Comment 5 for bug 1250375

As I understand from discussion at https://bugs.launchpad.net/percona-xtradb-cluster/+bug/1228304, the only purpose of copying the last binlog file is to get GTID info from it later. It's not clear what precisely is required by Galera, but I assume it is Executed_Gtid_Set which is later assigned to gtid_purged.

XtraBackup stores Executed_Gtid_set (if available) in the xtrabackup_binlog_info file. I understand that other SST methods do not provide GTID sets and thus copying the last binlog file is a workaround for that limitation. But does XtraBackup really need to do that?