[test] extra ASN.1 test instantiating with nil

src/test/ruby/test_asn1.rb

@@ -45,9 +45,7 @@ def test_constants
     assert_equal universal_tag_name, OpenSSL::ASN1::UNIVERSAL_TAG_NAME
   end
 
-  require 'pp'
-
-  def _test_parse_infinite_length_sequence # borrowed from Krypt
+  def _test_parse_infinite_length_sequence; require 'pp' # borrowed from Krypt
     raw = [%w{30 80 04 01 01 02 01 01 00 00}.join("")].pack("H*")
     pp asn1 = OpenSSL::ASN1.decode(raw)
 
@@ -66,6 +64,11 @@ def _test_parse_infinite_length_sequence # borrowed from Krypt
     assert_equal(raw, asn1.to_der)
   end
 
+  def test_simple_to_der
+    assert_equal "0\x00", OpenSSL::ASN1::Sequence.new(nil).to_der
+    assert_equal "1\x00", OpenSSL::ASN1::Set.new(nil).to_der
+  end
+
   def test_constructive
     oct = OpenSSL::ASN1::OctetString.new("")
     assert_equal "\x04\x00", oct.to_der