+	size type to-show)
+    (cond (size
+	   (setq size (string-to-number size)))
+	  ((stringp (aref body 0))
+	   (setq size (length (aref body 0))))
+	  (t
+	   ;; Rough estimation of the size.
+	   (let ((encoding (rmail-mime-entity-transfer-encoding entity)))
+	     (setq size (- (aref body 1) (aref body 0)))
+	     (cond ((string= encoding "base64")
+		    (setq size (/ (* size 3) 4)))
+		   ((string= encoding "quoted-printable")
+		    (setq size (/ (* size 7) 3)))))))
+
+    (cond
+     ((string-match "text/" content-type)
+      (setq type 'text))
+     ((string-match "image/\\(.*\\)" content-type)
+      (setq type (image-type-from-file-name
+		  (concat "." (match-string 1 content-type))))
+      (if (and (memq type image-types)
+	       (image-type-available-p type))
+	  (if (and rmail-mime-show-images
+		   (not (eq rmail-mime-show-images 'button))
+		   (or (not (numberp rmail-mime-show-images))
+		       (< size rmail-mime-show-images)))
+	      (setq to-show t))
+	(setq type nil))))
+    (setcar bulk-data size)
+    (setcdr bulk-data type)
+    to-show))
 
 (defun rmail-mime-insert-bulk (entity)
-  "Inesrt a MIME-entity ENTITY as an attachment.
-The optional second arg DATA, if non-nil, is a string containing
-the attachment data that is already decoded."
+  "Presentation handler for an attachment MIME entity."
   ;; Find the default directory for this media type.
   (let* ((content-type (rmail-mime-entity-type entity))
 	 (content-disposition (rmail-mime-entity-disposition entity))
+	 (current (aref (rmail-mime-entity-display entity) 0))
+	 (new (aref (rmail-mime-entity-display entity) 1))
+	 (header (rmail-mime-entity-header entity))
+	 (tagline (rmail-mime-entity-tagline entity))
+	 (bulk-data (aref tagline 1))
 	 (body (rmail-mime-entity-body entity))
 	 (directory (catch 'directory
 		      (dolist (entry rmail-mime-attachment-dirs-alist)
@@ -324,47 +679,70 @@ the attachment data that is already decoded."
 	 (filename (or (cdr (assq 'name (cdr content-type)))
 		       (cdr (assq 'filename (cdr content-disposition)))
 		       "noname"))
-	 (label (format "\nAttached %s file: " (car content-type)))
 	 (units '(B kB MB GB))
-	 data udata size osize type)
-    (if body
+	 (segment (rmail-mime-entity-segment (point) entity))
+	 beg data size)
+
+    (if (integerp (aref body 0))
 	(setq data entity
-	      udata entity
-	      size (- (cdr body) (car body)))
-      (setq data (buffer-string)
-	    udata (string-as-unibyte data)
-	    size (length udata))
-      (delete-region (point-min) (point-max)))
-    (setq osize size)
+	      size (car bulk-data))
+      (if (stringp (aref body 0))
+	  (setq data (aref body 0))
+	(setq data (string-as-unibyte (buffer-string)))
+	(aset body 0 data)
+	(rmail-mime-set-bulk-data entity)
+	(delete-region (point-min) (point-max)))
+      (setq size (length data)))
     (while (and (> size 1024.0) ; cribbed from gnus-agent-expire-done-message
 		(cdr units))
       (setq size (/ size 1024.0)
 	    units (cdr units)))
-    (insert label)
-    (insert-button filename
-		   :type 'rmail-mime-save
-		   'help-echo "mouse-2, RET: Save attachment"
-		   'filename filename
-		   'directory (file-name-as-directory directory)
-		   'data data)
-    (insert (format " (%.0f%s)" size (car units)))
-    (when (and rmail-mime-show-images
-	       (string-match "image/\\(.*\\)" (setq type (car content-type)))
-	       (setq type (concat "." (match-string 1 type))
-		     type (image-type-from-file-name type))
-	       (memq type image-types)
-	       (image-type-available-p type))
-      (insert " ")
-      (cond ((or (eq rmail-mime-show-images 'button)
-		 (and (numberp rmail-mime-show-images)
-		      (>= osize rmail-mime-show-images)))
-	     (insert-button "Display"
-			    :type 'rmail-mime-image
-			    'help-echo "mouse-2, RET: Show image"
-			    'image-type type
-			    'image-data udata))
-	    (t
-	     (rmail-mime-insert-image type udata))))))
+
+    (setq beg (point))
+
+    ;; header
+    (if (eq (aref current 0) (aref new 0))
+	(goto-char (aref segment 2))
+      (if (aref current 0)
+	  (delete-char (- (aref segment 2) (aref segment 1))))
+      (if (aref new 0)
+	  (rmail-mime-insert-header header)))
+
+    ;; tagline
+    (if (eq (aref current 1) (aref new 1))
+	(forward-char (- (aref segment 3) (aref segment 2)))
+      (if (aref current 1)
+	  (delete-char (- (aref segment 3) (aref segment 2))))
+      (if (aref new 1)
+	  (rmail-mime-insert-tagline
+	   entity
+	   " file:"
+	   (list filename
+		 :type 'rmail-mime-save
+		 'help-echo "mouse-2, RET: Save attachment"
+		 'filename filename
+		 'directory (file-name-as-directory directory)
+		 'data data)
+	   (format " (%.0f%s)" size (car units))
+	   (if (cdr bulk-data)
+	       " ")
+	   (if (cdr bulk-data)
+	       (list "Toggle show/hide"
+		     :type 'rmail-mime-image
+		     'help-echo "mouse-2, RET: Toggle show/hide"
+		     'image-type (cdr bulk-data)
+		     'image-data data)))))
+    ;; body
+    (if (eq (aref current 2) (aref new 2))
+	(forward-char (- (aref segment 4) (aref segment 3)))
+      (if (aref current 2)
+	  (delete-char (- (aref segment 4) (aref segment 3))))
+      (if (aref new 2)
+	  (cond ((eq (cdr bulk-data) 'text)
+		 (rmail-mime-insert-decoded-text entity))
+		((cdr bulk-data)
+		 (rmail-mime-insert-image entity)))))
+    (put-text-property beg (point) 'rmail-mime-entity entity)))
 
 (defun test-rmail-mime-bulk-handler ()
   "Test of a mail used as an example in RFC 2183."
@@ -396,19 +774,21 @@ CONTENT-DISPOSITION, and CONTENT-TRANSFER-ENCODING are the values
 of the respective parsed headers.  See `rmail-mime-handle' for their
 format."
   (rmail-mime-process-multipart
-   content-type content-disposition content-transfer-encoding nil))
+   content-type content-disposition content-transfer-encoding nil)
+  t)
 
 (defun rmail-mime-process-multipart (content-type
 				     content-disposition
 				     content-transfer-encoding
-				     parse-only)
+				     parse-tag)
   "Process the current buffer as a multipart MIME body.
 
-If PARSE-ONLY is nil, modify the current buffer directly for showing
-the MIME body and return nil.
+If PARSE-TAG is nil, modify the current buffer directly for
+showing the MIME body and return nil.
 
-Otherwise, just parse the current buffer and return a list of
-MIME-entity objects.
+Otherwise, PARSE-TAG is a string indicating the depth and index
+number of the entity.  In this case, parse the current buffer and
+return a list of MIME-entity objects.
 
 The other arguments are the same as `rmail-mime-multipart-handler'."
   ;; Some MUAs start boundaries with "--", while it should start
@@ -419,6 +799,8 @@ The other arguments are the same as `rmail-mime-multipart-handler'."
   ;;    of the preceding part.
   ;; We currently don't handle that.
   (let ((boundary (cdr (assq 'boundary content-type)))
+	(subtype (cadr (split-string (car content-type) "/")))
+	(index 0)
 	beg end next entities)
     (unless boundary
       (rmail-mm-get-boundary-error-message
@@ -429,12 +811,20 @@ The other arguments are the same as `rmail-mime-multipart-handler'."
     (goto-char (point-min))
     (when (and (search-forward boundary nil t)
 	       (looking-at "[ \t]*\n"))
-      (if parse-only
+      (if parse-tag
 	  (narrow-to-region (match-end 0) (point-max))
 	(delete-region (point-min) (match-end 0))))
+
+    ;; Change content-type to the proper default one for the children.
+    (cond ((string-match "mixed" subtype)
+	   (setq content-type '("text/plain")))
+	  ((string-match "digest" subtype)
+	   (setq content-type '("message/rfc822"))))
+
     ;; Loop over all body parts, where beg points at the beginning of
     ;; the part and end points at the end of the part.  next points at
-    ;; the beginning of the next part.
+    ;; the beginning of the next part.  The current point is just
+    ;; after the boundary tag.
     (setq beg (point-min))
     (while (search-forward boundary nil t)
       (setq end (match-beginning 0))
@@ -449,17 +839,46 @@ The other arguments are the same as `rmail-mime-multipart-handler'."
 	     (rmail-mm-get-boundary-error-message
 	      "Malformed boundary" content-type content-disposition
 	      content-transfer-encoding)))
+
+      (setq index (1+ index))
       ;; Handle the part.
-      (if parse-only
+      (if parse-tag
 	  (save-restriction
 	    (narrow-to-region beg end)
-	    (setq entities (cons (rmail-mime-process nil t) entities)))
+	    (let ((child (rmail-mime-process
+			  nil (format "%s/%d" parse-tag index)
+			  content-type content-disposition)))
+	      ;; Display a tagline.
+	      (aset (aref (rmail-mime-entity-display child) 1) 1
+		    (aset (rmail-mime-entity-tagline child) 2 t))
+	      (push child entities)))
+
 	(delete-region end next)
 	(save-restriction
 	  (narrow-to-region beg end)
 	  (rmail-mime-show)))
       (goto-char (setq beg next)))
-    (nreverse entities)))
+
+    (when parse-tag
+      (setq entities (nreverse entities))
+      (if (string-match "alternative" subtype)
+	  ;; Find the best entity to show, and hide all the others.
+	  (let (best second)
+	    (dolist (child entities)
+	      (if (string= (or (car (rmail-mime-entity-disposition child))
+			       (car content-disposition))
+			   "inline")
+		  (if (string-match "text/plain"
+				    (car (rmail-mime-entity-type child)))
+		      (setq best child)
+		    (if (string-match "text/.*"
+				      (car (rmail-mime-entity-type child)))
+			(setq second child)))))
+	    (or best (not second) (setq best second))
+	    (dolist (child entities)
+	      (or (eq best child)
+		  (rmail-mime-hidden-mode child t)))))
+      entities)))
 
 (defun test-rmail-mime-multipart-handler ()
   "Test of a mail used as an example in RFC 2046."
@@ -492,6 +911,40 @@ This is the epilogue.  It is also to be ignored."))
     (insert mail)
     (rmail-mime-show t)))
 
+(defun rmail-mime-insert-multipart (entity)
+  "Presentation handler for a multipart MIME entity."
+  (let ((current (aref (rmail-mime-entity-display entity) 0))
+	(new (aref (rmail-mime-entity-display entity) 1))
+	(header (rmail-mime-entity-header entity))
+	(tagline (rmail-mime-entity-tagline entity))
+	(body (rmail-mime-entity-body entity))
+	(beg (point))
+	(segment (rmail-mime-entity-segment (point) entity)))
+    ;; header
+    (if (eq (aref current 0) (aref new 0))
+	(goto-char (aref segment 2))
+      (if (aref current 0)
+	  (delete-char (- (aref segment 2) (aref segment 1))))
+      (if (aref new 0)
+	  (rmail-mime-insert-header header)))
+    ;; tagline
+    (if (eq (aref current 1) (aref new 1))
+	(forward-char (- (aref segment 3) (aref segment 2)))
+      (if (aref current 1)
+	  (delete-char (- (aref segment 3) (aref segment 2))))
+      (if (aref new 1)
+	  (rmail-mime-insert-tagline entity)))
+
+    (put-text-property beg (point) 'rmail-mime-entity entity)
+    ;; body
+    (if (eq (aref current 2) (aref new 2))
+	(forward-char (- (aref segment 4) (aref segment 3)))
+      (if (aref current 2)
+	  (delete-char (- (aref segment 4) (aref segment 3))))
+      (if (aref new 2)
+	  (dolist (child (rmail-mime-entity-children entity))
+	    (rmail-mime-insert child))))))
+
 ;;; Main code
 
 (defun rmail-mime-handle (content-type
@@ -564,7 +1017,9 @@ The current buffer must contain a single message.  It will be
 modified."
   (rmail-mime-process show-headers nil))
 
-(defun rmail-mime-process (show-headers parse-only)
+(defun rmail-mime-process (show-headers parse-tag &optional
+					default-content-type
+					default-content-disposition)
   (let ((end (point-min))
 	content-type
 	content-transfer-encoding
@@ -595,45 +1050,76 @@ modified."
     (setq content-type
 	  (if content-type
 	      (mail-header-parse-content-type content-type)
-	    ;; FIXME: Default "message/rfc822" in a "multipart/digest"
-	    ;; according to RFC 2046.
-	    '("text/plain")))
+	    (or default-content-type '("text/plain"))))
     (setq content-disposition
 	  (if content-disposition
 	      (mail-header-parse-content-disposition content-disposition)
 	    ;; If none specified, we are free to choose what we deem
 	    ;; suitable according to RFC 2183.  We like inline.
-	    '("inline")))
+	    (or default-content-disposition '("inline"))))
     ;; Unrecognized disposition types are to be treated like
     ;; attachment according to RFC 2183.
     (unless (member (car content-disposition) '("inline" "attachment"))
       (setq content-disposition '("attachment")))
 
-    (if parse-only
-	(cond ((string-match "multipart/.*" (car content-type))
-	       (setq end (1- end))
-	       (save-restriction
-		 (let ((header (if show-headers (cons (point-min) end))))
+    (if parse-tag
+	(let* ((is-inline (string= (car content-disposition) "inline"))
+	       (header (vector (point-min) end nil))
+	       (tagline (vector parse-tag (cons nil nil) t))
+	       (body (vector end (point-max) is-inline))
+	       (new (vector (aref header 2) (aref tagline 2) (aref body 2)))
+	       children handler entity)
+	  (cond ((string-match "multipart/.*" (car content-type))
+		 (save-restriction
+		   (narrow-to-region (1- end) (point-max))
+		   (setq children (rmail-mime-process-multipart
+				   content-type
+				   content-disposition
+				   content-transfer-encoding
+				   parse-tag)
+			 handler 'rmail-mime-insert-multipart)))
+		((string-match "message/rfc822" (car content-type))
+		 (save-restriction
 		   (narrow-to-region end (point-max))
-		   (rmail-mime-entity content-type
-				      content-disposition
-				      content-transfer-encoding
-				      header nil
-				      (rmail-mime-process-multipart
-				       content-type content-disposition
-				       content-transfer-encoding t)))))
-	      ((string-match "message/rfc822" (car content-type))
-	       (or show-headers
-		   (narrow-to-region end (point-max)))
-	       (rmail-mime-process t t))
-	      (t
-	       (rmail-mime-entity content-type
-				  content-disposition
-				  content-transfer-encoding
-				  nil
-				  (cons end (point-max))
-				  nil)))
+		   (let* ((msg (rmail-mime-process t parse-tag
+						   '("text/plain") '("inline")))
+			  (msg-new (aref (rmail-mime-entity-display msg) 1)))
+		     ;; Show header of the child.
+		     (aset msg-new 0 t)
+		     (aset (rmail-mime-entity-header msg) 2 t)
+		     ;; Hide tagline of the child.
+		     (aset msg-new 1 nil)
+		     (aset (rmail-mime-entity-tagline msg) 2 nil)
+		     (setq children (list msg)
+			   handler 'rmail-mime-insert-multipart))))
+		((and is-inline (string-match "text/" (car content-type)))
+		 ;; Don't need a tagline.
+		 (aset new 1 (aset tagline 2 nil))
+		 (setq handler 'rmail-mime-insert-text))
+		(t
+		 ;; Force hidden mode.
+		 (aset new 1 (aset tagline 2 t))
+		 (aset new 2 (aset body 2 nil))
+		 (setq handler 'rmail-mime-insert-bulk)))
+	  (setq entity (rmail-mime-entity content-type
+					  content-disposition
+					  content-transfer-encoding
+					  (vector (vector nil nil nil) new)
+					  header tagline body children handler))
+	  (if (and (eq handler 'rmail-mime-insert-bulk)
+		   (rmail-mime-set-bulk-data entity))
+	      ;; Show the body.
+	      (aset new 2 (aset body 2 t)))
+	  entity)
+
       ;; Hide headers and handle the part.
+      (put-text-property (point-min) (point-max) 'rmail-mime-entity
+			 (rmail-mime-entity 
+			 content-type content-disposition
+			 content-transfer-encoding
+			 (vector (vector 'raw nil 'raw) (vector 'raw nil 'raw))
+			 (vector nil nil 'raw) (vector "" (cons nil nil) nil)
+			 (vector nil nil 'raw) nil nil))
       (save-restriction
 	(cond ((string= (car content-type) "message/rfc822")
 	       (narrow-to-region end (point-max)))
@@ -642,102 +1128,117 @@ modified."
 	(rmail-mime-handle content-type content-disposition
 			   content-transfer-encoding)))))
 
-(defun rmail-mime-insert-multipart (entity)
-  "Insert MIME-entity ENTITY of multipart type in the current buffer."
-  (let ((subtype (cadr (split-string (car (rmail-mime-entity-type entity))
-				     "/")))
-	(disposition (rmail-mime-entity-disposition entity))
-	(header (rmail-mime-entity-header entity))
-	(children (rmail-mime-entity-children entity)))
-    (if header
-	(let ((pos (point)))
-	  (or (bolp)
-	      (insert "\n"))
-	  (insert-buffer-substring rmail-buffer (car header) (cdr header))
-	  (rfc2047-decode-region pos (point))
-	  (insert "\n")))
-    (cond
-     ((string= subtype "mixed")
-      (dolist (child children)
-	(rmail-mime-insert child '("text/plain") disposition)))
-     ((string= subtype "digest")
-      (dolist (child children)
-	(rmail-mime-insert child '("message/rfc822") disposition)))
-     ((string= subtype "alternative")
-      (let (best-plain-text best-text)
-	(dolist (child children)
-	  (if (string= (or (car (rmail-mime-entity-disposition child))
-			   (car disposition))
-		       "inline")
-	      (if (string-match "text/plain"
-				(car (rmail-mime-entity-type child)))
-		  (setq best-plain-text child)
-		(if (string-match "text/.*"
-				  (car (rmail-mime-entity-type child)))
-		    (setq best-text child)))))
-	(if (or best-plain-text best-text)
-	    (rmail-mime-insert (or best-plain-text best-text))
-	  ;; No child could be handled.  Insert all.
-	  (dolist (child children)
-	    (rmail-mime-insert child nil disposition)))))
-     (t
-      ;; Unsupported subtype.  Insert all of them.
-      (dolist (child children)
-	(rmail-mime-insert child))))))
-
 (defun rmail-mime-parse ()
   "Parse the current Rmail message as a MIME message.
-The value is a MIME-entiy object (see `rmail-mime-enty-new')."
-  (save-excursion
-    (goto-char (point-min))
-    (condition-case nil
-	(rmail-mime-process nil t)
-      (error nil))))
-
-(defun rmail-mime-insert (entity &optional content-type disposition)
+The value is a MIME-entiy object (see `rmail-mime-entity')."
+  (let ((rmail-mime-mbox-buffer (if (rmail-buffers-swapped-p)
+				    rmail-view-buffer
+				  (current-buffer))))
+    ;;(condition-case err
+	(with-current-buffer rmail-mime-mbox-buffer
+	  (save-excursion
+	    (goto-char (point-min))
+	    (let* ((entity (rmail-mime-process t ""
+					       '("text/plain") '("inline")))
+		   (new (aref (rmail-mime-entity-display entity) 1)))
+	      ;; Show header.
+	      (aset new 0 (aset (rmail-mime-entity-header entity) 2 t))
+	      ;; Show tagline if and only if body is not shown.
+	      (if (aref new 2)
+		  (aset new 1 (aset (rmail-mime-entity-tagline entity) 2 nil))
+		(aset new 1 (aset (rmail-mime-entity-tagline entity) 2 t)))
+	      entity)))
+	;;(error (error (format "%s" err))))
+    ))
+
+(defun rmail-mime-insert (entity)
   "Insert a MIME-entity ENTITY in the current buffer.
 
 This function will be called recursively if multiple parts are
 available."
-  (if (rmail-mime-entity-children entity)
-      (rmail-mime-insert-multipart entity)
-    (setq content-type
-	  (or (rmail-mime-entity-type entity) content-type))
-    (setq disposition
-	  (or (rmail-mime-entity-disposition entity) disposition))
-    (if (and (string= (car disposition) "inline")
-	     (string-match "text/.*" (car content-type)))
-	(rmail-mime-insert-text entity)
-      (rmail-mime-insert-bulk entity))))
+  (let ((current (aref (rmail-mime-entity-display entity) 0))
+	(new (aref (rmail-mime-entity-display entity) 1)))
+    (if (not (eq (aref new 0) 'raw))
+	;; Not a raw-mode.  Each handler should handle it.
+	(funcall (rmail-mime-entity-handler entity) entity)
+      (let ((header (rmail-mime-entity-header entity))
+	    (tagline (rmail-mime-entity-tagline entity))
+	    (body (rmail-mime-entity-body entity))
+	    (beg (point))
+	    (segment (rmail-mime-entity-segment (point) entity)))
+	;; header
+	(if (eq (aref current 0) (aref new 0))
+	    (goto-char (aref segment 2))
+	  (if (aref current 0)
+	      (delete-char (- (aref segment 2) (aref segment 1))))
+	  (insert-buffer-substring rmail-mime-mbox-buffer
+				     (aref header 0) (aref header 1)))
+	;; tagline
+	(if (aref current 1)
+	    (delete-char (- (aref segment 3) (aref segment 2))))
+	;; body
+	(if (eq (aref current 2) (aref new 2))
+	    (forward-char (- (aref segment 4) (aref segment 3)))
+	  (if (aref current 2)
+	      (delete-char (- (aref segment 4) (aref segment 3))))
+	  (insert-buffer-substring rmail-mime-mbox-buffer
+				   (aref body 0) (aref body 1)))
+	(put-text-property beg (point) 'rmail-mime-entity entity)))
+    (dotimes (i 3)
+      (aset current i (aref new i)))))
 
 (define-derived-mode rmail-mime-mode fundamental-mode "RMIME"
   "Major mode used in `rmail-mime' buffers."
   (setq font-lock-defaults '(rmail-font-lock-keywords t t nil nil)))
 
 ;;;###autoload
-(defun rmail-mime ()
-  "Process the current Rmail message as a MIME message.
-This creates a temporary \"*RMAIL*\" buffer holding a decoded
-copy of the message.  Inline content-types are handled according to
+(defun rmail-mime (&optional arg)
+  "Toggle displaying of a MIME message.
+
+The actualy behavior depends on the value of `rmail-enable-mime'.
+
+If `rmail-enable-mime' is t (default), this command change the
+displaying of a MIME message between decoded presentation form
+and raw data.
+
+With ARG, toggle the displaying of the current MIME entity only.
+
+If `rmail-enable-mime' is nil, this creates a temporary
+\"*RMAIL*\" buffer holding a decoded copy of the message.  Inline
+content-types are handled according to
 `rmail-mime-media-type-handlers-alist'.  By default, this
 displays text and multipart messages, and offers to download
 attachments as specfied by `rmail-mime-attachment-dirs-alist'."
-  (interactive)
-  (let ((data (rmail-apply-in-message rmail-current-message 'buffer-string))
-	(buf (get-buffer-create "*RMAIL*")))
-    (set-buffer buf)
-    (setq buffer-undo-list t)
-    (let ((inhibit-read-only t))
-      ;; Decoding the message in fundamental mode for speed, only
-      ;; switching to rmail-mime-mode at the end for display.  Eg
-      ;; quoted-printable-decode-region gets very slow otherwise (Bug#4993).
-      (fundamental-mode)
-      (erase-buffer)
-      (insert data)
-      (rmail-mime-show t)
-      (rmail-mime-mode)
-      (set-buffer-modified-p nil))
-    (view-buffer buf)))
+  (interactive "P")
+  (if rmail-enable-mime
+      (if (rmail-mime-message-p)
+	  (let ((rmail-mime-mbox-buffer rmail-view-buffer)
+		(rmail-mime-view-buffer rmail-buffer)
+		(entity (get-text-property (point) 'rmail-mime-entity)))
+	    (if arg
+		(if entity
+		    (rmail-mime-toggle-raw entity))
+	      (goto-char (point-min))
+	      (rmail-mime-toggle-raw
+	       (get-text-property (point) 'rmail-mime-entity))))
+	(message "Not a MIME message"))
+    (let* ((data (rmail-apply-in-message rmail-current-message 'buffer-string))
+	   (buf (get-buffer-create "*RMAIL*"))
+	   (rmail-mime-mbox-buffer rmail-view-buffer)
+	   (rmail-mime-view-buffer buf))
+      (set-buffer buf)
+      (setq buffer-undo-list t)
+      (let ((inhibit-read-only t))
+	;; Decoding the message in fundamental mode for speed, only
+	;; switching to rmail-mime-mode at the end for display.  Eg
+	;; quoted-printable-decode-region gets very slow otherwise (Bug#4993).
+	(fundamental-mode)
+	(erase-buffer)
+	(insert data)
+	(rmail-mime-show t)
+	(rmail-mime-mode)
+	(set-buffer-modified-p nil))
+      (view-buffer buf))))
 
 (defun rmail-mm-get-boundary-error-message (message type disposition encoding)
   "Return MESSAGE with more information on the main mime components."
@@ -746,34 +1247,39 @@ attachments as specfied by `rmail-mime-attachment-dirs-alist'."
 
 (defun rmail-show-mime ()
   "Function to set in `rmail-show-mime-function' (which see)."
-  (let ((mbox-buf rmail-buffer)
-	(entity (rmail-mime-parse)))
+  (let ((entity (rmail-mime-parse))
+	(rmail-mime-mbox-buffer rmail-buffer)
+	(rmail-mime-view-buffer rmail-view-buffer)
+	(rmail-mime-coding-system nil))
     (if entity
-	(with-current-buffer rmail-view-buffer
-	  (let ((inhibit-read-only t)
-		(rmail-buffer mbox-buf))
-	    (erase-buffer)
-	    (rmail-mime-insert entity)))
+	(with-current-buffer rmail-mime-view-buffer
+	  (erase-buffer)
+	  (rmail-mime-insert entity)
+	  (if rmail-mime-coding-system
+	      (set-buffer-file-coding-system rmail-mime-coding-system t t)))
       ;; Decoding failed.  Insert the original message body as is.
-      (let ((region (with-current-buffer mbox-buf
+      (let ((region (with-current-buffer rmail-mime-mbox-buffer
 		      (goto-char (point-min))
 		      (re-search-forward "^$" nil t)
 		      (forward-line 1)
 		      (cons (point) (point-max)))))
-	(with-current-buffer rmail-view-buffer
+	(with-current-buffer rmail-mime-view-buffer
 	  (let ((inhibit-read-only t))
 	    (erase-buffer)
-	    (insert-buffer-substring mbox-buf (car region) (cdr region))))
+	    (insert-buffer-substring rmail-mime-mbox-buffer
+				     (car region) (cdr region))))
+	(set-buffer-file-coding-system 'no-conversion t t)
 	(message "MIME decoding failed")))))
 
 (setq rmail-show-mime-function 'rmail-show-mime)
 
 (defun rmail-insert-mime-forwarded-message (forward-buffer)
   "Function to set in `rmail-insert-mime-forwarded-message-function' (which see)."
-  (let ((mbox-buf (with-current-buffer forward-buffer rmail-view-buffer)))
+  (let ((rmail-mime-mbox-buffer
+	 (with-current-buffer forward-buffer rmail-view-buffer)))
     (save-restriction
       (narrow-to-region (point) (point))
-      (message-forward-make-body-mime mbox-buf))))
+      (message-forward-make-body-mime rmail-mime-mbox-buffer))))
 
 (setq rmail-insert-mime-forwarded-message-function
       'rmail-insert-mime-forwarded-message)
@@ -794,15 +1300,16 @@ attachments as specfied by `rmail-mime-attachment-dirs-alist'."
   "Function to set in `rmail-search-mime-message-function' (which see)."
   (save-restriction
     (narrow-to-region (rmail-msgbeg msg) (rmail-msgend msg))
-    (let ((mbox-buf (current-buffer))
-	  (header-end (save-excursion
-			(re-search-forward "^$" nil 'move) (point)))
-	  (body-end (point-max))
-	  (entity (rmail-mime-parse)))
+    (let* ((rmail-mime-mbox-buffer (current-buffer))
+	   (rmail-mime-view-buffer rmail-view-buffer)
+	   (header-end (save-excursion
+			 (re-search-forward "^$" nil 'move) (point)))
+	   (body-end (point-max))
+	   (entity (rmail-mime-parse)))
       (or 
        ;; At first, just search the headers.
        (with-temp-buffer
-	 (insert-buffer-substring mbox-buf nil header-end)
+	 (insert-buffer-substring rmail-mime-mbox-buffer nil header-end)
 	 (rfc2047-decode-region (point-min) (point))
 	 (goto-char (point-min))
 	 (re-search-forward regexp nil t))
@@ -815,8 +1322,7 @@ attachments as specfied by `rmail-mime-attachment-dirs-alist'."
 			   (not (string= (downcase charset) "us-ascii"))))))
 	   ;; Search the decoded MIME message.
 	   (with-temp-buffer
-	     (let ((rmail-buffer mbox-buf))
-	       (rmail-mime-insert entity))
+	     (rmail-mime-insert entity)
 	     (goto-char (point-min))
 	     (re-search-forward regexp nil t))
 	 ;; Search the body without decoding.