(copyright-at-end-flag): New option.

(copyright-limit): Respect copyright-at-end-flag.
(copyright-re-search, copyright-start-point)
(copyright-offset-too-large-p): New functions.
(copyright-update-year): Use copyright-re-search.
(copyright-update, copyright-fix-years): Use copyright-start-point,
and copyright-re-search.
(copyright): Use copyright-offset-too-large-p.

1 files changed, 42 insertions, 13 deletions

diff --git a/lisp/emacs-lisp/copyright.el b/lisp/emacs-lisp/copyright.el
index 910ac9eaa23..5ab50847f8c 100644
--- a/lisp/emacs-lisp/copyright.el
+++ b/lisp/emacs-lisp/copyright.el
@@ -43,6 +43,13 @@ A value of nil means to search whole buffer."
   :type '(choice (integer :tag "Limit")
                  (const :tag "No limit")))
 
+(defcustom copyright-at-end-flag nil
+  "Non-nil means to search backwards from the end of the buffer for copyright.
+This is useful for ChangeLogs."
+  :group 'copyright
+  :type 'boolean
+  :version "23.1")
+
 (defcustom copyright-regexp
  "\\(©\\|@copyright{}\\|[Cc]opyright\\s *:?\\s *\\(?:(C)\\)?\
 \\|[Cc]opyright\\s *:?\\s *©\\)\
@@ -89,18 +96,40 @@ When this is `function', only ask when called non-interactively."
   "String representing the current year.")
 
 (defsubst copyright-limit ()            ; re-search-forward BOUND
-  (and copyright-limit (+ (point) copyright-limit)))
+  (and copyright-limit
+       (if copyright-at-end-flag
+           (- (point) copyright-limit)
+         (+ (point) copyright-limit))))
+
+(defun copyright-re-search (regexp &optional bound noerror count)
+  "Re-search forward or backward depending on `copyright-at-end-flag'."
+  (if copyright-at-end-flag
+      (re-search-backward regexp bound noerror count)
+    (re-search-forward regexp bound noerror count)))
+
+(defun copyright-start-point ()
+  "Return point-min or point-max, depending on `copyright-at-end-flag'."
+  (if copyright-at-end-flag
+      (point-max)
+    (point-min)))
+
+(defun copyright-offset-too-large-p ()
+  "Return non-nil if point is too far from the edge of the buffer."
+  (when copyright-limit
+    (if copyright-at-end-flag
+        (< (point) (- (point-max) copyright-limit))
+      (> (point) (+ (point-min) copyright-limit)))))
 
 (defun copyright-update-year (replace noquery)
   (when
       (condition-case err
           ;; (1) Need the extra \\( \\) around copyright-regexp because we
           ;; goto (match-end 1) below. See note (2) below.
-          (re-search-forward (concat "\\(" copyright-regexp
-                                     "\\)\\([ \t]*\n\\)?.*\\(?:"
-                                     copyright-names-regexp "\\)")
-                             (copyright-limit)
-                             t)
+          (copyright-re-search (concat "\\(" copyright-regexp
+                                       "\\)\\([ \t]*\n\\)?.*\\(?:"
+                                       copyright-names-regexp "\\)")
+                               (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.
@@ -176,13 +205,13 @@ interactively."
       (save-excursion
         (save-restriction
           (widen)
-          (goto-char (point-min))
+          (goto-char (copyright-start-point))
           (copyright-update-year arg noquery)
-          (goto-char (point-min))
+          (goto-char (copyright-start-point))
           (and copyright-current-gpl-version
                ;; match the GPL version comment in .el files, including the
                ;; bilingual Esperanto one in two-column, and in texinfo.tex
-               (re-search-forward
+               (copyright-re-search
                 "\\(the Free Software Foundation;\
  either \\|; a\\^u eldono \\([0-9]+\\)a, ? a\\^u (la\\^u via     \\)\
 version \\([0-9]+\\), or (at"
@@ -210,8 +239,8 @@ version \\([0-9]+\\), or (at"
 Uses heuristic: year >= 50 means 19xx, < 50 means 20xx."
   (interactive)
   (widen)
-  (goto-char (point-min))
-  (if (re-search-forward copyright-regexp (copyright-limit) t)
+  (goto-char (copyright-start-point))
+  (if (copyright-re-search copyright-regexp (copyright-limit) t)
       (let ((s (match-beginning 2))
             (e (copy-marker (1+ (match-end 2))))
             (p (make-marker))
@@ -235,7 +264,7 @@ Uses heuristic: year >= 50 means 19xx, < 50 means 20xx."
           ;; Don't mess up whitespace after the years.
           (skip-chars-backward " \t")
           (save-restriction
-            (narrow-to-region (point-min) (point))
+            (narrow-to-region (copyright-start-point) (point))
             (let ((fill-prefix "     "))
               (fill-region s last))))
         (set-marker e nil)
@@ -251,7 +280,7 @@ Uses heuristic: year >= 50 means 19xx, < 50 means 20xx."
   "Copyright (C) " `(substring (current-time-string) -4) " by "
   (or (getenv "ORGANIZATION")
       str)
-  '(if (and copyright-limit (> (point) (+ (point-min) copyright-limit)))
+  '(if (copyright-offset-too-large-p)
        (message "Copyright extends beyond `copyright-limit' and won't be updated automatically."))
   comment-end \n)