Description of problem:
spacewalk-schema-upgrade (from spacewalk-schema package) is unable to
upgrade database schema when upgrading from schema older than 5.2.0.

Version-Release number of selected component (if applicable):
spacewalk-schema-0.5.10-1
satellite-schema-5.3.0.10-1

How reproducible:
Always

Steps to Reproduce:
1. Install a Satellite, older than 5.2.0
2. Upgrade to 5.3.0 (./install.pl --upgrade ...)
3. Proceed with schema upgrade (use spacewalk-schema-upgrade script)
  
Actual results:
Schema upgrade fails with following error present in sql upgrade log:
...
SQL> declare
  2     invalid_schema_version exception;
  3     cursor valid_evrs is
  4        select   1
  5        from  dual
  6        where :evr_id in (
  7           lookup_evr('','5.0.0','26')
  8           );
  9  begin
 10     for vevr in valid_evrs loop
 11        return;
 12     end loop;
 13     raise invalid_schema_version;
 14  end;
 15  /
declare
*
ERROR at line 1:
ORA-06510: PL/SQL: unhandled user-defined exception 
ORA-06512: at line 13 

Expected results:
Schema upgrade proceeds.

Additional info:
* On a Satellite 5.0.0 before upgrade:

# sqlplus ...
SQL> select * from rhnversioninfo;

LABEL                                                               NAME_ID
---------------------------------------------------------------- ----------
    EVR_ID CREATED   MODIFIED
---------- --------- ---------
schema                                                                    6
         5 18-FEB-09 18-FEB-09

* What spacewalk-schema-upgrade does before it actually executes all
sql scripts in the upgrade path:

update rhnVersionInfo
        set label = 'schema-from-' || to_char(created, 'YYYYMMDD-HH24MISS'),
                modified = sysdate
        where label = 'schema';
        commit;

* What we do in at the beginning of every sql upgrade script:

variable evr_id number;
variable epoch varchar2(16);
variable version varchar2(64);
variable release varchar2(64);
variable message varchar2(80);

declare
   cursor evrs is
      select   e.id, e.epoch, e.version, e.release, e.evr
      from  rhnPackageEVR e,
         rhnVersionInfo rvi
      where rvi.label = 'schema'
         and rvi.name_id =
            lookup_package_name('rhn-satellite-schema')
         and rvi.evr_id = e.id;
   cursor valid_evrs is
      select   1
      from  dual
      where :evr_id in (
         lookup_evr('','5.0.0','26')
         );
begin
   :evr_id := null;
   :message := 'XXX Invalid satellite schema version.';
   for evr in evrs loop
      :evr_id := evr.id;
      :epoch := evr.epoch;
      :version := evr.version;
      :release := evr.release;
      :message :=  '*** Schema version is currently ' ||
         evr.evr.as_vre_simple() ||
         ', and will NOT be upgraded';
      for vevr in valid_evrs loop
         :message :=  '*** Schema version is currently ' ||
            evr.evr.as_vre_simple() ||
            ', and will be upgraded';
      end loop;
      return;
   end loop;
end;
/
show errors;

select :message from dual;

declare
   invalid_schema_version exception;
   cursor valid_evrs is
      select   1
      from  dual
      where :evr_id in (
         lookup_evr('','5.0.0','26')
         );
begin
   for vevr in valid_evrs loop
      return;
   end loop;
   raise invalid_schema_version;
end;
/