On Sun, Sep 19 2010, Lars Magne Ingebrigtsen wrote:

> Ok.  It might not even be an issue any more -- I haven't benchmarked
> stuff like that in a decade or more.

Well, tested on 5K messages. it only takes ~2s here to manipulate the
marks with "M C" or M-5000 M-u. :-)

> Nope.  It's why Gnus uses subst-char-in-region many places where other
> solutions might be more natural.

I grepped the sources, and anyhow, all other functions using
subst-char-in-region are using predefined replacement chars, not user
defined like in gnus-summary-update-mark. So they're safe (from me :-))
and should not bug out.

-- 
Julien Danjou
// ᐰ <julien@danjou.info>   http://julien.danjou.info