* wl-util.el (wl-current-message-buffer): Define as function;

* wl-util.el (wl-current-message-buffer): Define as function;
Don't use the value of wl-messge-buffer.

* wl-summary.el (wl-summary-redisplay-no-mime-internal): Update
persistent mark.

* wl-mime.el (wl-draft-yank-current-message-entity): If there's
no current message, cause an error.

* elmo-mime.el (elmo-mime-message-display): Display message entirely
if folder length is zero.
(elmo-mime-display-as-is): Ditto.

* elmo-multi.el (elmo-folder-set-message-modified): Ditto.