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

[Artur Malabarba]

2015-11-03 15:49 GMT+00:00 Eli Zaretskii <eliz@gnu.org>:
>> This is complicated.  Ideally, the Follow Mode windows should be
>> synchronised in FM's post-command-hook, not isearch's.  It is not
>> isearch's job to realign windows.  follow-post-command-hook both realigns
>> windows and choses an appropriate window to put point in.  We should let
>> it.
>
> Once again, if some code in Isearch calls the same function that is
> used in follow-post-command-hook, the above is not an issue.
> Moreover, saving some calls to the hook will make Emacs more
> responsive.

I agree with Eli and Juri on this. If there's a solution as simple as
calling a follow-mode function in isearch-post-update-hook, then this
sounds like a no-downside solution.
Of course it's not isearch's job to realign windows, but that's why
the hook exists: so that other packages can run their own functions
and do their own jobs at that point in time.