Symbolize the keys of overwritten parameters. Really closes #1909.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2147 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/lib/action_controller/url_rewriter.rb

@@ -37,7 +37,7 @@ def rewrite_path(options)
         options = options.symbolize_keys
         options.update(options[:params].symbolize_keys) if options[:params]
         if (overwrite = options.delete(:overwrite_params))
-          options.update(@parameters)
+          options.update(@parameters.symbolize_keys)
           options.update(overwrite)
         end
         RESERVED_OPTIONS.each {|k| options.delete k}