Added a timestamp to the captcha url. Added a set_cache buster method

to application controller to prevent the browser from caching pages.

app/controllers/application_controller.rb

@@ -159,6 +159,13 @@ def check_ssl #:nodoc:
     end
   end
 
+  # Helper method to tell the browser not to cache a page
+  def set_cache_buster
+    response.headers["Cache-Control"] = "no-cache, no-store, max-age=0, must-revalidate"
+    response.headers["Pragma"] = "no-cache"
+    response.headers["Expires"] = "Fri, 01 Jan 1990 00:00:00 GMT"
+  end
+
   # helper method to redirect a user to the access denied page
   # call from a controller method with :
   #

vendor/modules/feedback/app/controllers/feedback/captcha_controller.rb

@@ -2,6 +2,7 @@
 class Feedback::CaptchaController < ApplicationController
   def image
     @captcha = WebivaCaptcha.new self
+    set_cache_buster
     render :text => @captcha.render
   end
 end

vendor/modules/feedback/app/models/feedback_captcha.rb

@@ -52,7 +52,7 @@ def phrase
   end
 
   def url
-    "/website/feedback/captcha/image/#{self.captcha_code}"
+    "/website/feedback/captcha/image/#{self.captcha_code}?Z=#{Time.now.to_i}"
   end
 
   def partial