under terms of bug#28875 for better performance.
The change appeared to require more changes in item_cmpfunc.cc,
which is dangerous in 5.0.
    
Conversion between a latin1 column and an ascii string constant
stopped to work.


mysql-test/r/ctype_recoding.result:
  Adding test case.
mysql-test/t/ctype_recoding.test:
  Adding test case.