bug#37774: 27.0.50; new :extend attribute broke visuals of all themes and other packages

[Dmitry Gutov]

On 17.10.2019 20:23, Eli Zaretskii wrote:
> But there's a more general claim in this bug report: that the change
> will screw many unbundled packages out there; if that is true,
> changing some faces in core is not a solution.

Yeah, so: what's the plan for Magit?

Will the new version of it have to

(if <emacs version is...>
    (defface ...)
  (defface ...)

?

Essentially copying the definition of each affected face?

I'm not sure it can use set-face-attribute here, because if this 
attribute is allowed to be overridden by a theme, packages should 
respect that.