There were multiple problems here
* wsrep_trx_fragment_size should not be set when wsrep is disabled or provider is not loaded
* wsrep_trx_fragment_unit should not be set when wsrep is disabled or provider is not loaded
* wsrep_debug has no effect if wsrep is disabled or provider is not loaded
* wsrep_start_position should not be set when wsrep is disabled or provider is not loaded any other value than default
* wsrep_start_position should be changed only when we are joiner or initialized
* wsrep_start_position should be allowed to set only a value that exits, thus
we need to add error handling to wsrep_sst_complete
- Validate the specified wsrep_start_position value by also
checking the return status of wsrep->sst_received. This also
ensures that changes in wsrep_start_position is not allowed
when the node is not in JOINING state.
- Do not allow decrease in seqno within same UUID.
- The initial checkpoint in SEs should be [0...:-1].
1. factored XID-related functions to a separate wsrep_xid.cc unit.
2. refactored them to take refrences instead of pointers where appropriate
3. implemented wsrep_get/set_SE_position to take wsrep_uuid_t and wsrep_seqno_t instead of XID
4. call wsrep_set_SE_position() in wsrep_sst_received() to reinitialize SE checkpoint after SST was received, avoid assert() in setting code by first checking current position.
Merged lp:maria/maria-10.0-galera up to revision 3879.
Added a new functions to handler API to forcefully abort_transaction,
producing fake_trx_id, get_checkpoint and set_checkpoint for XA. These
were added for future possiblity to add more storage engines that
could use galera replication.