MDEV-15682 mariabackup.unsupported_redo fails in buildbot with wrong result code

Skip the test mariabackup.unsupported_redo if a checkpoint occurred
before mariabackup --backup completed. Remove the slow shutdowns
and restarts which were attempting to prevent the checkpoints from
occurring.

mysql-test/suite/innodb/include/no_checkpoint_end.inc

 # Check that the latest checkpoint in the redo log files
 # is not newer than the checkpoint sampled by no_checkpoint_start.inc
 
+if (!$no_checkpoint_kill) {
 --source include/kill_mysqld.inc
+}
 
 perl;
 my $cp = $ENV{CHECKPOINT_LSN};
@@ -22,7 +24,8 @@ my $cp2 = $cp2hi << 32 | $cp2lo;
 open(OUT, ">$ENV{MYSQLTEST_VARDIR}/log/check.txt") || die;
 
 if ($cp1 > $cp || $cp2 > $cp) {
-   print OUT "--source include/start_mysqld.inc\n";
+   print OUT "--source include/start_mysqld.inc\n"
+   unless $ENV{no_checkpoint_kill};
    print OUT "$ENV{CLEANUP_IF_CHECKPOINT}\n";
    print OUT "--skip Extra checkpoint 1 after $cp";
    print OUT " ($no1hi:$no1lo=$cp1,$no2hi:$no2lo=$cp2)\n";

mysql-test/suite/mariabackup/unsupported_redo.result

@@ -5,8 +5,10 @@ call mtr.add_suppression("InnoDB: If you are installing InnoDB, remember that yo
 call mtr.add_suppression("InnoDB: Ignoring tablespace for `test`\\.`t21` because it could not be opened");
 call mtr.add_suppression("InnoDB: Cannot open datafile for read-only: ");
 call mtr.add_suppression("Table .* in the InnoDB data dictionary has tablespace id .*, but tablespace with that id or name does not exist");
+SELECT @@GLOBAL.innodb_flush_log_at_trx_commit;
+@@GLOBAL.innodb_flush_log_at_trx_commit
+1
 CREATE TABLE t1(i INT PRIMARY KEY auto_increment, a int) ENGINE INNODB;
-SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
 ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
 # Fails during full backup
 DROP TABLE t1;
@@ -14,7 +16,6 @@ CREATE TABLE t1(i INT PRIMARY KEY auto_increment, a int) ENGINE INNODB;
 INSERT INTO t1(a) select 1 union select 2 union select 3;
 # Create full backup , modify table, then fails during creation of
 #		incremental/differential backup
-SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
 ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
 DROP TABLE t1;
 CREATE TABLE t1(i INT) ENGINE INNODB;
@@ -22,7 +23,6 @@ INSERT INTO t1 VALUES(1);
 CREATE TABLE t21(i INT) ENGINE INNODB;
 INSERT INTO t21 VALUES(1);
 CREATE TABLE t2(i int) ENGINE INNODB;
-SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
 ALTER TABLE t21 FORCE, ALGORITHM=INPLACE;
 # Create partial backup (excluding table t21), Ignore the
 # unsupported redo log for the table t21.

mysql-test/suite/mariabackup/unsupported_redo.test

@@ -10,11 +10,9 @@ call mtr.add_suppression("Table .* in the InnoDB data dictionary has tablespace
 let $basedir=$MYSQLTEST_VARDIR/tmp/backup;
 let $incremental_dir=$MYSQLTEST_VARDIR/tmp/backup_inc1;
 
+SELECT @@GLOBAL.innodb_flush_log_at_trx_commit;
 CREATE TABLE t1(i INT PRIMARY KEY auto_increment, a int) ENGINE INNODB;
-
-SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
---source include/restart_mysqld.inc
-
+--source ../../suite/innodb/include/no_checkpoint_start.inc
 ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
 
 # Below mariabackup operation may complete successfully if checkpoint happens
@@ -22,11 +20,25 @@ ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
 
 echo # Fails during full backup;
 --disable_result_log
---error 1
+--error 0,1
 exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf  --backup --target-dir=$basedir;
 --enable_result_log
 
 DROP TABLE t1;
+
+--let MYSQLD_DATADIR=$basedir/
+perl;
+open(OUT, ">$ENV{MYSQLTEST_VARDIR}/log/check.txt") || die;
+print OUT '
+--let no_checkpoint_end=1
+--let CLEANUP_IF_CHECKPOINT=rmdir $basedir;
+--source ../../suite/innodb/include/no_checkpoint_end.inc
+--exit Backup failed to fail despite MLOG_INDEX_LOAD record
+' if (-f "$ENV{MYSQLD_DATADIR}/xtrabackup_info");
+close(OUT);
+EOF
+--source $MYSQLTEST_VARDIR/log/check.txt
+--remove_file $MYSQLTEST_VARDIR/log/check.txt
 rmdir $basedir;
 
 CREATE TABLE t1(i INT PRIMARY KEY auto_increment, a int) ENGINE INNODB;
@@ -39,18 +51,30 @@ INSERT INTO t1(a) select 1 union select 2 union select 3;
 exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf  --backup --target-dir=$basedir;
 --enable_result_log
 
-SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
---source include/restart_mysqld.inc
+--source ../../suite/innodb/include/no_checkpoint_start.inc
 ALTER TABLE t1 FORCE, ALGORITHM=INPLACE;
 
 --disable_result_log
---error 1
+--error 0,1
 exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf  --backup --target-dir=$incremental_dir --incremental-basedir=$basedir;
 --enable_result_log
 
 DROP TABLE t1;
-rmdir $basedir;
-rmdir $incremental_dir;
+
+--let MYSQLD_DATADIR=$incremental_dir/
+perl;
+open(OUT, ">$ENV{MYSQLTEST_VARDIR}/log/check.txt") || die;
+print OUT '
+--let no_checkpoint_end=1
+--let CLEANUP_IF_CHECKPOINT=rmdir $basedir;rmdir $incremental_dir;
+--source ../../suite/innodb/include/no_checkpoint_end.inc
+--exit Backup failed to fail despite MLOG_INDEX_LOAD record
+' if (-f "$ENV{MYSQLD_DATADIR}/xtrabackup_info");
+close(OUT);
+EOF
+--source $MYSQLTEST_VARDIR/log/check.txt
+--remove_file $MYSQLTEST_VARDIR/log/check.txt
+rmdir $basedir;rmdir $incremental_dir;
 
 CREATE TABLE t1(i INT) ENGINE INNODB;
 INSERT INTO t1 VALUES(1);
@@ -62,8 +86,6 @@ let $targetdir=$MYSQLTEST_VARDIR/tmp/bk;
 
 CREATE TABLE t2(i int) ENGINE INNODB;
 
-SET GLOBAL INNODB_FAST_SHUTDOWN = 0;
---source include/restart_mysqld.inc
 ALTER TABLE t21 FORCE, ALGORITHM=INPLACE;
 
 --echo # Create partial backup (excluding table t21), Ignore the