the error to be sent to the client.


mysql-test/r/select_safe.result:
  Testcase for BUG#8726
mysql-test/t/select_safe.test:
  Testcase for BUG#8726
sql/sql_select.cc:
  Fix for BUG#8726: On ER_TOO_BIG_SELECT set JOIN::error to -1 to cause the error to be sent to the client.