Networkd tests: add bridge link properties to test

Test the "[Bridge]" section keys

```
[Bridge]
UnicastFlood=true
HairPin=true
UseBPDU=true
FastLeave=true
AllowPortToBeRoot=true
Cost=555
Priority=23
```

```
test_bridge_init (__main__.BridgeTest) ... ok
test_bridge_port_priority (__main__.BridgeTest) ... ok
test_bridge_port_priority_set_zero (__main__.BridgeTest)
It should be possible to set the bridge port priority to 0 ... ok
test_bridge_port_property (__main__.BridgeTest)
Test the "[Bridge]" section keys ... ok

```

1 files changed, 23 insertions, 0 deletions

diff --git a/test/networkd-test.py b/test/networkd-test.py
index 81b4d2ceb5..a51b3ebde9 100755
--- a/test/networkd-test.py
+++ b/test/networkd-test.py
@@ -205,6 +205,29 @@ Priority=0
         subprocess.check_call(['systemctl', 'restart', 'systemd-networkd'])
         self.assertEqual(self.read_attr('port2', 'brport/priority'), '0')
 
+    def test_bridge_port_property(self):
+        """Test the "[Bridge]" section keys"""
+        self.assertEqual(self.read_attr('port2', 'brport/priority'), '32')
+        self.write_network_dropin('port2.network', 'property', '''\
+[Bridge]
+UnicastFlood=true
+HairPin=true
+UseBPDU=true
+FastLeave=true
+AllowPortToBeRoot=true
+Cost=555
+Priority=23
+''')
+        subprocess.check_call(['systemctl', 'restart', 'systemd-networkd'])
+
+        self.assertEqual(self.read_attr('port2', 'brport/priority'), '23')
+        self.assertEqual(self.read_attr('port2', 'brport/hairpin_mode'), '1')
+        self.assertEqual(self.read_attr('port2', 'brport/path_cost'), '555')
+        self.assertEqual(self.read_attr('port2', 'brport/multicast_fast_leave'), '1')
+        self.assertEqual(self.read_attr('port2', 'brport/unicast_flood'), '1')
+        self.assertEqual(self.read_attr('port2', 'brport/bpdu_guard'), '1')
+        self.assertEqual(self.read_attr('port2', 'brport/root_block'), '1')
+
 class ClientTestBase(NetworkdTestingUtilities):
     """Provide common methods for testing networkd against servers."""