leads to an assertion failure

Any run-time error in stored function (like recursive function
call or update of table that is already updating by statement
which invoked this stored function etc.) that was used in some
expression of the single-table UPDATE statement caused an
assertion failure.
Multiple-table UPDATE (as well as INSERT and both single- and
multiple-table DELETE) are not affected.


mysql-test/r/update.result:
  Added test case for bug #40745.
mysql-test/t/update.test:
  Added test case for bug #40745.
sql/sql_update.cc:
  Bug #40745: Error during WHERE clause calculation in UPDATE
              leads to an assertion failure
  
  The mysql_update function has been updated to take into account
  the status of invoked stored functions before setting the status
  of whole UPDATE query to OK.