suite)

Under some circumstances a combination of aggregate functions and
GROUP BY in a SELECT query over a VIEW could lead to incorrect
calculation of the result type of the aggregate function. This in
turn could result in incorrect results, or assertion failures on debug
builds.

Fixed by changing the logic in Item_sum_hybrid::fix_fields() so that
the argument's item is dereferenced before calling its type() method.


mysql-test/r/view.result:
  Added a test case for bug #33049.
mysql-test/t/view.test:
  Added a test case for bug #33049.
sql/item_sum.cc:
  When calculating the result type of an aggregate function, dereference
  the argument's item before calling its type() method.