bug#64759: Broken faces

[Juri Linkov]

> But it seems to me that it's better to define it like this:
> (defface foo '((t nil)) "...")
> so that the face gets a face-defface-spec property.
>
> So maybe the definition for display-time-date-and-time should be changed
> to:
> (defface display-time-date-and-time
>   '((t nil))
>   "Face for `display-time-format'."
>   :group 'mode-line-faces
>   :version "30.1")
>
> instead that making it inherit from mode-line?

Thanks, I confirm that '((t nil)) solves this problem.
If a nil value can't be supported for faces, then
let's use '((t nil)).