* lib/uri/common.rb (URI.decode_www_form): scrub string if decoded
  bytes are invalid for the encoding.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40820 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* string.c (str_scrub0): added for refactoring.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40821 b2dd03c8-39d4-4d8f-98ff-823fe69b080e