[#MDEV-18902] Uninitialized variable in recv_parse_log_recs() comparison type==MLOG

The following comparison may compare an uninitialized type when the redo log parsing buffer runs out (ptr==end_ptr), potentially causing an incorrect claim that the redo log is corrupted:

			len = recv_parse_log_rec(

				&type, ptr, end_ptr, &space, &page_no,

				false, &body);

			if (recv_sys->found_corrupt_log

			    || type == MLOG_CHECKPOINT

			    || (ptr != end_ptr

				&& (*ptr & MLOG_SINGLE_REC_FLAG))) {

10.2 69abd43703fcf68c4cf1056bf5bd56c690de5b4e
innodb.log_data_file_size '4k,innodb' w7 [ fail ] Found warnings/errors in server log file!
Test ended at 2019-03-12 13:45:57
line
==372== Conditional jump or move depends on uninitialised value(s)
==372== at 0xC03A1E: recv_parse_log_recs(unsigned long, store_t, bool) (log0recv.cc:2701)
==372== by 0xC048CF: recv_scan_log_recs(unsigned long, store_t, unsigned char const, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) (log0recv.cc:3102)
==372== by 0xC04DCC: recv_group_scan_log_recs(log_group_t, unsigned long, unsigned long, bool) (log0recv.cc:3197)
==372== by 0xC060DD: recv_recovery_from_checkpoint_start(unsigned long) (log0recv.cc:3520)
==372== by 0xD21754: innobase_start_or_create_for_mysql() (srv0start.cc:2192)
==372== by 0xB5CB1B: innobase_init(void*) (ha_innodb.cc:4393)

[MDEV-18902] Uninitialized variable in recv_parse_log_recs() comparison type==MLOG_CHECKPOINT Created: 2019-03-12 Updated: 2019-03-12 Resolved: 2019-03-12
Status:	Closed
Project:	MariaDB Server
Component/s:	mariabackup, Storage Engine - InnoDB
Affects Version/s:	10.2.2, 10.3.0, 10.4.0
Fix Version/s:	10.2.23, 10.3.14, 10.4.4

[MDEV-18902] Uninitialized variable in recv_parse_log_recs() comparison type==MLOG_CHECKPOINT Created: 2019-03-12 Updated: 2019-03-12 Resolved: 2019-03-12