test-network: add test case for MACAddress=none in .netdev and MACAddressPolicy=none in .link

Prompted by #30813.

test/test-network/conf/26-bridge-mac-master.network

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+[Match]
+Name=bridge99
+
+[Network]
+IPv6AcceptRA=false

test/test-network/conf/26-bridge-mac-slave.network

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+[Match]
+Name=dummy98
+
+[Network]
+IPv6AcceptRA=no
+Bridge=bridge99

test/test-network/conf/26-bridge-mac.link

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+[Match]
+OriginalName=bridge99
+
+[Link]
+MACAddressPolicy=none

test/test-network/conf/26-bridge-mac.netdev

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+[NetDev]
+Name=bridge99
+Kind=bridge
+MACAddress=none

test/test-network/systemd-networkd-tests.py

@@ -4540,6 +4540,20 @@ class NetworkdBridgeTests(unittest.TestCase, Utilities):
     def tearDown(self):
         tear_down_common()
 
+    def test_bridge_mac_none(self):
+        copy_network_unit('12-dummy-mac.netdev', '26-bridge-mac-slave.network',
+                          '26-bridge-mac.netdev', '26-bridge-mac-master.network', '26-bridge-mac.link')
+        start_networkd()
+        self.wait_online(['dummy98:enslaved', 'bridge99:degraded'])
+
+        output = check_output('ip link show dev dummy98')
+        print(output)
+        self.assertIn('link/ether 12:34:56:78:9a:01', output)
+
+        output = check_output('ip link show dev bridge99')
+        print(output)
+        self.assertIn('link/ether 12:34:56:78:9a:01', output)
+
     def test_bridge_vlan(self):
         copy_network_unit('11-dummy.netdev', '26-bridge-vlan-slave.network',
                           '26-bridge.netdev', '26-bridge-vlan-master.network',