Issue #2130 has been updated by Larry Kyrala. More context about how I discovered this: I was passing the output of CGI.unescapeHTML() to ActiveSupport::Multibyte::Char.g_unpack() and received the following exception: (ActiveSupport::Multibyte::EncodingError) "malformed UTF-8 character" Investigating this problem led to finding the bug above. ---------------------------------------- http://redmine.ruby-lang.org/issues/show/2130 ---------------------------------------- http://redmine.ruby-lang.org