Daiki Ueno <ueno(a)unixuser.org> writes:
The immediate cause is that set-text-properties calls for the
[0, 0] range of the current buffer in browse-url-url-at-point
when there is no URL text around point.
(defun browse-url-url-at-point () (let ((url (thing-at-point
'url))) (set-text-properties 0 (length url) nil url) url))
GNU Emacs's set-text-properties, however, doesn't fail in the
same situation. I don't know which is a better place to fix the
symptoms, fsf-compat/text-props.el or browse-url.el.
IMHO the better solution is to make `set-text-properties'
consistent with Emacs. I couldn't find fsf-compat/text-props.el
though, so I'll leave it to someone else to explore.