Description of problem:
 I bring my setup to state when have IPA there & I can't remove/add same/another domain. Looks like there's no AdUser in the DB (the field is empty). DomainName is filled ipa-domain.rhev.lab.eng.brq.redhat.com


[root@ps-ad2-set ~]# rhevm-manage-domains -action=validate
Exception in thread "main" java.lang.NullPointerException
        at org.ovirt.engine.core.utils.kerberos.ManageDomains.constructUPN(ManageDomains.java:94)
        at org.ovirt.engine.core.utils.kerberos.ManageDomains.checkKerberosConfiguration(ManageDomains.java:617)
        at org.ovirt.engine.core.utils.kerberos.ManageDomains.testConfiguration(ManageDomains.java:772)
        at org.ovirt.engine.core.utils.kerberos.ManageDomains.validate(ManageDomains.java:352)
        at org.ovirt.engine.core.utils.kerberos.ManageDomains.runCommand(ManageDomains.java:251)
        at org.ovirt.engine.core.utils.kerberos.ManageDomains.main(ManageDomains.java:166)


[root@ps-ad2-set ~]# rhevm-manage-domains -action=delete -user=vdcadmin -interactive -domain=ipa-domain.rhev.lab.eng.brq.redhat.com -addPermissions -provider=IPA
WARNING: Domain ipa-domain.rhev.lab.eng.brq.redhat.com is the last domain in the configuration. After deleting it you will have to either add another domain, or to use the internal admin user in order to login.
Error with output, no default message to show. sorry..


manage-log-domains:
==============================
2012-09-18 14:13:10,089 INFO  [org.ovirt.engine.core.utils.kerberos.ManageDomainsDAOImpl] Setting value for AdUserName to
2012-09-18 14:13:10,881 INFO  [org.ovirt.engine.core.utils.kerberos.ManageDomainsDAOImpl] Setting value for AdUserPassword to
2012-09-18 14:13:11,974 ERROR [org.ovirt.engine.core.utils.kerberos.ManageDomains] Error with output, no default message to show. sorry..


Version-Release number of selected component (if applicable):
si18

How reproducible:
rarely 

Steps to Reproduce:
1. see above
2.
3.
  
Actual results:
Can't remove IPA domain

Expected results:


Additional info: