When an ambiguous field name is used in a group by clause a warning is issued
in the find_order_in_list function by a call to push_warning_printf.
An expression that was not always valid was passed to this call as the field
name parameter.


mysql-test/r/view.result:
  Added a test case for bug #16382.
mysql-test/t/view.test:
  Added a test case for bug #16382.