bug#17453: Isearch doesn't work properly with Follow Mode.

[Alan Mackenzie]

On Mon, Nov 02, 2015 at 07:49:43PM +0200, Eli Zaretskii wrote:
> > Date: Mon, 2 Nov 2015 16:09:17 +0000
> > Cc: bruce.connor.am@gmail.com, juri@linkov.net, 17453@debbugs.gnu.org,
> >   monnier@iro.umontreal.ca
> > From: Alan Mackenzie <acm@muc.de>

> > > If this means that sit*-for does something other than redisplay and
> > > wait, like switch to another window, I'd really suggest to rethink
> > > that.  It is entirely counter-intuitive to have a sit-for family of
> > > functions do anything other than some kind of redisplay and some kind
> > > of waiting.

> > sit*-for's synchronising windows, switching to the appropriate window,
> > etc., is conceptually an extension of redisplay's scrolling to get point
> > on screen.

> No, redisplay doesn't necessarily scroll.  It does so only if needed.
> So sit-for should not be thought as a way to scroll the window, even
> if sometimes it does.

Redisplay scrolls sometimes, and it moves point sometimes.  But it does
those things only when needed for the actual display.  Similarly the
sit*-for, invoking display would do other things strictly necessary for
successful redisplay.  That sometimes would include resynchronising the
windows, for example.

> > But I think sit*-for could well be not needed here, anyway.

> That's okay, but my point is: please do not add to established
> functions code that does on behalf of Follow mode something that
> conceptually doesn't belong to those functions.  OK?

Fine!

-- 
Alan Mackenzie (Nuremberg, Germany).