fix the team code review comments and fix the unit test

Author: caberos

SoftLayer/managers/network.py

@@ -542,7 +542,10 @@ def list_vlans(self, datacenter=None, vlan_number=None, name=None, limit=100, **
             kwargs['mask'] = DEFAULT_VLAN_MASK
 
         kwargs['iter'] = True
-        return self.account.getNetworkVlans(mask=kwargs['mask'], filter=_filter.to_dict(), limit=limit)
+        if limit > 0:
+            return self.account.getNetworkVlans(mask=kwargs['mask'], filter=_filter.to_dict(), limit=limit)
+        else:
+            return self.account.getNetworkVlans(mask=kwargs['mask'], filter=_filter.to_dict(), iter=True)
 
     def list_securitygroups(self, **kwargs):
         """List security groups."""

tests/managers/network_tests.py

@@ -360,13 +360,14 @@ def test_list_vlans_with_filters(self):
         self.assertEqual(result, fixtures.SoftLayer_Account.getNetworkVlans)
         _filter = {
             'networkVlans': {
-                'primaryRouter': {
-                    'datacenter': {
-                        'name': {'operation': '_= dal00'}},
-                },
+                'id': {
+                    'operation': 'orderBy',
+                    'options': [
+                           {'name': 'sort', 'value': ['ASC']}]},
                 'vlanNumber': {'operation': 5},
                 'name': {'operation': '_= primary-vlan'},
-            },
+                'primaryRouter': {
+                      'datacenter': {'name': {'operation': '_= dal00'}}}}
         }
         self.assert_called_with('SoftLayer_Account', 'getNetworkVlans',
                                 filter=_filter)