(mime-preview-original-major-mode): Modify DOC-string.
[elisp/semi.git] / mime-view.el
index 2882475..5cb8d26 100644 (file)
@@ -33,6 +33,7 @@
 (require 'mime-parse)
 (require 'semi-def)
 (require 'calist)
+(require 'alist)
 (require 'mailcap)
 
 
 ;;; @@ in raw-buffer
 ;;;
 
-(defvar mime-raw-message-info
+(defvar mime-raw-message-info nil
   "Information about structure of message.
 Please use reference function `mime-entity-SLOT' to get value of SLOT.
 
 Following is a list of slots of the structure:
 
-node-id                reversed entity-number (list of integers)
-point-min      beginning point of region in raw-buffer
-point-max      end point of region in raw-buffer
-type           media-type (symbol)
-subtype                media-subtype (symbol)
-type/subtype   media-type/subtype (string or nil)
-parameters     parameter of Content-Type field (association list)
-encoding       Content-Transfer-Encoding (string or nil)
-children       entities included in this entity (list of content-infos)
+buffer                 buffer includes this entity (buffer).
+node-id                        node-id (list of integers)
+header-start           minimum point of header in raw-buffer
+header-end             maximum point of header in raw-buffer
+body-start             minimum point of body in raw-buffer
+body-end               maximum point of body in raw-buffer
+content-type           content-type (content-type)
+content-disposition    content-disposition (content-disposition)
+encoding               Content-Transfer-Encoding (string or nil)
+children               entities included in this entity (list of entity)
 
 If an entity includes other entities in its body, such as multipart or
 message/rfc822, `mime-entity' structures of them are included in
 `children', so the `mime-entity' structure become a tree.")
 (make-variable-buffer-local 'mime-raw-message-info)
 
+
 (defvar mime-preview-buffer nil
   "MIME-preview buffer corresponding with the (raw) buffer.")
 (make-variable-buffer-local 'mime-preview-buffer)
 
+
+(defvar mime-raw-representation-type nil
+  "Representation-type of mime-raw-buffer.
+It must be nil, `binary' or `cooked'.
+If it is nil, `mime-raw-representation-type-alist' is used as default
+value.
+Notice that this variable is usually used as buffer local variable in
+raw-buffer.")
+
+(make-variable-buffer-local 'mime-raw-representation-type)
+
 (defvar mime-raw-representation-type-alist
   '((mime-show-message-mode     . binary)
     (mime-temp-message-mode     . binary)
@@ -120,10 +134,6 @@ message/partial, it is called `mother-buffer'.")
   "Raw buffer corresponding with the (MIME-preview) buffer.")
 (make-variable-buffer-local 'mime-raw-buffer)
 
-(defvar mime-preview-original-major-mode nil
-  "Major-mode of mime-raw-buffer.")
-(make-variable-buffer-local 'mime-preview-original-major-mode)
-
 (defvar mime-preview-original-window-configuration nil
   "Window-configuration before mime-view-mode is called.")
 (make-variable-buffer-local 'mime-preview-original-window-configuration)
@@ -175,6 +185,62 @@ If optional argument MESSAGE-INFO is not specified,
            (setq children (cdr children)))
          message-info))))
 
+
+(defsubst mime-entity-parent (entity &optional message-info)
+  "Return mother entity of ENTITY.
+If optional argument MESSAGE-INFO is not specified,
+`mime-raw-message-info' in buffer of ENTITY is used."
+  (mime-raw-find-entity-from-node-id
+   (cdr (mime-entity-node-id entity))
+   (or message-info
+       (save-excursion
+        (set-buffer (mime-entity-buffer entity))
+        mime-raw-message-info))))
+
+(defsubst mime-entity-situation (entity)
+  "Return situation of ENTITY."
+  (append (or (mime-entity-content-type entity)
+             (make-mime-content-type 'text 'plain))
+         (list (cons 'encoding (mime-entity-encoding entity))
+               (cons 'major-mode
+                     (save-excursion
+                       (set-buffer (mime-entity-buffer entity))
+                       major-mode)))
+         ))
+
+
+(defvar mime-view-uuencode-encoding-name-list '("x-uue" "x-uuencode"))
+
+(defun mime-raw-get-uu-filename ()
+  (save-excursion
+    (if (re-search-forward "^begin [0-9]+ " nil t)
+       (if (looking-at ".+$")
+           (buffer-substring (match-beginning 0)(match-end 0))
+         ))))
+
+(defun mime-raw-get-subject (entity)
+  (or (std11-find-field-body '("Content-Description" "Subject"))
+      (let ((ret (mime-entity-content-disposition entity)))
+       (and ret
+            (setq ret (mime-content-disposition-filename ret))
+            (std11-strip-quoted-string ret)
+            ))
+      (let ((ret (mime-entity-content-type entity)))
+       (and ret
+            (setq ret
+                  (cdr
+                   (let ((param (mime-content-type-parameters ret)))
+                     (or (assoc "name" param)
+                         (assoc "x-name" param))
+                     )))
+            (std11-strip-quoted-string ret)
+            ))
+      (if (member (mime-entity-encoding entity)
+                 mime-view-uuencode-encoding-name-list)
+         (mime-raw-get-uu-filename))
+      ""))
+
+
 (defsubst mime-raw-point-to-entity-node-id (point &optional message-info)
   "Return entity-node-id from POINT in mime-raw-buffer.
 If optional argument MESSAGE-INFO is not specified,
@@ -185,14 +251,7 @@ If optional argument MESSAGE-INFO is not specified,
   "Return entity-number from POINT in mime-raw-buffer.
 If optional argument MESSAGE-INFO is not specified,
 `mime-raw-message-info' is used."
-  (reverse (mime-raw-point-to-entity-node-id point message-info)))
-
-(defsubst mime-raw-entity-parent (entity &optional message-info)
-  "Return mother entity of ENTITY.
-If optional argument MESSAGE-INFO is not specified,
-`mime-raw-message-info' is used."
-  (mime-raw-find-entity-from-node-id (cdr (mime-entity-node-id entity))
-                                    message-info))
+  (mime-entity-number (mime-raw-find-entity-from-point point message-info)))
 
 (defun mime-raw-flatten-message-info (&optional message-info)
   "Return list of entity in mime-raw-buffer.
@@ -217,7 +276,7 @@ If optional argument MESSAGE-INFO is not specified,
 ;;; @@@ predicate function
 ;;;
 
-(defun mime-view-entity-button-visible-p (entity message-info)
+(defun mime-view-entity-button-visible-p (entity)
   "Return non-nil if header of ENTITY is visible.
 Please redefine this function if you want to change default setting."
   (let ((media-type (mime-entity-media-type entity))
@@ -225,8 +284,7 @@ Please redefine this function if you want to change default setting."
     (or (not (eq media-type 'application))
        (and (not (eq media-subtype 'x-selection))
             (or (not (eq media-subtype 'octet-stream))
-                (let ((mother-entity
-                       (mime-raw-entity-parent entity message-info)))
+                (let ((mother-entity (mime-entity-parent entity)))
                   (or (not (eq (mime-entity-media-type mother-entity)
                                'multipart))
                       (not (eq (mime-entity-media-subtype mother-entity)
@@ -237,7 +295,7 @@ Please redefine this function if you want to change default setting."
 ;;; @@@ entity button generator
 ;;;
 
-(defun mime-view-insert-entity-button (entity message-info subj)
+(defun mime-view-insert-entity-button (entity subject)
   "Insert entity-button of ENTITY."
   (let ((entity-node-id (mime-entity-node-id entity))
        (params (mime-entity-parameters entity)))
@@ -257,12 +315,12 @@ Please redefine this function if you want to change default setting."
                (setq access-type (cdr access-type))
                (if server
                    (format "%s %s ([%s] %s)"
-                           num subj access-type (cdr server))
+                           num subject access-type (cdr server))
                (let ((site (cdr (assoc "site" params)))
                      (dir (cdr (assoc "directory" params)))
                      )
                  (format "%s %s ([%s] %s:%s)"
-                         num subj access-type site dir)
+                         num subject access-type site dir)
                  )))
            )
           (t
@@ -271,7 +329,7 @@ Please redefine this function if you want to change default setting."
                  (charset (cdr (assoc "charset" params)))
                  (encoding (mime-entity-encoding entity)))
              (concat
-              num " " subj
+              num " " subject
               (let ((rest
                      (format " <%s/%s%s%s>"
                              media-type media-subtype
@@ -432,6 +490,12 @@ Each elements are regexp of field-name.")
    (body-presentation-method . mime-preview-text/plain)))
 
 (ctree-set-calist-strictly
+ 'mime-preview-condition
+ '((type . multipart)(subtype . alternative)
+   (body . visible)
+   (body-presentation-method . mime-preview-multipart/alternative)))
+
+(ctree-set-calist-strictly
  'mime-preview-condition '((type . message)(subtype . partial)
                           (body-presentation-method
                            . mime-preview-message/partial-button)))
@@ -485,12 +549,89 @@ Each elements are regexp of field-name.")
        (default-situation
          (cdr (assq 'childrens-situation situation))))
     (while children
-      (mime-view-display-entity (car children) message-info
-                               mime-raw-buffer (current-buffer)
+      (mime-view-display-entity (car children)
+                               (save-excursion
+                                 (set-buffer (mime-entity-buffer entity))
+                                 mime-raw-message-info)
+                               (current-buffer)
                                default-situation)
       (setq children (cdr children))
       )))
 
+(defcustom mime-view-type-subtype-score-alist
+  '(((text . enriched) . 3)
+    ((text . richtext) . 2)
+    ((text . plain)    . 1)
+    (t . 0))
+  "Alist MEDIA-TYPE vs corresponding score.
+MEDIA-TYPE must be (TYPE . SUBTYPE), TYPE or t.  t means default."
+  :group 'mime-view
+  :type '(repeat (cons (choice :tag "Media-Type"
+                              (item :tag "Type/Subtype"
+                                    (cons symbol symbol))
+                              (item :tag "Type" symbol)
+                              (item :tag "Default" t))
+                      integer)))
+
+(defun mime-preview-multipart/alternative (entity situation)
+  (let* ((children (mime-entity-children entity))
+        (default-situation
+          (cdr (assq 'childrens-situation situation)))
+        (i 0)
+        (p 0)
+        (max-score 0)
+        (situations
+         (mapcar (function
+                  (lambda (child)
+                    (let ((situation
+                           (or (ctree-match-calist
+                                mime-preview-condition
+                                (append (mime-entity-situation child)
+                                        default-situation))
+                               default-situation)))
+                      (if (cdr (assq 'body-presentation-method situation))
+                          (let ((score
+                                 (cdr
+                                  (or (assoc
+                                       (cons
+                                        (cdr (assq 'type situation))
+                                        (cdr (assq 'subtype situation)))
+                                       mime-view-type-subtype-score-alist)
+                                      (assq
+                                       (cdr (assq 'type situation))
+                                       mime-view-type-subtype-score-alist)
+                                      (assq
+                                       t
+                                       mime-view-type-subtype-score-alist)
+                                      ))))
+                            (if (> score max-score)
+                                (setq p i
+                                      max-score score)
+                              )))
+                      (setq i (1+ i))
+                      situation)
+                    ))
+                 children)))
+    (setq i 0)
+    (while children
+      (let ((child (car children))
+           (situation (car situations)))
+       (mime-view-display-entity child
+                                 (save-excursion
+                                   (set-buffer (mime-entity-buffer child))
+                                   mime-raw-message-info)
+                                 (current-buffer)
+                                 default-situation
+                                 (if (= i p)
+                                     situation
+                                   (del-alist 'body-presentation-method
+                                              (copy-alist situation))))
+       )
+      (setq children (cdr children)
+           situations (cdr situations)
+           i (1+ i))
+      )))
+
 
 ;;; @ acting-condition
 ;;;
@@ -678,61 +819,18 @@ The compressed face will be piped to this command.")
          ))))
 
 
-;;; @ miscellaneous
-;;;
-
-(defvar mime-view-uuencode-encoding-name-list '("x-uue" "x-uuencode"))
-
-
 ;;; @ buffer setup
 ;;;
 
-(defvar mime-view-redisplay nil)
-
-(defun mime-view-setup-buffers (&optional ctl encoding ibuf obuf)
-  (if ibuf
-      (progn
-       (get-buffer ibuf)
-       (set-buffer ibuf)
-       ))
-  (or mime-view-redisplay
-      (setq mime-raw-message-info (mime-parse-message ctl encoding))
-      )
-  (let ((message-info mime-raw-message-info)
-       (the-buf (current-buffer))
-       (mode major-mode))
-    (or obuf
-       (setq obuf (concat "*Preview-" (buffer-name the-buf) "*")))
-    (set-buffer (get-buffer-create obuf))
-    (let ((inhibit-read-only t))
-      ;;(setq buffer-read-only nil)
-      (widen)
-      (erase-buffer)
-      (setq mime-raw-buffer the-buf)
-      (setq mime-preview-original-major-mode mode)
-      (setq major-mode 'mime-view-mode)
-      (setq mode-name "MIME-View")
-      (mime-view-display-entity message-info message-info
-                               the-buf obuf
-                               '((entity-button . invisible)
-                                 (header . visible)
-                                 ))
-      (set-buffer-modified-p nil)
-      )
-    (setq buffer-read-only t)
-    (set-buffer the-buf)
-    )
-  (setq mime-preview-buffer obuf)
-  )
-
-(defun mime-view-display-entity (entity message-info ibuf obuf
-                                       default-situation)
-  (let* ((start (mime-entity-point-min entity))
+(defun mime-view-display-entity (entity message-info obuf
+                                       default-situation
+                                       &optional situation)
+  (let* ((raw-buffer (mime-entity-buffer entity))
+        (start (mime-entity-point-min entity))
         (end (mime-entity-point-max entity))
-         (content-type (mime-entity-content-type entity))
-         (encoding (mime-entity-encoding entity))
-        end-of-header e nb ne subj)
-    (set-buffer ibuf)
+        original-major-mode end-of-header e nb ne subj)
+    (set-buffer raw-buffer)
+    (setq original-major-mode major-mode)
     (goto-char start)
     (setq end-of-header (if (re-search-forward "^$" nil t)
                            (1+ (match-end 0))
@@ -744,35 +842,31 @@ The compressed face will be piped to this command.")
       (narrow-to-region start end)
       (setq subj (eword-decode-string (mime-raw-get-subject entity)))
       )
-    (let* ((situation
-           (or
-            (ctree-match-calist mime-preview-condition
-                                (append
-                                 (or content-type
-                                     (make-mime-content-type 'text 'plain))
-                                 (list* (cons 'encoding   encoding)
-                                        (cons 'major-mode major-mode)
-                                        default-situation)))
-            default-situation))
-          (button-is-invisible
-           (eq (cdr (assq 'entity-button situation)) 'invisible))
-          (header-is-visible
-           (eq (cdr (assq 'header situation)) 'visible))
-          (body-presentation-method
-           (cdr (assq 'body-presentation-method situation)))
-          (children (mime-entity-children entity)))
+    (or situation
+       (setq situation
+             (or (ctree-match-calist mime-preview-condition
+                                     (append (mime-entity-situation entity)
+                                             default-situation))
+                 default-situation)))
+    (let ((button-is-invisible
+          (eq (cdr (assq 'entity-button situation)) 'invisible))
+         (header-is-visible
+          (eq (cdr (assq 'header situation)) 'visible))
+         (body-presentation-method
+          (cdr (assq 'body-presentation-method situation)))
+         (children (mime-entity-children entity)))
       (set-buffer obuf)
       (setq nb (point))
       (narrow-to-region nb nb)
       (or button-is-invisible
-         (if (mime-view-entity-button-visible-p entity message-info)
-             (mime-view-insert-entity-button entity message-info subj)
+         (if (mime-view-entity-button-visible-p entity)
+             (mime-view-insert-entity-button entity subj)
            ))
       (if header-is-visible
          (save-restriction
            (narrow-to-region (point)(point))
-           (insert-buffer-substring mime-raw-buffer start end-of-header)
-           (let ((f (cdr (assq mime-preview-original-major-mode
+           (insert-buffer-substring raw-buffer start end-of-header)
+           (let ((f (cdr (assq original-major-mode
                                mime-view-content-header-filter-alist))))
              (if (functionp f)
                  (funcall f)
@@ -784,7 +878,7 @@ The compressed face will be piped to this command.")
             (let ((body-filter (cdr (assq 'body-filter situation))))
               (save-restriction
                 (narrow-to-region (point-max)(point-max))
-                (insert-buffer-substring mime-raw-buffer end-of-header end)
+                (insert-buffer-substring raw-buffer end-of-header end)
                 (funcall body-filter situation)
                 )))
            (children)
@@ -794,7 +888,7 @@ The compressed face will be piped to this command.")
            (t
             (when button-is-invisible
               (goto-char (point-max))
-              (mime-view-insert-entity-button entity message-info subj)
+              (mime-view-insert-entity-button entity subj)
               )
             (or header-is-visible
                 (progn
@@ -804,43 +898,15 @@ The compressed face will be piped to this command.")
             ))
       (setq ne (point-max))
       (widen)
-      (put-text-property nb ne 'mime-view-raw-buffer ibuf)
       (put-text-property nb ne 'mime-view-entity entity)
       (goto-char ne)
       (if children
-         (mime-preview-multipart/mixed entity situation)
-       )
+         (if (functionp body-presentation-method)
+             (funcall body-presentation-method entity situation)
+           (mime-preview-multipart/mixed entity situation)
+           ))
       )))
 
-(defun mime-raw-get-uu-filename ()
-  (save-excursion
-    (if (re-search-forward "^begin [0-9]+ " nil t)
-       (if (looking-at ".+$")
-           (buffer-substring (match-beginning 0)(match-end 0))
-         ))))
-
-(defun mime-raw-get-subject (entity)
-  (or (std11-find-field-body '("Content-Description" "Subject"))
-      (let ((ret (mime-entity-content-disposition entity)))
-       (and ret
-            (setq ret (mime-content-disposition-filename ret))
-            (std11-strip-quoted-string ret)
-            ))
-      (let ((ret (mime-entity-content-type entity)))
-       (and ret
-            (setq ret
-                  (cdr
-                   (let ((param (mime-content-type-parameters ret)))
-                     (or (assoc "name" param)
-                         (assoc "x-name" param))
-                     )))
-            (std11-strip-quoted-string ret)
-            ))
-      (if (member (mime-entity-encoding entity)
-                 mime-view-uuencode-encoding-name-list)
-         (mime-raw-get-uu-filename))
-      ""))
-
 
 ;;; @ MIME viewer mode
 ;;;
@@ -978,7 +1044,61 @@ The compressed face will be piped to this command.")
          (bury-buffer buf)
          ))))
 
-(defun mime-view-mode (&optional mother ctl encoding ibuf obuf
+(defvar mime-view-redisplay nil)
+
+(defun mime-view-display-message (message &optional preview-buffer
+                                         mother default-keymap-or-function)
+  (mime-maybe-hide-echo-buffer)
+  (let ((win-conf (current-window-configuration))
+       (raw-buffer (mime-entity-buffer message)))
+    (or preview-buffer
+       (setq preview-buffer
+             (concat "*Preview-" (buffer-name raw-buffer) "*")))
+    (set-buffer raw-buffer)
+    (setq mime-raw-message-info (mime-parse-message))
+    (setq mime-preview-buffer preview-buffer)
+    (let ((inhibit-read-only t))
+      (switch-to-buffer preview-buffer)
+      (widen)
+      (erase-buffer)
+      (setq mime-raw-buffer raw-buffer)
+      (if mother
+         (setq mime-mother-buffer mother)
+       )
+      (setq mime-preview-original-window-configuration win-conf)
+      (setq major-mode 'mime-view-mode)
+      (setq mode-name "MIME-View")
+      (mime-view-display-entity message message
+                               preview-buffer
+                               '((entity-button . invisible)
+                                 (header . visible)
+                                 ))
+      (mime-view-define-keymap default-keymap-or-function)
+      (let ((point
+            (next-single-property-change (point-min) 'mime-view-entity)))
+       (if point
+           (goto-char point)
+         (goto-char (point-min))
+         (search-forward "\n\n" nil t)
+         ))
+      (run-hooks 'mime-view-mode-hook)
+      ))
+  (set-buffer-modified-p nil)
+  (setq buffer-read-only t)
+  )
+
+(defun mime-view-buffer (&optional raw-buffer preview-buffer mother
+                                  default-keymap-or-function)
+  (interactive)
+  (mime-view-display-message
+   (save-excursion
+     (if raw-buffer (set-buffer raw-buffer))
+     (mime-parse-message)
+     )
+   preview-buffer mother default-keymap-or-function))
+
+(defun mime-view-mode (&optional mother ctl encoding
+                                raw-buffer preview-buffer
                                 default-keymap-or-function)
   "Major mode for viewing MIME message.
 
@@ -1004,27 +1124,13 @@ button-2        Move to point under the mouse cursor
                and decode current content as `play mode'
 "
   (interactive)
-  (mime-maybe-hide-echo-buffer)
-  (let ((ret (mime-view-setup-buffers ctl encoding ibuf obuf))
-       (win-conf (current-window-configuration))
-       )
-    (prog1
-       (switch-to-buffer ret)
-      (setq mime-preview-original-window-configuration win-conf)
-      (if mother
-         (progn
-           (setq mime-mother-buffer mother)
-           ))
-      (mime-view-define-keymap default-keymap-or-function)
-      (let ((point
-            (next-single-property-change (point-min) 'mime-view-entity)))
-       (if point
-           (goto-char point)
-         (goto-char (point-min))
-         (search-forward "\n\n" nil t)
-         ))
-      (run-hooks 'mime-view-mode-hook)
-      )))
+  (mime-view-display-message
+   (save-excursion
+     (if raw-buffer (set-buffer raw-buffer))
+     (or mime-view-redisplay
+        (mime-parse-message ctl encoding))
+     )
+   preview-buffer mother default-keymap-or-function))
 
 
 ;;; @@ playing
@@ -1055,16 +1161,21 @@ It decodes current entity to call internal or external method as
 ;;; @@ following
 ;;;
 
-(defun mime-preview-original-major-mode ()
+(defun mime-preview-original-major-mode (&optional recursive)
   "Return major-mode of original buffer.
-If a current buffer has mime-mother-buffer, return original major-mode
-of the mother-buffer."
-  (if mime-mother-buffer
+If optional argument RECURSIVE is non-nil and current buffer has
+mime-mother-buffer, it returns original major-mode of the
+mother-buffer."
+  (if (and recursive mime-mother-buffer)
       (save-excursion
        (set-buffer mime-mother-buffer)
-       (mime-preview-original-major-mode)
+       (mime-preview-original-major-mode recursive)
        )
-    mime-preview-original-major-mode))
+    (save-excursion
+      (set-buffer
+       (mime-entity-buffer
+       (get-text-property (point-min) 'mime-view-entity)))
+      major-mode)))
 
 (defun mime-preview-follow-current-entity ()
   "Write follow message to current entity.
@@ -1122,7 +1233,7 @@ It calls following-method selected from variable
                 (setq p-end (point-max))
                 ))
             ))
-      (let* ((mode (mime-preview-original-major-mode))
+      (let* ((mode (mime-preview-original-major-mode 'recursive))
             (new-name
              (format "%s-%s" (buffer-name) (reverse entity-node-id)))
             new-buf
@@ -1248,7 +1359,7 @@ variable `mime-view-over-to-previous-method-alist'."
          (goto-char (1- point))
          (mime-preview-move-to-previous)
          )
-      (let ((f (assq mime-preview-original-major-mode
+      (let ((f (assq (mime-preview-original-major-mode)
                     mime-view-over-to-previous-method-alist)))
        (if f
            (funcall (cdr f))
@@ -1270,7 +1381,7 @@ variable `mime-view-over-to-next-method-alist'."
          (if (null (get-text-property point 'mime-view-entity))
              (mime-preview-move-to-next)
            ))
-      (let ((f (assq mime-preview-original-major-mode
+      (let ((f (assq (mime-preview-original-major-mode)
                     mime-view-over-to-next-method-alist)))
        (if f
            (funcall (cdr f))
@@ -1286,7 +1397,7 @@ If reached to (point-max), it calls function registered in variable
       (setq h (1- (window-height)))
       )
   (if (= (point) (point-max))
-      (let ((f (assq mime-preview-original-major-mode
+      (let ((f (assq (mime-preview-original-major-mode)
                      mime-view-over-to-next-method-alist)))
         (if f
             (funcall (cdr f))
@@ -1309,24 +1420,14 @@ If reached to (point-min), it calls function registered in variable
       (setq h (1- (window-height)))
       )
   (if (= (point) (point-min))
-      (let ((f (assq mime-preview-original-major-mode
-                     mime-view-over-to-previous-method-alist)))
+      (let ((f (assq (mime-preview-original-major-mode)
+                    mime-view-over-to-previous-method-alist)))
         (if f
             (funcall (cdr f))
           ))
-    (let (point)
-      (save-excursion
-       (catch 'tag
-         (while (not (bobp))
-           (if (setq point
-                     (previous-single-property-change (point)
-                                                      'mime-view-entity))
-               (throw 'tag t)
-             )
-           (backward-char)
-           )
-         (setq point (point-min))
-         ))
+    (let ((point
+          (or (previous-single-property-change (point) 'mime-view-entity)
+              (point-min))))
       (forward-line (- h))
       (if (< (point) point)
           (goto-char point)
@@ -1351,7 +1452,7 @@ If reached to (point-min), it calls function registered in variable
 It calls function registered in variable
 `mime-preview-quitting-method-alist'."
   (interactive)
-  (let ((r (assq mime-preview-original-major-mode
+  (let ((r (assq (mime-preview-original-major-mode)
                 mime-preview-quitting-method-alist)))
     (if r
        (funcall (cdr r))
@@ -1362,7 +1463,7 @@ It calls function registered in variable
 It calls function registered in variable
 `mime-view-show-summary-method'."
   (interactive)
-  (let ((r (assq mime-preview-original-major-mode
+  (let ((r (assq (mime-preview-original-major-mode)
                 mime-view-show-summary-method)))
     (if r
        (funcall (cdr r))