to Crash": the bug was that due to non-standard name
resolution precedence in stored procedures (See Bug#5967)
a stored procedure variable took precedence over a table column
when the arguments for VALUES() function were resolved.
The implementation of VALUES() function was not designed to work
with Item_splocal and crashed.
VALUES() function is non-standard. It can refer to, and
is meaningful for, table columns only. The patch disables SP 
variables as possible arguments of VALUES() function.