We have run into a scenario where replication breaks on slaves when using MIXED replication and temporary tables.
After a session is switched to ROW due to temporary tables existing, all subsequent events for the session should be in ROW. DDL statements affecting Temporary Tables in ROW format should not be logged.
Create index on temporary table is not logged to binlog, since the session should follow ROW logging rules.
On mariadb 10.0.20, create index is logged and breaks replication on slave
On mysql 5.6.26 and 5.6.14, create index is not logged.
Attaching output from both mysql 5.6 and mariadb 10.0.20 attached, and the binlog from mariadb test.