bug#22404: 25.1.50; Forcing `window-scroll-functions` to run.

[Eli Zaretskii]

> Date:  Tue, 19 Jan 2016 12:35:38 -0800
> From:  Keith David Bershatsky <esq@lawlist.com>
> Cc:  22404@debbugs.gnu.org
> 
> Explicitly calling `set-window-start` doesn't appear to trigger the WSF based 
> on the following test -- e.g., moving around the window without scrolling 
> doesn't yield any messages.
> 
> (setq scroll-conservatively 101)
> 
> (defvar pch-test-var nil)
> 
> (defun pch-fn ()
>   (set-window-start (selected-window) (window-start (selected-window)) 
> 'noforce))

Sorry, I was mistaken: you need to call set-window-start with its 3rd
argument omitted or nil.  Does that solve your problem?