-(defun mm-get-part (handle)
- "Return the contents of HANDLE as a string."
- (let ((default-enable-multibyte-characters
- (with-current-buffer (mm-handle-buffer handle)
- (mm-multibyte-p))))
- (with-temp-buffer
- (insert-buffer-substring (mm-handle-buffer handle))
- (mm-disable-multibyte)
- (mm-decode-content-transfer-encoding
- (mm-handle-encoding handle)
- (mm-handle-media-type handle))
+(defmacro mm-with-part (handle &rest forms)
+ "Run FORMS in the temp buffer containing the contents of HANDLE."
+ ;; 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))
+ (when (and (mm-handle-buffer handle)
+ (buffer-name (mm-handle-buffer handle)))
+ (with-temp-buffer
+ (mm-disable-multibyte)
+ (insert-buffer-substring (mm-handle-buffer handle))
+ (mm-decode-content-transfer-encoding
+ (mm-handle-encoding handle)
+ (mm-handle-media-type handle))
+ ,@forms))))
+(put 'mm-with-part 'lisp-indent-function 1)
+(put 'mm-with-part 'edebug-form-spec '(body))
+
+(defun mm-get-part (handle &optional no-cache)
+ "Return the contents of HANDLE as a string.
+If NO-CACHE is non-nil, cached contents of a message/external-body part
+are ignored."
+ (if (and (not no-cache)
+ (equal (mm-handle-media-type handle) "message/external-body"))
+ (progn
+ (unless (mm-handle-cache handle)
+ (mm-extern-cache-contents handle))
+ (with-current-buffer (mm-handle-buffer (mm-handle-cache handle))
+ (buffer-string)))
+ (mm-with-part handle