autorevert: Use defvar-local for the -mode variables

* lisp/autorevert.el (auto-revert-mode, auto-revert-tail-mode):
Use defvar-local not defvar.  New comment explaining why these
duplicate definitions of the variables are present.

1 files changed, 6 insertions, 2 deletions

diff --git a/lisp/autorevert.el b/lisp/autorevert.el
index ccedaa759cb..3bb40c13b4d 100644
--- a/lisp/autorevert.el
+++ b/lisp/autorevert.el
@@ -126,12 +126,16 @@ Global Auto-Revert Mode does so in all buffers."
 
 ;; Variables:
 
-(defvar auto-revert-mode nil
+;; These two variables are defined here in addition to within the
+;; `define-minor-mode' forms below because the modes are mutually
+;; self-referential.
+
+(defvar-local auto-revert-mode nil
   "Non-nil when Auto-Revert Mode is active.
 Never set this variable directly, use the command `auto-revert-mode' instead.")
 (put 'auto-revert-mode 'permanent-local t)
 
-(defvar auto-revert-tail-mode nil
+(defvar-local auto-revert-tail-mode nil
   "Non-nil when Auto-Revert Tail Mode is active.
 Never set this variable directly, use the command
 `auto-revert-tail-mode' instead.")