(shell-mode): Use (ring-empty-p rather than (zerop (ring-length.

diff --git a/lisp/shell.el b/lisp/shell.el
index c93cc77b673ef295864e948bb5da22e02dde15c3..ec52a2f3624cbb5004f78fb18bca6c563eb67bfa 100644 (file)
--- a/lisp/shell.el
+++ b/lisp/shell.el
@@ -415,7 +415,7 @@ buffer."
   (make-local-variable 'list-buffers-directory)
   (setq list-buffers-directory (expand-file-name default-directory))
   ;; shell-dependent assignments.
-  (when (zerop (ring-length comint-input-ring))
+  (when (ring-empty-p comint-input-ring)
     (let ((shell (file-name-nondirectory (car
                   (process-command (get-buffer-process (current-buffer)))))))
       (setq comint-input-ring-file-name