Avoid errors in Auto Revert mode

* lisp/autorevert.el (auto-revert-buffers): Cancel
auto-revert-timer only if it is non-nil.  This avoids errors
on first invocation of Auto-Revert mode.

diff --git a/lisp/autorevert.el b/lisp/autorevert.el
index d1b8f94a8e288cebcc0137d02a0ccbafc281f530..242344fe9d1d3c476b2c02558ec70a25de08801f 100644 (file)
--- a/lisp/autorevert.el
+++ b/lisp/autorevert.el
@@ -813,7 +813,8 @@ the timer when no buffers need to be checked."
       ;; Check if we should cancel the timer.
       (when (and (not global-auto-revert-mode)
                 (null auto-revert-buffer-list))
-       (cancel-timer auto-revert-timer)
+        (if (timerp auto-revert-timer)
+            (cancel-timer auto-revert-timer))
        (setq auto-revert-timer nil)))))