Thanks.

Yes, I had then ended up replacing all my write-file-functions add-hooks
with before-save-hook:
https://github.com/kaushalmodi/.emacs.d/commit/d89d6333f0978d7fda4af412ecaa5089812b7e26

--
Kaushal Modi
On Sep 16, 2015 9:54 PM, "Stefan Monnier" <monnier@iro.umontreal.ca> wrote:

> > I also have now started using before-save-hook instead of
> > write-file-functions where I don't care about the return values of the
> > functions added to the hook.
>
> BTW, the use of before-save-hook is not just so you don't have to care
> about the return value.  It's also because some functions on
> write-file-functions may not be run at all (if some earlier function
> returns non-nil because it took care of performing the write).
>
> So even adding a "nil" at the of your function doesn't make it right to
> add it to write-file-functions.
>
>
>         Stefan
>