Update ActionViewHelper to be compatible with Rails 2.2

CHANGELOG

@@ -1,5 +1,6 @@
 = ActiveMerchant CHANGELOG
 
+* Make ActionViewHelper compatible with changes to concat method in ActionPack [cody]
 * Remove PayPal and Payflow Name-Value gateways. PayPal is no longer terminating the Payflow XML API. [cody]
 * Don't directly use the inflector in the action view helper [cody]
 * Work around Rails Inflector change [cody]

lib/active_merchant/billing/integrations/action_view_helper.rb

@@ -39,12 +39,16 @@ module ActionViewHelper
         #    <% service.cancel_return_url 'http://mystore.com' %>
         #  <% end %>
         #
-        def payment_service_for(order, account, options = {}, &proc)
+        def payment_service_for(order, account, options = {}, &proc)          
           raise ArgumentError, "Missing block" unless block_given?
 
           integration_module = ActiveMerchant::Billing::Integrations.const_get(options.delete(:service).to_s.classify)
 
-          concat(form_tag(integration_module.service_url, options.delete(:html) || {}), proc.binding)
+          if ignore_binding?
+            concat(form_tag(integration_module.service_url, options.delete(:html) || {}))
+          else
+            concat(form_tag(integration_module.service_url, options.delete(:html) || {}), proc.binding)
+          end
           result = "\n"
 
           service_class = integration_module.const_get('Helper')
@@ -57,7 +61,17 @@ def payment_service_for(order, account, options = {}, &proc)
 
           result << "\n"
           result << '</form>' 
-          concat(result, proc.binding)
+
+          if ignore_binding?
+            concat(result)
+          else
+            concat(result, proc.binding)
+          end
+        end
+
+        private
+        def ignore_binding?
+          ActionPack::VERSION::MAJOR >= 2 && ActionPack::VERSION::MINOR >= 2
         end
       end
     end

test/unit/integrations/action_view_helper_test.rb

@@ -8,6 +8,8 @@ class ActionViewHelperTest < Test::Unit::TestCase
   include ActionView::Helpers::TagHelper
   include ActionView::Helpers::TextHelper
 
+  attr_accessor :output_buffer
+
   def setup
     @controller = Class.new do
       attr_reader :url_for_options
@@ -16,6 +18,7 @@ def url_for(options, *parameters_for_method_reference)
       end      
     end
     @controller = @controller.new
+    @output_buffer = ''
   end