A partial bugfix to a multibyte charset / column prefix index bug: my_charpos() does not handle right some cases, we try to mask the bug for ASCII chars < 128 in the UTF-8 charset


sql/ha_innodb.cc:
  A partial bugfix to a multibyte charset / column prefix index bug: my_charpos() does not handle right some cases, we try to mask the bug for ASCII chars < 128 in the UTF-8 charset