;; very end of the heading, before the newline, so text inserted at FROM
;; belongs to the heading rather than to the entry.
(let ((o (make-overlay from to nil 'front-advance)))
+ (overlay-put o 'evaporate t)
(overlay-put o 'invisible 'outline)
(overlay-put o 'isearch-open-invisible
(or outline-isearch-open-invisible-function