Make polymorphic_url compact given array [#1317 state:committed]

Signed-off-by: David Heinemeier Hansson <david@loudthinking.com>

actionpack/CHANGELOG

@@ -1,5 +1,7 @@
 *2.2.1 [RC2 or 2.2 final]*
 
+* Fixed that polymorphic_url should compact given array #1317 [hiroshi]
+
 * Fixed the sanitize helper to avoid double escaping already properly escaped entities #683 [antonmos/Ryan McGeary]
 
 * Fixed that FormTagHelper generated illegal html if name contained square brackets #1238 [Vladimir Dobriakov]

actionpack/lib/action_controller/polymorphic_routes.rb

@@ -73,7 +73,7 @@ module ActionController
     #
     def polymorphic_url(record_or_hash_or_array, options = {})
       if record_or_hash_or_array.kind_of?(Array)
-        record_or_hash_or_array = record_or_hash_or_array.dup
+        record_or_hash_or_array = record_or_hash_or_array.compact
       end
 
       record    = extract_record(record_or_hash_or_array)

actionpack/test/controller/polymorphic_routes_test.rb

@@ -169,6 +169,17 @@ uses_mocha 'polymorphic URL helpers' do
       polymorphic_url([@article, :response, @tag], :format => :pdf)
     end
 
+    def test_nesting_with_array_containing_nil
+      expects(:article_response_url).with(@article)
+      polymorphic_url([@article, nil, :response])
+    end
+
+    def test_with_array_containing_single_object
+      @article.save
+      expects(:article_url).with(@article)
+      polymorphic_url([nil, @article])
+    end
+
     # TODO: Needs to be updated to correctly know about whether the object is in a hash or not
     def xtest_with_hash
       expects(:article_url).with(@article)