Description of problem:

Currently when the SDK tries to read an empty list of elements, without a close tag, it fails to detect the end of the list correctly, and it includes the in the list the next elements.

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

4.1.0.a


How reproducible:

Always.


Steps to Reproduce:
1. Make sure that at least one cluster has an empty list of required RNG sources.
2. Use the SDK to list the cluster:

---8<---
import ovirtsdk4 as sdk
import ovirtsdk4.types as types

connection = sdk.Connection(
    url='https://engine41.example.com/ovirt-engine/api',
    username='admin@internal',
    password='...',
    ca_file='ca.pem',
)

clusters_service = connection.system_service().clusters_service()

clusters = clusters_service.list()

for cluster in clusters:
    print("%s: %s" % (cluster.name, cluster.id))

connection.close()
---8<---


Actual results:

Traceback (most recent call last):
  File "./list_clusters.py", line 43, in <module>
    clusters = clusters_service.list()
  File "/files/projects/ovirt-engine-sdk-python/repository/sdk/lib/ovirtsdk4/services.py", line 3028, in list
    return readers.ClusterReader.read_many(reader)
  File "/files/projects/ovirt-engine-sdk-python/repository/sdk/lib/ovirtsdk4/readers.py", line 1791, in read_many
    objs.append(ClusterReader.read_one(reader))
  File "/files/projects/ovirt-engine-sdk-python/repository/sdk/lib/ovirtsdk4/readers.py", line 1744, in read_one
    obj.required_rng_sources = [types.RngSource(s.lower()) for s in Reader.read_strings(reader)]
AttributeError: 'NoneType' object has no attribute 'lower'

(Note that the backtrace may be different, depending on the actual content of the retrived cluster).


Expected results:

This should print the list of cluster names and identifiers:

Default: 00000002-0002-0002-0002-00000000017a
mycluster: 72e982ce-e010-4736-b8ab-dd31a8949f19