Make current_url? work with a HEAD method

ActionDispatch::Head was removed in favor of Rack::Head. But Rack::Head
does not convert GET requests to HEAD requests so we need to do
checking for HEAD requests ourselves.

actionpack/lib/action_view/helpers/url_helper.rb

@@ -514,7 +514,7 @@ def current_page?(options)
                 "in a #request method"
         end
 
-        return false unless request.get?
+        return false unless request.get? || request.head?
 
         url_string = url_for(options)
 

actionpack/test/template/url_helper_test.rb

@@ -437,6 +437,12 @@ def request_for_url(url, opts = {})
     ActionDispatch::Request.new(env)
   end
 
+  def test_current_page_with_http_head_method
+    @request = request_for_url("/", :method => :head)
+    assert current_page?(url_hash)
+    assert current_page?("http://www.example.com/")
+  end
+
   def test_current_page_with_simple_url
     @request = request_for_url("/")
     assert current_page?(url_hash)