bug#9153: 23.3; browse-url too greedy

[Chong Yidong]

Lars Magne Ingebrigtsen <larsi@gnus.org> writes:

> Recognising URLs in free text is all heuristics.
>
> URLs like this "http://emacs.org)" are exceedingly rare, while
> "http://wikipedia.org/thing(something)" are not uncommon.  I fail to
> see how catering to the more common case is akin to "generating bugs".

I've committed a change to thingatpt.el to fix this.