Evaluation progress bar, fixes clojure-emacs#1197

cider-interaction.el

@@ -1715,14 +1715,19 @@ If `cider-interactive-eval-override' is a function, call it with the same
 arguments and only proceed with evaluation if it returns nil."
   (let ((form  (or form (apply #'buffer-substring bounds)))
         (start (car-safe bounds))
-        (end   (car-safe (cdr-safe bounds))))
+        (end   (car-safe (cdr-safe bounds)))
+        (eval-buffer (current-buffer)))
     (unless (and cider-interactive-eval-override
                  (functionp cider-interactive-eval-override)
                  (funcall cider-interactive-eval-override form callback bounds))
       (cider--prep-interactive-eval form)
+      (spinner-start 'progress-bar)
       (nrepl-request:eval
        form
-       (or callback (cider-interactive-eval-handler nil end))
+       (lambda (&rest args)
+           (with-current-buffer eval-buffer (spinner-stop))
+           (let ((cb (or callback (cider-interactive-eval-handler nil end))))
+             (when cb (apply cb args))))
        ;; always eval ns forms in the user namespace
        ;; otherwise trying to eval ns form for the first time will produce an error
        (if (cider-ns-form-p form) "user" (cider-current-ns))