When executing drop view statement on the master, the statement is written
into bin-log without checking for possible errors, so the statement would 
always be bin-logged with error code cleared even if some error might occur, 
for example, some of the views being dropped does not exist. This would cause 
failure on the slave.

Writing bin-log after check for errors, if at least one view has been dropped
the query is bin-logged possible with an error.


sql/sql_view.cc:
  Writing bin-log after check for errors, if at least one view has been dropped
  the query is bin-logged possible with an error.
mysql-test/r/rpl_drop_view.result:
  Add test result for bug#30998
mysql-test/t/rpl_drop_view.test:
  Add test for bug#30998