[PATCH 3/3] emacs/show: use n-s-i-headerline to update tags

[David Bremner <david@tethera.net>]

Although this has more steps than the previous regular expression
search and replace, it should be more robust against changes in the
headerline format, such as the inclusion of duplicate numbers (which
broke the previous version).
---
 emacs/notmuch-show.el | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 5fb5ab31..c4e88be2 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -452,14 +452,20 @@ operation on the contents of the current buffer."
 (defun notmuch-show-update-tags (tags)
   "Update the displayed tags of the current message."
   (save-excursion
-    (goto-char (notmuch-show-message-top))
-    (when (re-search-forward "(\\([^()]*\\))$" (line-end-position) t)
-      (let ((inhibit-read-only t))
-	(replace-match (concat "("
-			       (notmuch-tag-format-tags
-				tags
-				(notmuch-show-get-prop :orig-tags))
-			       ")"))))))
+    (let ((inhibit-read-only t)
+	  (start (notmuch-show-message-top))
+	  (depth (notmuch-show-get-prop :depth))
+	  (orig-tags (notmuch-show-get-prop :orig-tags))
+	  (props (notmuch-show-get-message-properties))
+	  (extent (notmuch-show-message-extent)))
+      (goto-char start)
+      (notmuch-show-insert-headerline props depth tags orig-tags)
+      (put-text-property start (1+ start)
+			 :notmuch-message-properties props)
+      (put-text-property (car extent) (cdr extent) :notmuch-message-extent extent)
+      ;; delete original headerline, but do not save to kill ring
+      (delete-region
+       (point) (save-excursion (end-of-line nil) (1+ (point)))))))
 
 (defun notmuch-clean-address (address)
   "Try to clean a single email ADDRESS for display. Return a cons
-- 
2.35.1