emacs: insert quotable parts in reply as they are displayed in show view

In reply, insert quotable parts using notmuch-show-insert-bodypart
instead of calling notmuch-mm-display-part-inline directly to render
the quoted parts as they are rendered in show view.

We use a temp buffer to not leak text properties from the show
renderer into the reply. This way we also don't need to worry about
narrowing or point placement. Credits to Mark Walters
<markwalters1009@gmail.com> and Austin Clements <amdragon@MIT.EDU> for
getting this part straight.

The notable change is that replies to text/calendar parts quote the
pretty printed output of icalendar-import-buffer rather than the ugly
raw vcalendar.

1 files changed, 13 insertions, 5 deletions

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 2896aae8..904b98e1 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -844,7 +844,11 @@ message at DEPTH in the current thread."
 (defun notmuch-show-insert-bodypart (msg part depth &optional hide)
   "Insert the body part PART at depth DEPTH in the current thread.
 
-If HIDE is non-nil then initially hide this part."
+HIDE determines whether to show or hide the part and the button
+as follows: If HIDE is nil, show the part and the button. If HIDE
+is t, hide the part initially and show the button. If HIDE is
+'no-buttons, show the part but do not add any buttons (this is
+useful for quoting in replies)."
 
   (let* ((content-type (downcase (plist-get part :content-type)))
 	 (mime-type (or (and (string= content-type "application/octet-stream")
@@ -854,15 +858,19 @@ If HIDE is non-nil then initially hide this part."
 			content-type))
 	 (nth (plist-get part :id))
 	 (beg (point))
-	 ;; We omit the part button for the first (or only) part if this is text/plain.
-	 (button (unless (and (string= mime-type "text/plain") (<= nth 1))
+	 ;; Hide the part initially if HIDE is t.
+	 (show-part (not (equal hide t)))
+	 ;; We omit the part button for the first (or only) part if
+	 ;; this is text/plain, or HIDE is 'no-buttons.
+	 (button (unless (or (equal hide 'no-buttons)
+			     (and (string= mime-type "text/plain") (<= nth 1)))
 		   (notmuch-show-insert-part-header nth mime-type content-type (plist-get part :filename))))
 	 (content-beg (point)))
 
     ;; Store the computed mime-type for later use (e.g. by attachment handlers).
     (plist-put part :computed-type mime-type)
 
-    (if (not hide)
+    (if show-part
         (notmuch-show-insert-bodypart-internal msg part mime-type nth depth button)
       (button-put button :notmuch-lazy-part
                   (list msg part mime-type nth depth button)))
@@ -875,7 +883,7 @@ If HIDE is non-nil then initially hide this part."
       (insert "\n"))
     ;; We do not create the overlay for hidden (lazy) parts until
     ;; they are inserted.
-    (if (not hide)
+    (if show-part
 	(notmuch-show-create-part-overlays button content-beg (point))
       (save-excursion
 	(notmuch-show-toggle-part-invisibility button)))