* lisp/emacs-lisp/eldoc.el (eldoc-mode): Fix thinko.

* lisp/progmodes/elisp-mode.el (elisp--eldoc-last-data): Use defvar.

lisp/ChangeLog

+2014-09-27  Leo Liu  <sdl.web@gmail.com>
+
+	* progmodes/elisp-mode.el (elisp--eldoc-last-data): Use defvar.
+
+	* emacs-lisp/eldoc.el (eldoc-mode): Fix thinko.
+
 2014-09-27  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* emacs-lisp/pcase.el (pcase--split-match, pcase--app-subst-match):

lisp/emacs-lisp/eldoc.el

@@ -186,7 +186,7 @@ expression point is on."
   :group 'eldoc :lighter eldoc-minor-mode-string
   (setq eldoc-last-message nil)
   (cond
-   (eldoc-documentation-function
+   ((not eldoc-documentation-function)
     (message "There is no ElDoc support in this buffer")
     (setq eldoc-mode nil))
    (eldoc-mode

lisp/progmodes/elisp-mode.el

@@ -1009,7 +1009,7 @@ which see."
 
 ;;; ElDoc Support
 
-(defconst elisp--eldoc-last-data (make-vector 3 nil)
+(defvar elisp--eldoc-last-data (make-vector 3 nil)
   "Bookkeeping; elements are as follows:
   0 - contains the last symbol read from the buffer.
   1 - contains the string last displayed in the echo area for variables,