Ruby

parse.y: check multibyte char

• parse.y (parser_precise_mbclen): check invalid multibyte char at
  skipping strings following ?x literal string, not to stuck in
  a infinite loop. [ruby-core:81746] [Bug #13672]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59161 b2dd03c8-39d4-4d8f-98ff-823fe69b080e