* lib/rdoc: Update to RDoc master 900de99. Changes include:

Fixed documentation display of constants

  Fixed handling of unknown parsers

* test/rdoc:  ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43962 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/rdoc/test_rdoc_parser.rb

@@ -292,6 +292,16 @@ class TestRDocParser < RDoc::TestCase
     assert_nil parser
   end
 
+  def test_class_use_markup_unknown
+    content = <<-CONTENT
+# :markup: RDoc
+    CONTENT
+
+    parser = @RP.use_markup content
+
+    assert_nil parser
+  end
+
   def test_initialize
     @RP.new @top_level, @fn, '', @options, nil