Bug #49910: Behavioural change in SELECT/WHERE on YEAR(4) data type                                  
(Original patch by Sinisa Milivojevic)

The YEAR(4) value of 2000 was equal to the "bad" YEAR(4) value of 0000.                              

The get_year_value() function has been modified to not adjust bad                                    
YEAR(4) value to 2000.


mysql-test/r/type_year.result:
  Test case for bug #49910.
mysql-test/t/type_year.test:
  Test case for bug #49910.
sql/item_cmpfunc.cc:
  Bug #49910: Behavioural change in SELECT/WHERE on YEAR(4) data type                                  
  
  The get_year_value() function has been modified to not adjust bad                                    
  YEAR(4) value to 2000.