Bug #42402 Restore crashes server if tablespace does not exist

Description:
Restore crashes the server if the backup image contains tables originally stored in a tablespace that is no longer around.

How to repeat:
create tablespace tb add datafile 'tblspace' engine=falcon;
create database wa;
use wa;

create table t (s1 int) engine=falcon tablespace tb;
insert into t values (1);

--replace_column 1 #
backup database wa to '1.bup';

drop database wa;
drop tablespace tb engine=falcon;

restore from '1.bup';
--> crash

Suggested fix:
The problem is in si_objects.cc:find_tablespace

The current code assumes that there will be exactly one tablespace with this name in the server, otherwise an assertion is triggered:

2722: DBUG_ASSERT(ed_result_set->size() == 1);

However, it is ok for this method to return nothing. The backup code is written to handle this case, and will try to create the tablespace.

mysql> drop database wa;
Query OK, 1 row affected (0.01 sec)

mysql> drop tablespace tb engine=falcon;
Query OK, 0 rows affected (0.00 sec)

mysql> 
mysql> restore from '1.bup';
ERROR 2013 (HY000): Lost connection to MySQL server during query
mysql>

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/68387

2784 Jorgen Loland	2009-03-05
      Bug#42402 - Restore crashes server if tablespace does not exist
      
      Before, RESTORE would crash if the backup image contained tables originally stored in a tablespace that no longer exists at RESTORE time.
      
      With this patch, the tablespace is recreated like it was at BACKUP time if it does not exist when RESTORE is executed.

Good to push.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/68462

2790 Jorgen Loland	2009-03-06
      Bug#42402 - Restore crashes server if tablespace does not exist
            
      Before, RESTORE would crash if the backup image contained tables originally stored
      in a tablespace that no longer exists at RESTORE time.
            
      With this patch, the tablespace is recreated like it was at BACKUP time if it does
      not exist when RESTORE is executed.

Pushed into 6.0.11-alpha (revid:alik@sun.com-20090326121822-pt84kzxxayzho4mn) (version source revid:charles.bell@sun.com-20090309134019-vr480npdp30f2gvh) (merge vers: 6.0.11-alpha) (pib:6)

Noted in 6.0.11 changelog.

Previously, RESTORE would crash if the backup image contained tables
originally stored in a tablespace that no longer existed at RESTORE
time. Now the tablespace is recreated like it was at BACKUP DATABASE
time if it does not exist when RESTORE is executed.