the index option is always created if the type is one of references or...

the index option is always created if the type is one of references or belongs_to. Refactoring it to a simpler form and fixing the build

railties/lib/rails/generators/generated_attribute.rb

@@ -22,8 +22,10 @@ def parse(column_definition)
 
           type, attr_options = *parse_type_and_options(type)
 
-          references_index = type.in?(%w(references belongs_to)) && UNIQ_INDEX_OPTIONS.include?(has_index) ? {:unique => true} : true
-          attr_options.merge!({:index => references_index}) if references_index
+          if type.in?(%w(references belongs_to))
+            references_index = UNIQ_INDEX_OPTIONS.include?(has_index) ? {:unique => true} : true
+            attr_options.merge!({:index => references_index})
+          end
 
           new(name, type, has_index, attr_options)
         end