RecordNotFound errors now trigger 404s

Exceptions that raise during view rendering do not trigger ActionDispatch's exception handler.

app/controllers/posts_controller.rb

@@ -1,4 +1,8 @@
 class PostsController < ApplicationController
+  def show
+    resource
+  end
+
   def feed
     max_age = 4.hours
     response.headers['Cache-Control'] = 'public, max-age=' + max_age.to_i.to_s

spec/acceptance/posts_spec.rb

@@ -136,4 +136,11 @@
     end
   end
 
+  context 'Posts#show with invalid slug' do
+    it 'should raise an not found exception' do
+      lambda do
+        visit post_path('2011/05/01/invalid')
+      end.should raise_error(ActiveRecord::RecordNotFound)
+    end
+  end
 end