bug#5129: 23.1.50; adding font-lock-keywords for face highlight

["Roland Winkler" <Roland.Winkler@physik.uni-erlangen.de>]

The highlight face is somehow treated special in an odd way:

If I eval the following in a buffer it will highlight all occurences
of "foo" as expected:

  (font-lock-add-keywords nil '(("foo" . font-lock-constant-face)))

Yet when I do instead

  (font-lock-add-keywords nil '(("foo" . highlight)))

it gives me the message (in the *Messages* buffer)

  Invalid face reference: 0

When I put point at the position of the string "foo" and evaluate

  (get-text-property (point) 'face)

this gives me

  (0 highlight)

which probably explains the "invalid face reference" error.
Why is the face `0' added?


In GNU Emacs 23.1.50.1 (i686-pc-linux-gnu, GTK+ Version 2.14.4)
 of 2009-12-04 on regnitz
Windowing system distributor `The X.Org Foundation', version 11.0.10502000

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: C
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: en_GB.utf8
  value of $LANG: en_US.ISO-8859-15
  value of $XMODIFIERS: nil
  locale-coding-system: iso-latin-9-unix
  default enable-multibyte-characters: t