MDEV-30114 Incremental prepare fails when innodb_undo_tablespaces > 0

- Mariabackup fails to open the undo tablespaces while applying delta
files to the corresponding data file. Mariabackup opens the
undo tablespaces first time in srv_undo_tablespaces_init() and does
tries to open the undo tablespaces in xtrabackup_apply_deltas() with
conflicting mode and leads to the failure.

- Mariabackup should close the undo tablespaces before applying
the incremental delta files.

extra/mariabackup/xtrabackup.cc

@@ -3799,6 +3799,21 @@ static dberr_t xb_assign_undo_space_start()
 	return error;
 }
 
+/** Close all undo tablespaces while applying incremental delta */
+static void xb_close_undo_tablespaces()
+{
+  if (srv_undo_space_id_start == 0)
+    return;
+  for (ulint space_id= srv_undo_space_id_start;
+       space_id < srv_undo_space_id_start + srv_undo_tablespaces_open;
+       space_id++)
+  {
+     fil_space_t *space= fil_space_get(space_id);
+     ut_ad(space);
+     space->close();
+  }
+}
+
 /****************************************************************************
 Populates the tablespace memory cache by scanning for and opening data files.
 @returns DB_SUCCESS or error code.*/
@@ -3861,6 +3876,11 @@ xb_load_tablespaces()
 	if (err != DB_SUCCESS) {
 		return(err);
 	}
+
+	if (srv_operation == SRV_OPERATION_RESTORE_DELTA) {
+		xb_close_undo_tablespaces();
+	}
+
 	DBUG_MARIABACKUP_EVENT("after_load_tablespaces", 0);
 	return(DB_SUCCESS);
 }

mysql-test/suite/mariabackup/apply-log-only-incr.test

 --source include/have_innodb.inc
+--source include/innodb_undo_tablespaces.inc
 
 call mtr.add_suppression("InnoDB: New log files created");
 

mysql-test/suite/mariabackup/incremental_backup.test

 --source include/have_aria.inc
 --source include/innodb_page_size.inc
+--source include/innodb_undo_tablespaces.inc
 
 # see suite.pm "check for exact values, in case the default changes to be small everywhere"
 if (`select @@max_binlog_stmt_cache_size = 4294963200 and @@innodb_page_size = 65536`) {

mysql-test/suite/mariabackup/incremental_compressed.test

 --source include/have_innodb.inc
 --source include/have_partition.inc
+--source include/innodb_undo_tablespaces.inc
 
 let $basedir=$MYSQLTEST_VARDIR/tmp/backup;
 let $incremental_dir=$MYSQLTEST_VARDIR/tmp/backup_inc1;

mysql-test/suite/mariabackup/incremental_ddl_before_backup.test

 --source include/have_debug.inc
+--source include/innodb_undo_tablespaces.inc
 
 call mtr.add_suppression("InnoDB: New log files created");
 

mysql-test/suite/mariabackup/incremental_ddl_during_backup.test

 --source include/have_debug.inc
+--source include/innodb_undo_tablespaces.inc
 
 call mtr.add_suppression("InnoDB: New log files created");
 

mysql-test/suite/mariabackup/incremental_encrypted.test

 --source include/innodb_page_size.inc
+--source include/innodb_undo_tablespaces.inc
 
 if (!$EXAMPLE_KEY_MANAGEMENT_SO)
 {

mysql-test/suite/mariabackup/incremental_newdb_while_backup.test

 --source include/have_innodb.inc
 --source include/have_debug.inc
+--source include/innodb_undo_tablespaces.inc
 
 call mtr.add_suppression("InnoDB: New log files created");
 

mysql-test/suite/mariabackup/log_page_corruption.test

 --source include/have_debug.inc
 --source include/no_valgrind_without_big.inc
+--source include/innodb_undo_tablespaces.inc
 
 --echo ########
 --echo # Test for generating "innodb_corrupted_pages" file during full and

mysql-test/suite/mariabackup/unsupported_redo.test

 --source include/have_innodb.inc
+--source include/innodb_undo_tablespaces.inc
 call mtr.add_suppression("InnoDB: New log files created");
 call mtr.add_suppression("InnoDB: Operating system error number .* in a file operation");
 call mtr.add_suppression("InnoDB: The error means the system cannot find the path specified");

mysql-test/suite/mariabackup/xb_partition.test

 #--source include/innodb_page_size.inc
 --source include/have_partition.inc
+--source include/innodb_undo_tablespaces.inc
 
 CREATE TABLE t1(a INT) ENGINE=InnoDB;
 INSERT INTO t1 VALUES (1), (2), (3);