hi-lock-mode doesn't work with emacs -Q.

[Alan Mackenzie]

Hi, Stefan!

Start emacs -Q.  (Emacs 22.1, of course).  Visit a new file with:

    C-x C-f foo.txt

.  Type this:

    This file is foo.txt.

.  Enable hi-lock-mode and make "foo" a highlightable pattern:

    M-x hi-lock-mode
    C-x w h foo<CR><CR>    ; accept the default hi-yellow face.

.  This highlights the "foo" yellow, as expected.  At the end of the
line, type:

    foo

.  This new "foo" doesn't get highlighted.  It should be.

#########################################################################

Partial diagnosis:
(i) The bug happens even when global-hi-lock-mode is enabled.
(ii) after-change-functions is nil.  It ought to be
  (jit-lock-after-change t).
(iii) font-lock-mode is t.

How can font-lock-mode be t, whilst at the same time there is no
after-change function?  Is this some optimisation in Font Lock mode
that only sets after-change-functions when font-lock-keywords is
non-nil?

hi-lock.el doesn't seem to be violating Font Lock's proper calling
conventions in any way.

Stefan, I think you're the best person to fix this.

-- 
Alan Mackenzie (Ittersbach, Germany).