bug#64759: Broken faces

[Juri Linkov]

>> It seems adding non-empty definitions in bug#64655
>> were intended to workaround a bug in cus-edit.el,
>> not to fix it.
>
> I don't think it's a bug.  Why is it a bug to tell the user that the
> face has no information to show as the current definition?

How this is different from a variable that has a nil value?
The Customization UI can handle it.

> Moreover, what does it mean to have nil there in defface?  The
> meaning of nil is not documented anywhere that I could see, so what
> did the authors of such code expect it to produce?

Why not nil?  Every variable supports a nil value.  Why can't faces
do the same?