(Patch from 4.0.5)


mysql-test/r/group_by.result:
  Updated results
mysql-test/t/group_by.test:
  Test for bug
sql/item_cmpfunc.cc:
  Fixed bug in MAX() optimization when used with JOIN and ON expressions
sql/item_cmpfunc.h:
  Fixed bug in MAX() optimization when used with JOIN and ON expressions
sql/opt_sum.cc:
  Fixed bug in MAX() optimization when used with JOIN and ON expressions