Description of problem:
getent failed to fetch netgroup information after changing
default_domain_suffix to ADdomin in /etc/sssd/sssd.conf

Version-Release number of selected component (if applicable):
sssd-1.15.2-37.el7.x86_64
ipa-server-4.5.0-13.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
Description of problem:
getent failed to fetch netgroup information after changing
default_domain_suffix to ADdomin in /etc/sssd/sssd.conf


:: [  BEGIN   ] :: Running 'kdestroy -A'
:: [   PASS   ] :: Command 'kdestroy -A' (Expected 0, got 0)
:: [  BEGIN   ] :: Running 'echo Secret123|kinit admin'
Password for admin@SUDOEXSM37.TEST:
:: [   PASS   ] :: Command 'echo Secret123|kinit admin' (Expected 0, got 0)
:: [  BEGIN   ] :: Running 'ipa netgroup-add --desc test_netgroup ng_test'
------------------------
Added netgroup "ng_test"
------------------------
  Netgroup name: ng_test
  Description: test_netgroup
  NIS domain name: sudoexsm37.test
  IPA unique ID: defa9578-45da-11e7-b3eb-5254007eedd6
:: [   PASS   ] :: Command 'ipa netgroup-add --desc test_netgroup ng_test'
(Expected 0, got 0)

:: [  BEGIN   ] :: Running 'awk '/\[sssd\]/,/^$/' /etc/sssd/sssd.conf'
[sssd]
default_domain_suffix = pne.qe
debug_level = 10
services = nss, pam, ssh, sudo

:: [   PASS   ] :: Command 'awk '/\[sssd\]/,/^$/' /etc/sssd/sssd.conf'
(Expected 0, got 0)

:: [  BEGIN   ] :: Running 'service sssd stop; rm -rf /var/lib/sss/{db,mc}/*;
service sssd start'
Redirecting to /bin/systemctl stop sssd.service
Redirecting to /bin/systemctl start sssd.service
:: [   PASS   ] :: Command 'service sssd stop; rm -rf /var/lib/sss/{db,mc}/*;
service sssd start' (Expected 0, got 0)

:: [  BEGIN   ] :: Running 'getent netgroup ng_test >
ipa_trust_func_bug_1127757.rlkQ8B 2>&1'
:: [   FAIL   ] :: Command 'getent netgroup ng_test >
ipa_trust_func_bug_1127757.rlkQ8B 2>&1' (Expected 0, got 2)
:: [   FAIL   ] :: File 'ipa_trust_func_bug_1127757.rlkQ8B' should contain
'ipauser1'

:: [   FAIL   ] :: File '/var/log/sssd/sssd_nss.log' should contain
'sss_dp_issue_request.*ng_test@sudoexsm37.test'



Expected results:
netgroups shouldn't be affected by default domain suffix

Additional info:

getting the expected result by adding IPAdomain with netgroup (getent netgroup
<netgroupname@IPADOMAIN>)
# getent netgroup ng_test@sudoexsm37.test
ng_test@sudoexsm37.test (-,ipauser1,sudoexsm37.test)

Old bug https://bugzilla.redhat.com/show_bug.cgi?id=1312275 with the same kind
of issue was verified in Rhle 6.5 and sssd-1.11.6-20.el6