commit f2bb618fa36c7a80fea62cc4945b166bfb22c130
Author: Florian Best <best@univention.de>
Date:   Fri Aug 9 11:01:25 2019 +0200

    Bug #49874: prevent CONSTRAINT_VIOLATION if not dnsRecords are set
    
    Traceback (most recent call last):
      File "/usr/lib/python2.7/dist-packages/univention/s4connector/__init__.py", line 910, in __sync_file_from_ucs
        if ((old_dn and not self.sync_from_ucs(key, mapped_object, pre_mapped_ucs_dn, unicode(old_dn, 'utf8'), old, new)) or (not old_dn and not self.sync_from_ucs(key, mapped_object, pre_mapped_ucs_dn, old_dn, old, new))):
      File "/usr/lib/python2.7/dist-packages/univention/s4connector/s4/__init__.py", line 2520, in sync_from_ucs
        self.property[property_type].con_sync_function(self, property_type, object)
      File "/usr/lib/python2.7/dist-packages/univention/s4connector/s4/dns.py", line 1640, in ucs2con
        s4_host_record_create(s4connector, object)
      File "/usr/lib/python2.7/dist-packages/univention/s4connector/s4/dns.py", line 959, in s4_host_record_create
        dnsNodeDn = s4_dns_node_base_create(s4connector, object, dnsRecords)
      File "/usr/lib/python2.7/dist-packages/univention/s4connector/s4/dns.py", line 904, in s4_dns_node_base_create
        __create_s4_dns_node(s4connector, dnsNodeDn, relativeDomainNames, dnsRecords)
      File "/usr/lib/python2.7/dist-packages/univention/s4connector/s4/dns.py", line 507, in __create_s4_dns_node
        s4connector.lo_s4.lo.add_s(dnsNodeDn, al)
      File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line 210, in add_s
        return self.result(msgid,all=1,timeout=self.timeout)
      File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line 503, in result
        resp_type, resp_data, resp_msgid = self.result2(msgid,all,timeout)
      File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line 507, in result2
        resp_type, resp_data, resp_msgid, resp_ctrls = self.result3(msgid,all,timeout)
      File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line 514, in result3
        resp_ctrl_classes=resp_ctrl_classes
      File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line 521, in result4
        ldap_result = self._ldap_call(self._l.result4,msgid,all,timeout,add_ctrls,add_intermediates,add_extop)
      File "/usr/lib/python2.7/dist-packages/ldap/ldapobject.py", line 106, in _ldap_call
        result = func(*args,**kwargs)
    CONSTRAINT_VIOLATION: {'info': "attribute 'dnsRecord' on 'DC=n0vg5ew5si,DC=zv3pf30r1a.fzxtw3ascy,CN=MicrosoftDNS,DC=DomainDnsZones,DC=autotest091,DC=local' specified, but with 0 values (illegal)", 'desc': 'Constraint violation'}

diff --git a/services/univention-s4-connector/modules/univention/s4connector/s4/dns.py b/services/univention-s4-connector/modules/univention/s4connector/s4/dns.py
index 931dcecf92..c7e3bd2f3b 100644
--- a/services/univention-s4-connector/modules/univention/s4connector/s4/dns.py
+++ b/services/univention-s4-connector/modules/univention/s4connector/s4/dns.py
@@ -500,7 +500,8 @@ def __create_s4_dns_node(s4connector, dnsNodeDn, relativeDomainNames, dnsRecords
 
 	al.append(('objectClass', ['top', 'dnsNode']))
 	al.append(('dc', relativeDomainNames))
-	al.append(('dnsRecord', dnsRecords))
+	if dnsRecords:
+		al.append(('dnsRecord', dnsRecords))
 
 	ud.debug(ud.LDAP, ud.INFO, '__create_s4_dns_node: dn: %s' % dnsNodeDn)
 	ud.debug(ud.LDAP, ud.INFO, '__create_s4_dns_node: al: %s' % al)