Re: Adding missing copyright years

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> >       (add-hook 'before-save-hook 'copyright-update)
>> 
>> This is not a problem since you are asked whether you want to update the
>> copyright.

> Indeed; I use it, and I don't think it's dangerous in the way Richard
> suggested (it always leaves the final decision to the user).

> However, I can see why some people would not like to use it in its
> current form -- it's generally quite stupid, and often mistakenly
> thinks the copyright may need updating when the current copyright line
> is actually up-to-date.  So it tends to ask you whether you want to
> update the copyright far more often than it should (for example, it
> doesn't understand wrapped copyright lines, and gets confused if there
> are multiple copyrights).

I haven't seen the problem with wrapped lines, but as far as multiple
copyrights goes I use a the local hack below where I can specify a regexp
for the copyrights that I'm willing to change (e.g. I don't want my edits to
add a year to the copyright of someone else, right?).

I've then set copyright-names-regexp to "Monnier\\|Free Software".
This way when I edit a file with multiple copyrights, only the relevant line
is checked/updated.  I've only written it recently (after the feature
freeze), which is why I haven't tried to install it.


        Stefan


--- orig/lisp/emacs-lisp/copyright.el
+++ mod/lisp/emacs-lisp/copyright.el
@@ -54,6 +54,13 @@
   :group 'copyright
   :type 'regexp)
 
+(defcustom copyright-names-regexp ""
+  "Regexp matching the names which correspond to the user.
+Only copyright lines where the name matches this regexp will be updated.
+This allows you to avoid adding yars to a copyright notice belonging to
+someone else or to a group for which you do not work."
+  :type 'regexp)
+
 (defcustom copyright-years-regexp
  "\\(\\s *\\)\\([1-9]\\([-0-9, ';/*%#\n\t]\\|\\s<\\|\\s>\\)*[0-9]+\\)"
   "*Match additional copyright notice years.
@@ -83,7 +90,17 @@
   "String representing the current year.")
 
 (defun copyright-update-year (replace noquery)
-  (when (re-search-forward copyright-regexp (+ (point) copyright-limit) t)
+  (when
+      (condition-case err
+	  (re-search-forward (concat "\\(" copyright-regexp
+				     "\\)\\([ \t]*\n\\)?.*\\(?:"
+				     copyright-names-regexp "\\)")
+			     (+ (point) copyright-limit) t)
+	;; In case the regexp is rejected.  This is useful because
+	;; copyright-update is typically called from before-save-hook where
+	;; such an error is very inconvenient for the user.
+	(error (message "Can't update copyright: %s" err) nil))
+    (goto-char (match-end 1))
     ;; If the years are continued onto multiple lined
     ;; that are marked as comments, skip to the end of the years anyway.
     (while (save-excursion
@@ -94,7 +111,7 @@
 		  (save-match-data
 		    (forward-line 1)
 		    (and (looking-at comment-start-skip)
-			 (goto-char (match-end 0))))
+			 (goto-char (match-end 1))))
 		  (save-match-data
 		    (looking-at copyright-years-regexp))))
       (forward-line 1)
@@ -103,7 +120,7 @@
 
     ;; Note that `current-time-string' isn't locale-sensitive.
     (setq copyright-current-year (substring (current-time-string) -4))
-    (unless (string= (buffer-substring (- (match-end 2) 2) (match-end 2))
+    (unless (string= (buffer-substring (- (match-end 3) 2) (match-end 3))
 		     (substring copyright-current-year -2))
       (if (or noquery
 	      (y-or-n-p (if replace