Warn about :reverse-video in defface

This attribute keyword has been non-working in defface for 14 years,
thus warning about it is both safe and decent.

* lisp/emacs-lisp/bytecomp.el (bytecomp--check-cus-face-spec):
Warn and suggest :inverse-video to be used instead.
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-test-defface-spec):
Add a test case.
* etc/NEWS: Notify the user.

1 files changed, 5 insertions, 2 deletions

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 1c84fe0804b..47df26f01d6 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -5396,15 +5396,18 @@ FORM is used to provide location, `bytecomp--cus-function' and
                             :underline :overline :strike-through :box
                             :inverse-video :stipple :font
                             ;; FIXME: obsolete keywords, warn about them too?
-                            ;; `:reverse-video' is very rare.
                             :bold           ; :bold t   = :weight bold
                             :italic         ; :italic t = :slant italic
-                            :reverse-video  ; alias for :inverse-video
                             ))
               (when (eq (car-safe val) 'quote)
                 (bytecomp--cus-warn
                  (list val atts sp spec)
                  "Value for face attribute `%s' should not be quoted" attr)))
+             ((eq attr :reverse-video)
+              (bytecomp--cus-warn
+               (list atts sp spec)
+               (concat "Face attribute `:reverse-video' is obsolete;"
+                       " use `:inverse-video' instead")))
              (t
               (bytecomp--cus-warn
                (list atts sp spec)