Adding multipart indicator on summary line

[Makoto Fujiwara <makoto@ki.nu>]

Hi, I'm testing attached modification to show 
another sign if the mail is multipart/signed or multipart/encrypted.

I have also following line in ~/.wl to utilize this feature.

;      wl-summary-line-format "%n%T%P   %M/%D(%W)%h:%m %t%[%17(%c %f%) %] %s"
 (setq wl-summary-line-format "%n%T%P%1@%M/%D(%W)%h:%m %t%[%17(%c %f%) %] %s")

But (probably) related this I'm getting followng message.

wl-summary-goto-folder-subr: Invalid function: wl-folder-get-entity-id

Please advice me, thank you.
---
Makoto Fujiwara, 
Chiba, Japan, Narita Airport and Disneyland prefecture.

--- /usr/pkg/share/emacs/site-lisp/wl/wl-summary.el	2013-01-08 00:22:17.000000000 +0900
+++ /home/makoto/mule/lisp/wl-summary.el	2013-01-16 09:40:36.000000000 +0900
@@ -3541,11 +3541,13 @@ Return non-nil if the mark is updated"
   (let ((content-type (elmo-message-entity-field
 		       wl-message-entity 'content-type))
 	(case-fold-search t))
-    (if (and content-type
-	     (string-match "multipart/mixed" content-type))
-	"@"
-      "")))
-
+    (if (stringp content-type)
+	(cond 
+	 ((string-match "multipart/mixed" content-type) "@")
+	 ((string-match "multipart/signed" content-type) "s")
+	 ((string-match "multipart/encrypted" content-type) "e")
+	 (t " ") )
+      " " )))
 ;;; For future use.
 ;;;(defun wl-summary-line-cached ()
 ;;;  (if (elmo-message-cached-p wl-summary-buffer-elmo-folder