Fix incomplete work from [6951] that was hidden by test stubs. Closes #6432.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6959 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/lib/action_view/helpers/form_helper.rb

@@ -155,23 +155,24 @@ module ActionView
       #   end
       #
       # If you don't need to attach a form to a model instance, then check out FormTagHelper#form_tag.
-      def form_for(record_or_name, *args, &proc)
+      def form_for(record_or_name_or_array, *args, &proc)
         raise ArgumentError, "Missing block" unless block_given?
 
         options = args.last.is_a?(Hash) ? args.pop : {}
 
-        case record_or_name
+        case record_or_name_or_array
         when String, Symbol
-          object_name = record_or_name
+          object_name = record_or_name_or_array
         when Array
-          object = record_or_name.last
+          object = record_or_name_or_array.last
           object_name = ActionController::RecordIdentifier.singular_class_name(object)
-          apply_form_for_options!(object, options, *record_or_name)
+          # apply_form_for_options!(object, options, *record_or_name_or_array)
+          apply_form_for_options!(record_or_name_or_array, options)
           args.unshift object
         else
-          object = record_or_name
+          object = record_or_name_or_array
           object_name = ActionController::RecordIdentifier.singular_class_name(object)
-          apply_form_for_options!(object, options)
+          apply_form_for_options!([ object ], options)
           args.unshift object
         end
 
@@ -180,7 +181,9 @@ module ActionView
         concat('</form>', proc.binding)
       end
 
-      def apply_form_for_options!(object, options, *nested_objects) #:nodoc:
+      def apply_form_for_options!(object_or_array, options) #:nodoc:
+        object = object_or_array.is_a?(Array) ? object_or_array.last : object_or_array
+        
         html_options =
           if object.respond_to?(:new_record?) && object.new_record?
             { :class  => dom_class(object, :new),  :id => dom_id(object), :method => :post }
@@ -190,7 +193,7 @@ module ActionView
 
         options[:html] ||= {}
         options[:html].reverse_merge!(html_options)
-        options[:url] ||= polymorphic_path(object, *nested_objects)
+        options[:url] ||= polymorphic_path(object_or_array)
       end
 
       # Creates a scope around a specific model object like form_for, but doesn't create the form tags themselves. This makes

actionpack/test/template/form_helper_test.rb

@@ -641,19 +641,27 @@ class FormHelperTest < Test::Unit::TestCase
       "/posts/#{post.id}/comments/#{comment.id}"
     end
 
-    def polymorphic_path(object, *nested_objects)
-      if nested_objects.empty?
-        if object.new_record?
-          "/posts"
-        else
-          "/posts/#{object.id}"
-        end
+    def polymorphic_path(record_or_hash_or_array)  
+      if record_or_hash_or_array.is_a?(Array)
+        record = record_or_hash_or_array.pop
+        array = record_or_hash_or_array
       else
-        if object.new_record?
+        record = record_or_hash_or_array
+        array = [ ]
+      end
+      
+      if array.size > 0
+        if record.new_record? 
           "/posts/123/comments"
         else
-          "/posts/123/comments/#{object.id}"
+          "/posts/123/comments/#{record.id}"
         end
-      end
+      else
+        if record.new_record?
+          "/posts"
+        else
+          "/posts/#{record.id}"
+        end          
+      end        
     end
 end