Add test for code_point_limit

Only supported on JRuby currently.

test/psych/test_parser.rb

@@ -384,6 +384,25 @@ def test_event_location
  [:end_stream, [2, 0, 2, 0]]], events
  end
 
+ if Psych::Parser.method_defined?(:code_point_limit)
+ def test_code_point_limit
+ yaml = "foo: bar\n" * 500_000
+ assert_raise(org.snakeyaml.engine.v2.exceptions.YamlEngineException) do
+ Psych.load(yaml)
+ end
+
+ assert_nothing_raised do
+ begin
+ old_code_point_limit, Psych::Parser.code_point_limit = Psych::Parser::code_point_limit, 5_000_000
+
+ Psych.load(yaml)
+ ensure
+ Psych::Parser.code_point_limit = old_code_point_limit
+ end
+ end
+ end
+ end
+
  def assert_called call, with = nil, parser = @parser
  if with
  call = parser.handler.calls.find { |x|