(font-lock-keywords): Fix doc for multiline matches.

(font-lock-add-keywords): Make it work even if font-lock-mode is nil,
so that it can be used more easily in <foo>-mode-hook.  Also make sure
to avoid duplicate entries.
(font-lock-update-removed-keyword-alist): Renamed `major-mode'->`mode'.
(font-lock-remove-keywords): Just as was done for `add', allow it to
work even if font-lock-mode is nil.  Also make sure we don't modify
any pre-existing list by forcing a copy-sequence.  Finally rename
`major-mode' to `mode'.
(font-lock-fontify-syntactic-anchored-keywords)
(font-lock-fontify-anchored-keywords)
(font-lock-fontify-keywords-region): Use line-end-position.
Don't make `font-lock-multiline' local (it's now done in
font-lock-set-defaults).
(font-lock-set-defaults): Make `font-lock-multiline' local.  Also
move the `font-lock-fontified' creation to inside the `unless'.

2 files changed, 60 insertions, 36 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 5948451a086..121ea011e45 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,22 @@
+2000-02-06  Stefan Monnier  <monnier@cs.yale.edu>
+
+        * font-lock.el (font-lock-keywords): Fix doc for multiline matches.
+        (font-lock-add-keywords): Make it work even if font-lock-mode is nil,
+        so that it can be used more easily in <foo>-mode-hook.  Also make sure
+        to avoid duplicate entries.
+        (font-lock-update-removed-keyword-alist): Renamed `major-mode'->`mode'.
+        (font-lock-remove-keywords): Just as was done for `add', allow it to
+        work even if font-lock-mode is nil.  Also make sure we don't modify
+        any pre-existing list by forcing a copy-sequence.  Finally rename
+        `major-mode' to `mode'.
+        (font-lock-fontify-syntactic-anchored-keywords)
+        (font-lock-fontify-anchored-keywords)
+        (font-lock-fontify-keywords-region): Use line-end-position.
+        Don't make `font-lock-multiline' local (it's now done in
+        font-lock-set-defaults).
+        (font-lock-set-defaults): Make `font-lock-multiline' local.  Also
+        move the `font-lock-fontified' creation to inside the `unless'.
+
 2000-02-06  Andrew Innes  <andrewi@gnu.org>
 
         * term/w32-win.el (x-handle-args): Comment out call to message,
diff --git a/lisp/font-lock.el b/lisp/font-lock.el
index cecc933b621..f264805f3d7 100644
--- a/lisp/font-lock.el
+++ b/lisp/font-lock.el
@@ -389,9 +389,10 @@ PRE-MATCH-FORM is evaluated, that position is used as the limit of the search.
 It is generally a bad idea to return a position greater than the end of the
 line, i.e., cause the MATCHER search to span lines.
 
-These regular expressions should not match text which spans lines.  While
-\\[font-lock-fontify-buffer] handles multi-line patterns correctly, updating
-when you edit the buffer does not, since it considers text one line at a time.
+These regular expressions can match text which spans lines, although
+it is better to avoid it if possible since updating them while editing
+text is slower, and it is not guaranteed to be always correct when using
+support modes like jit-lock or lazy-lock.
 
 This variable is set by major modes via the variable `font-lock-defaults'.
 Be careful when composing regexps for this list; a poorly written pattern can
@@ -768,11 +769,12 @@ see the variables `c-font-lock-extra-types', `c++-font-lock-extra-types',
          ;; Make sure that `font-lock-removed-keywords-alist' does not
          ;; contain the new keywords.
          (font-lock-update-removed-keyword-alist mode keywords append))
-        (font-lock-mode
-         ;; Otherwise if Font Lock mode is on, set or add the keywords now.
-         (if (eq append 'set)
-             (setq font-lock-keywords keywords)
-           (font-lock-remove-keywords mode keywords)
+        (t
+         ;; Otherwise set or add the keywords now.
+         (font-lock-set-defaults)
+         (if (eq append 'set)
+             (setq font-lock-keywords keywords)
+           (font-lock-remove-keywords nil keywords) ;to avoid duplicates
            (let ((old (if (eq (car-safe font-lock-keywords) t)
                           (cdr font-lock-keywords)
                         font-lock-keywords)))
@@ -780,9 +782,9 @@ see the variables `c-font-lock-extra-types', `c++-font-lock-extra-types',
                                           (append old keywords)
                                         (append keywords old))))))))
 
-(defun font-lock-update-removed-keyword-alist (major-mode keywords append)
+(defun font-lock-update-removed-keyword-alist (mode keywords append)
   ;; Update `font-lock-removed-keywords-alist' when adding new
-  ;; KEYWORDS to MAJOR-MODE.
+  ;; KEYWORDS to MODE.
   ;;
   ;; When font-lock is enabled first all keywords in the list
   ;; `font-lock-keywords-alist' are added, then all keywords in the
@@ -790,7 +792,7 @@ see the variables `c-font-lock-extra-types', `c++-font-lock-extra-types',
   ;; keyword was once added, removed, and then added again it must be
   ;; removed from the removed-keywords list.  Otherwise the second add
   ;; will not take effect.
-  (let ((cell (assq major-mode font-lock-removed-keywords-alist)))
+  (let ((cell (assq mode font-lock-removed-keywords-alist)))
     (if cell
         (if (eq append 'set)
             ;; A new set of keywords is defined.  Forget all about
@@ -800,7 +802,7 @@ see the variables `c-font-lock-extra-types', `c++-font-lock-extra-types',
           ;; Delete all previously removed keywords.
           (dolist (kword keywords)
             (setcdr cell (delete kword (cdr cell))))
-          ;; Delete the major-mode cell if empty.
+          ;; Delete the mode cell if empty.
           (if (null (cdr cell))
               (setq font-lock-removed-keywords-alist
                     (delq cell font-lock-removed-keywords-alist)))))))
@@ -825,16 +827,16 @@ see the variables `c-font-lock-extra-types', `c++-font-lock-extra-types',
 ;;
 ;; (II) The keywords are removed from the current buffer.
 ;;;###autoload
-(defun font-lock-remove-keywords (major-mode keywords)
-  "Remove highlighting KEYWORDS for MAJOR-MODE.
+(defun font-lock-remove-keywords (mode keywords)
+  "Remove highlighting KEYWORDS for MODE.
 
-MAJOR-MODE should be a symbol, the major mode command name, such as `c-mode'
+MODE should be a symbol, the major mode command name, such as `c-mode'
 or nil.  If nil, highlighting keywords are removed for the current buffer."
-  (dolist (keyword keywords)
-    ;; Remove one keyword at the time.
-    (cond (major-mode
-           (let ((top-cell (assq major-mode font-lock-keywords-alist)))
-             ;; If MAJOR-MODE is non-nil, remove the KEYWORD from
+  (cond (mode
+         ;; Remove one keyword at the time.
+         (dolist (keyword keywords)
+           (let ((top-cell (assq mode font-lock-keywords-alist)))
+             ;; If MODE is non-nil, remove the KEYWORD from
              ;; `font-lock-keywords-alist'.
              (when top-cell
                (dolist (keyword-list-append-pair (cdr top-cell))
@@ -859,19 +861,22 @@ or nil.  If nil, highlighting keywords are removed for the current buffer."
                    (setq font-lock-keywords-alist
                          (delq top-cell font-lock-keywords-alist))))
              ;; Remember the keyword in case it is not local.
-             (let ((cell (assq major-mode font-lock-removed-keywords-alist)))
+             (let ((cell (assq mode font-lock-removed-keywords-alist)))
                (if cell
                    (unless (member keyword (cdr cell))
                      (nconc cell (list keyword)))
-                 (push (cons major-mode (list keyword))
-                       font-lock-removed-keywords-alist)))))
-          (font-lock-mode
-           ;; Otherwise if Font Lock mode is on, remove it immediately.
-           (setq font-lock-keywords (delete keyword font-lock-keywords))
-           ;; The keywords might be compiled.
+                 (push (cons mode (list keyword))
+                       font-lock-removed-keywords-alist))))))
+        (t
+         ;; Otherwise remove it immediately.
+         (font-lock-set-defaults)
+         (setq font-lock-keywords (copy-sequence font-lock-keywords))
+         (dolist (keyword keywords)
            (setq font-lock-keywords
-                 (delete (font-lock-compile-keyword keyword)
-                         font-lock-keywords))))))
+                 (delete keyword
+                         ;; The keywords might be compiled.
+                         (delete (font-lock-compile-keyword keyword)
+                                 font-lock-keywords)))))))
 
 ;;; Global Font Lock mode.
 
@@ -1412,7 +1417,7 @@ LIMIT can be modified by the value of its PRE-MATCH-FORM."
     ;; Set LIMIT to value of PRE-MATCH-FORM or the end of line.
     (if (and (numberp pre-match-value) (> pre-match-value (point)))
         (setq limit pre-match-value)
-      (save-excursion (end-of-line) (setq limit (point))))
+      (setq limit (line-end-position)))
     (save-match-data
       ;; Find an occurrence of `matcher' before `limit'.
       (while (if (stringp matcher)
@@ -1561,14 +1566,14 @@ LIMIT can be modified by the value of its PRE-MATCH-FORM."
         (pre-match-value (eval (nth 1 keywords))))
     ;; Set LIMIT to value of PRE-MATCH-FORM or the end of line.
     (if (not (and (numberp pre-match-value) (> pre-match-value (point))))
-        (save-excursion (end-of-line) (setq limit (point)))
+        (setq limit (line-end-position))
       (setq limit pre-match-value)
       (when (and font-lock-multiline
                  (funcall (if (eq font-lock-multiline t) '>= '>)
                           pre-match-value
                           (save-excursion (forward-line 1) (point))))
         ;; this is a multiline anchored match
-        (set (make-local-variable 'font-lock-multiline) t)
+        (setq font-lock-multiline t)
         (put-text-property (point) limit 'font-lock-multiline t)))
     (save-match-data
       ;; Find an occurrence of `matcher' before `limit'.
@@ -1612,7 +1617,7 @@ START should be at the beginning of a line."
                             (save-excursion (goto-char (match-beginning 0))
                                             (forward-line 1) (point))))
           ;; this is a multiline regexp match
-          (set (make-local-variable 'font-lock-multiline) t)
+          (setq font-lock-multiline t)
           (put-text-property (match-beginning 0) (point)
                              'font-lock-multiline t))
         ;; Apply each highlight to this instance of `matcher', which may be
@@ -1690,13 +1695,13 @@ A LEVEL of nil is equal to a LEVEL of 0, a LEVEL of t is equal to
   "Set fontification defaults appropriately for this mode.
 Sets various variables using `font-lock-defaults' (or, if nil, using
 `font-lock-defaults-alist') and `font-lock-maximum-decoration'."
-  ;; Set fontification defaults.
-  (make-local-variable 'font-lock-fontified)
-  ;; Set iff not previously set.
+  ;; Set fontification defaults iff not previously set.
   (unless font-lock-set-defaults
     (set (make-local-variable 'font-lock-set-defaults)          t)
     (set (make-local-variable 'font-lock-cache-state)           nil)
     (set (make-local-variable 'font-lock-cache-position)        (make-marker))
+    (make-local-variable 'font-lock-fontified)
+    (make-local-variable 'font-lock-multiline)
     (let* ((defaults (or font-lock-defaults
                          (cdr (assq major-mode font-lock-defaults-alist))))
            (keywords