Description of problem:
As reported on freeipa-users in
https://www.redhat.com/archives/freeipa-users/2016-January/msg00341.html
when anonymous access is disabled and DNS Kerberos TXT Kerberos record is not configured and realm does not match domain, ipa-client-install tries to assume a realm from the domain and then fails as it is different from the provided one:

2016-01-20T14:55:48Z DEBUG [IPA Discovery]
2016-01-20T14:55:48Z DEBUG Starting IPA discovery with domain=<MYDOMAIN>,
servers=['<FQDN IPA SERVER>'], hostname=<FQDN IPA CLIENT>
2016-01-20T14:55:48Z DEBUG Server and domain forced
2016-01-20T14:55:48Z DEBUG [Kerberos realm search]
2016-01-20T14:55:48Z DEBUG Search DNS for TXT record of
_kerberos.<MYDOMAIN>.
2016-01-20T14:55:48Z DEBUG No DNS record found
2016-01-20T14:55:48Z DEBUG [LDAP server check]
2016-01-20T14:55:48Z DEBUG Verifying that <FQDN IPA SERVER> (realm None) is
an IPA server
2016-01-20T14:55:48Z DEBUG Init LDAP connection with: ldap://<FQDN IPA
SERVER>:389
2016-01-20T14:55:48Z DEBUG LDAP Error: Anonymous access not allowed
2016-01-20T14:55:48Z DEBUG Assuming realm is the same as domain: <MYDOMAIN>
2016-01-20T14:55:48Z DEBUG Generated basedn from realm:
dc=<domainoftheservers>
2016-01-20T14:55:48Z DEBUG Discovery result: NO_ACCESS_TO_LDAP;
server=None, domain=<MYDOMAIN>, kdc=None, basedn=<domainoftheservers>
2016-01-20T14:55:48Z DEBUG Validated servers: <FQDN IPA SERVER>
2016-01-20T14:55:48Z DEBUG will use discovered domain: <MYDOMAIN>
2016-01-20T14:55:48Z DEBUG Using servers from command line, disabling DNS
discovery
2016-01-20T14:55:48Z DEBUG will use provided server: <FQDN IPA SERVER>
2016-01-20T14:55:48Z DEBUG will use discovered realm: <MYDOMAIN>
2016-01-20T14:55:48Z ERROR The provided realm name [<MYREALM>] does not
match discovered one [<MYDOMAIN>]
2016-01-20T14:55:48Z DEBUG (<MYDOMAIN>: Assumed same as domain)
2016-01-20T14:55:48Z ERROR Installation failed. Rolling back changes.
2016-01-20T14:55:48Z ERROR IPA client is not configured on this system.
Version-Release number of selected component (if applicable):


In such case, instead of assuming realm, client should rather accept the one passed via option.

How reproducible:
Always

Steps to Reproduce:
1. Configure FreeIPA server without DNS, with domain different than realm, with anonymous access disabled
2. Install client with --server, --domain, --realm options
3.

Actual results:
Installation fails

Expected results:
Installation succeeds

Additional info: