Bug#7834 Illegal mix of collations in IN operator
  IN was the first function supporting 
  character set convertion.
  agg_arg_charsets() was written afterwards,
  which is more flexible.
  Now IN just reuses this function.


sql/item_cmpfunc.cc:
  Bug#7834 Illegal mix of collations in IN operator
  IN was the first function supporting 
  character set convertion.
  agg_arg_charsets() was written afterwards,
  which is more flexible.
  Now IN just reuses this function.