don't delete block option when indexing

lib/xapit/client/index_builder.rb

@@ -39,6 +39,7 @@ def update_document(member)
       def document_data(member)
         data = {:class => member.class.name, :id => member.id, :attributes => {}}
         attributes.each do |name, options|
+          options = options.dup # so we can remove block without changing original hash
           value = member.send(name)
           value = options.delete(:_block).call(value) if options[:_block]
           data[:attributes][name] = options.merge(:value => value)

spec/xapit/client/index_builder_spec.rb

@@ -61,6 +61,7 @@
     member = XapitMember.new(:greeting => "hello")
     data = builder.document_data(member)
     data[:attributes].should eq(:greeting => {:value => "olleh", :text => {}})
+    builder.attributes[:greeting][:_block].should_not be_nil
   end
 
   it "indexes an object by adding it to the current database" do