Re: [BUG] No fontification when font-lock-add-keywords is passed nil as the mode

[Francis Litterio]

Richard Stallman wrote:

> Does this fix it?  Could people who are more familiar
> with font-lock mode verify this is correct?  I have changed
> the format of a "compiled" keywords list, which might have introduced
> some bugs.

[patch omitted]

In addition to not fixing the original bug, the above patch to
font-lock.el introduced a new bug.  Eval this form to see the below
backtrace:

(progn
  (require 'font-lock)
  (defun my-dired-mode-hook ()
    (font-lock-add-keywords nil '(("^  d" 2 'highlight nil)))
    (turn-on-font-lock))
  (add-hook 'dired-mode-hook 'my-dired-mode-hook)
  (dired "/"))


Debugger entered--Lisp error: (wrong-type-argument sequencep 
dired-font-lock-keywords)
  mapcar(font-lock-compile-keyword dired-font-lock-keywords)
  (cons keywords (mapcar (quote font-lock-compile-keyword) keywords))
  (cons t (cons keywords (mapcar ... keywords)))
  (setq keywords (cons t (cons keywords ...)))
  (if (eq (car-safe keywords) t) keywords (setq keywords (cons t ...)) (if (and 
regexp ... ...) (nconc keywords ...)) keywords)
  font-lock-compile-keywords(dired-font-lock-keywords t)
  (set (make-local-variable (quote font-lock-keywords)) 
(font-lock-compile-keywords keywords t))
  (if (eq (car font-lock-keywords) t) nil (set (make-local-variable ...) 
(font-lock-compile-keywords keywords t)))
  (unless (eq (car font-lock-keywords) t) (set (make-local-variable ...) 
(font-lock-compile-keywords keywords t)))
  (let* ((defaults ...) (keywords ...) (local ...) (removed-keywords ...)) (set 
(make-local-variable ...) defaults) (when (nth 1 defaults) (set ... t)) (when 
(nth 2 defaults) (set ... t)) (when (nth 3 defaults) (set ... ...) (dolist ... 
...)) (when (nth 4 defaults) (set ... ...)) (dolist (x ...) (set ... ...)) (set 
(make-local-variable ...) (font-lock-eval-keywords keywords)) (while local 
(font-lock-add-keywords nil ... ...) (setq local ...)) (when removed-keywords 
(font-lock-remove-keywords nil removed-keywords)) (unless (eq ... t) (set ... 
...)))
  (if font-lock-set-defaults nil (set (make-local-variable ...) t) 
(make-local-variable (quote font-lock-fontified)) (make-local-variable (quote 
font-lock-multiline)) (let* (... ... ... ...) (set ... defaults) (when ... ...) 
(when ... ...) (when ... ... ...) (when ... ...) (dolist ... ...) (set ... ...) 
(while local ... ...) (when removed-keywords ...) (unless ... ...)))
  (unless font-lock-set-defaults (set (make-local-variable ...) t) 
(make-local-variable (quote font-lock-fontified)) (make-local-variable (quote 
font-lock-multiline)) (let* (... ... ... ...) (set ... defaults) (when ... ...) 
(when ... ...) (when ... ... ...) (when ... ...) (dolist ... ...) (set ... ...) 
(while local ... ...) (when removed-keywords ...) (unless ... ...)))
  font-lock-set-defaults()
  (cond (mode (let ... ...) (font-lock-update-removed-keyword-alist mode 
keywords append)) (t (font-lock-set-defaults) (let ... ... ... ...)))
  font-lock-add-keywords(nil (("^  d" 2 (quote highlight) nil)))
  my-dired-mode-hook()
  run-hooks(dired-mode-hook)
  apply(run-hooks dired-mode-hook)
  run-mode-hooks(dired-mode-hook)
  dired-mode("c:/" "-al")
  dired-internal-noselect("c:/" nil)
  dired-noselect("/" nil)
  dired("/")
  (progn (require (quote font-lock)) (defun my-dired-mode-hook nil 
(font-lock-add-keywords nil ...) (turn-on-font-lock)) (add-hook (quote 
dired-mode-hook) (quote my-dired-mode-hook)) (dired "/"))
  eval((progn (require (quote font-lock)) (defun my-dired-mode-hook nil 
(font-lock-add-keywords nil ...) (turn-on-font-lock)) (add-hook (quote 
dired-mode-hook) (quote my-dired-mode-hook)) (dired "/")))
  eval-last-sexp-1(nil)
  eval-last-sexp(nil)
  call-interactively(eval-last-sexp)