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

[Artur Malabarba]

>> I also changed it to use (follow-all-followers).
>
> That's unwanted.  ;-)  Isearch should not be using internal Follow Mode
> functions.  Some more abstraction would be needed.

That function goes in follow.el. ;-)

> Lazy highlighting searches for matches on the current window.  It must
> be extended to search for matches on the Follow Mode group of windows.
> For that, it needs the details of the "window*-start" and "window*-end".

Yes, you're right, I see that now. This might still be solvable via
setting isearch-search-fun-function, I'll need to think on that for a
moment.
I see nothing wrong with the window*-start/end functionality you
suggest, but if we can solve this problem via configuration points
that are already provided (like isearch-search-fun-function) then all
the better.

>> >  One way or another, isearch MUST work with the
>> > window boundaries of the entire Follow Mode group.
>
>> Maybe I missed part of the issue. I thought you wanted Isearch to
>> switch to another window if that window contains the next match
>> (instead of scrolling the current window). For that, you only need
>> pos-visible-in-window-p, you don't need to mess with boundaries.
>
> What is causing the unwanted scrolling rather than moving to the next
> window, is the form "(sit-for 0)" near the start of
> isearch-lazy-highlight-new-loop.

I think the patch I provided switches to the second (or third or
whatever) window before that sit-for runs. So I believe it solves this
problem.