Re: [Emacs-trunk-diffs] Changes to emacs/etc/NEWS

[Richard Stallman <rms@gnu.org>]

    ** An unconditional face specification in defface (one where the DISPLAY part
    is just t) applies to all cases and does not override subsequent entries.

This feature does not seem cleanly designed to me.  The first slot in
the spec is supposed to be a condition, and t as a condition has a
very clear meaning in Lisp.  To use t for any other meaning seems very
wrong.

It also seems that this change wasn't fully implemented,
because the code in cus-edit.el that interprets face specs
doesn't know about it.

I think we should replace this with a clean feature before
releasing it.  Here's one idea for a clean feature:

t as the condition means "or else", as it used to, as
people would expect.  nil as the condition means "default",
attributes to be shared by all the conditions.

It should not be very hard to implement this in faces.el instead of
the current code.  However, it needs to be implemented also in
cus-edit.el, which is harder, and in the Lisp manual.
Also, someone needs to check all 500-odd deffaces, but that
probably needs to be done anyway, and most of them will take
only a few seconds to see there's no issue.

Can you or someone please undertake to do this?