On Thu, Jun 13, 2013 at 3:18 PM, Stefan Monnier <monnier@iro.umontreal.ca>wrote:

> >> !        (let* ((cur-ovs (overlays-in (point) (1+ (point))))
> >> !               (thumb-ov (car (cl-remove-if-not
> >> !                               (lambda (ov) (overlay-get ov
> 'thumb-file))
> >> !                               cur-ovs))))
> >> !          (if thumb-ov
> >> !              (delete-overlay thumb-ov)
>
> BTW, now that I actually look at the code, I twonder why it doesn't use
> remove-overlays.
>
>
>         Stefan
>

It's a toggler. It will remove the overlay if present, or create one. And
remove-overlays always returns nil.

Evgeni