bug#22324: 25.0.50; completion-category-defaults style doesn't override completion-styles (gets prepended instead)

[Eli Zaretskii]

> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Thu, 07 Jan 2016 23:27:23 +0300
> 
> As mentioned in
> http://lists.gnu.org/archive/html/emacs-devel/2016-01/msg00445.html,
> the docstring of completion-category-defaults, as well as its manual
> documentation do not describe its behavior accurately.
> 
> (See what `completion--styles' does.)

Would adding `partial-completion' to the list there fix this problem?
Or is there anything else that needs to be done?

Thanks.