Call dup not to overwrite original value

Signed-off-by: Yuta Iwama <ganmacs@gmail.com>

Author: ganmacs

lib/fluent/config/section.rb

@@ -58,6 +58,10 @@ def to_h
         @params
       end
 
+      def dup
+        Section.new(@params.dup, @corresponding_config_element.dup)
+      end
+
       def +(other)
         Section.new(self.to_h.merge(other.to_h))
       end

lib/fluent/plugin_helper/http_server.rb

@@ -115,7 +115,7 @@ def stop
       private
 
       def _http_server_overwrite_config(config, opts)
-        conf = config
+        conf = config.dup
         Fluent::PluginHelper::Server::SERVER_TRANSPORT_PARAMS.map(&:to_s).each do |param|
           if opts.key?(param)
             conf[param] = opts[param]

test/config/test_section.rb

@@ -40,8 +40,6 @@ class TestSection < ::Test::Unit::TestCase
             assert_equal("email", s1.send)
             assert_equal("normal", s1.klass)
             assert_equal(5, s1.keys)
-
-            assert_raise(NoMethodError) { s1.dup }
           end
 
           test 'creates object which contains specified hash object itself, including fields with at prefix' do