+(defun notmuch-show-open-or-close-all ()
+ "Set the visibility all of the messages in the current thread.
+By default make all of the messages visible. With a prefix
+argument, hide all of the messages."
+ (interactive)
+ (save-excursion
+ (goto-char (point-min))
+ (loop do (notmuch-show-message-visible (notmuch-show-get-message-properties)
+ (not current-prefix-arg))
+ until (not (notmuch-show-goto-message-next))))
+ (force-window-update))
+