(backup-buffer-copy): If MODES is nil, don't set modes.

diff --git a/lisp/files.el b/lisp/files.el
index ce4d67d33e432d2e0cf9a3e2341ddcb2e1e1effd..4983b1287e8e633639355362c9ea18e5ae6c4aea 100644 (file)
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -2552,7 +2552,8 @@ BACKUPNAME is the backup file name, which is the old file renamed."
              (not (file-writable-p to-name)))
         (delete-file to-name))
      (copy-file from-name to-name t t)))
-  (set-file-modes to-name (logand modes #o1777)))
+  (and modes
+       (set-file-modes to-name (logand modes #o1777))))
 
 (defun file-name-sans-versions (name &optional keep-backup-version)
   "Return file NAME sans backup versions or strings.