mysql-test/r/negation_elimination.result:
new tests of negation elimination
mysql-test/t/negation_elimination.test:
new tests of negation elimination
sql/item.h:
test of boolean functions added
sql/item_cmpfunc.cc:
NOT subtree is already checked, so wee need to return just argument
sql/item_cmpfunc.h:
test of boolean functions added
sql/mysql_priv.h:
'place' to detect WHERE clause
sql/sql_parse.cc:
function for creation negated expression
sql/sql_select.cc:
removed unused function
sql/sql_select.h:
removed unused function
sql/sql_yacc.yy:
'place' to detect WHERE clause
