(file-chase-links): New function.

(backup-buffer): Use file-chase-links.

diff --git a/lisp/files.el b/lisp/files.el
index d0df89b29628c0d4cd31971011a5a075872ae991..44aea8525edda94fffa93cdfcbffbde24b514cfc 100644 (file)
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -343,6 +343,17 @@ containing it, until no links are left at any level."
          ;; No, we are done!
          filename)))))
 
+(defun file-chase-links (filename)
+  "Chase links in FILENAME until a name that is not a link.
+Does not examine containing directories for links,
+unlike `file-truename'."
+  (let (tem (count 100) (newname filename))
+    (while (setq tem (file-symlink-p newname))
+      (if (= count 0)
+         (error "Apparent cycle of symbolic links for %s" filename))
+      (setq newname (expand-file-name tem (file-name-directory newname)))
+      (setq count (1- count)))
+    newname))
 \f
 (defun switch-to-buffer-other-window (buffer)
   "Select buffer BUFFER in another window."
@@ -1092,12 +1103,7 @@ the modes of the new file to agree with the old modes."
            backup-info backupname targets setmodes)
        ;; If specified name is a symbolic link, chase it to the target.
        ;; Thus we make the backups in the directory where the real file is.
-       (while (let ((tem (file-symlink-p real-file-name)))
-                (if tem
-                    (setq real-file-name
-                          (expand-file-name tem
-                                            (file-name-directory real-file-name))))
-                tem))
+       (setq real-file-name (file-chase-links real-file-name))
        (setq backup-info (find-backup-file-name real-file-name)
              backupname (car backup-info)
              targets (cdr backup-info))