* lisp/vc/add-log.el (find-change-log): Use locate-dominating-file.

diff --git a/lisp/vc/add-log.el b/lisp/vc/add-log.el
index 45e863340a56dd078b7482dbeb205fd763892c53..d1a1ba057ef59f7ff905c34c72a8a9ff3195b886 100644 (file)
--- a/lisp/vc/add-log.el
+++ b/lisp/vc/add-log.el
@@ -724,24 +724,18 @@ Optional arg BUFFER-FILE overrides `buffer-file-name'."
          ;; for several related directories.
          (setq file-name (file-chase-links file-name))
          (setq file-name (expand-file-name file-name))
-         ;; Move up in the dir hierarchy till we find a change log file.
-         (let ((file1 file-name)
-               parent-dir)
-           (while (and (not (or (get-file-buffer file1) (file-exists-p file1)))
-                       (progn (setq parent-dir
-                                    (file-name-directory
-                                     (directory-file-name
-                                      (file-name-directory file1))))
-                              ;; Give up if we are already at the root dir.
-                              (not (string= (file-name-directory file1)
-                                            parent-dir))))
-             ;; Move up to the parent dir and try again.
-             (setq file1 (expand-file-name
-                          (file-name-nondirectory (change-log-name))
-                          parent-dir)))
-           ;; If we found a change log in a parent, use that.
-           (if (or (get-file-buffer file1) (file-exists-p file1))
-               (setq file-name file1)))))
+         (let* ((cbase (file-name-nondirectory (change-log-name)))
+                (root
+                 ;; TODO stopping at VCS root dir (if present) is appropriate
+                 ;; for Emacs these days (we used to have per-directory
+                 ;; ChangeLogs), and probably most others too.
+                 ;; But it could be optional behavior.
+                 (locate-dominating-file
+                  file-name
+                  (lambda (dir)
+                    (let ((clog (expand-file-name cbase dir)))
+                      (or (get-file-buffer clog) (file-exists-p clog)))))))
+           (if root (setq file-name (expand-file-name cbase root))))))
     ;; Make a local variable in this buffer so we needn't search again.
     (set (make-local-variable 'change-log-default-name) file-name))
   file-name)