fix: preserve guest network identities and refresh session profiles

tests/test_runtime.py

@@ -88,6 +88,46 @@ class RuntimeTests(unittest.TestCase):
         except VMError:
             pass
 
+    def test_mac_persisted_distinct_and_stable_across_restarts(self):
+        self.runtime.add(Profile('other', network='bridge'))
+        other = self.runtime.profile('other')
+        guest = self.runtime.profile('guest')
+        self.assertIsNotNone(guest.mac)
+        self.assertNotEqual(guest.mac, other.mac)
+        octet = int(guest.mac.split(':')[0], 16)
+        self.assertEqual(octet & 3, 2)  # locally administered, unicast
+        def nic(profile, runtime):
+            return next(arg for arg in build_qemu_argv(profile, runtime.paths(profile.name))
+                        if arg.startswith('virtio-net-pci,'))
+        expected = nic(guest, self.runtime)
+        self.runtime.start('guest')
+        self.runtime.stop('guest', force=True)
+        self.runtime.start('guest')
+        self.runtime.stop('guest', force=True)
+        self.assertEqual(nic(self.runtime.profile('guest'), self.runtime), expected)
+        changed_runtime = Runtime(self.runtime.config, self.runtime.state, self.root / 'different-run')
+        self.assertEqual(nic(changed_runtime.profile('guest'), changed_runtime), expected)
+        self.runtime.media('guest', None)
+        self.assertEqual(self.runtime.profile('guest').mac, guest.mac)
+
+    def test_legacy_profiles_gain_stable_owner_specific_argv_mac(self):
+        file = self.runtime.config / 'legacy.toml'
+        save_profile(file, Profile('legacy', network='bridge'))
+        original = file.read_bytes()
+        legacy = self.runtime.profile('legacy')
+        self.assertIsNone(legacy.mac)
+        paths = self.runtime.paths('legacy')
+        def mac():
+            return next(arg for arg in build_qemu_argv(legacy, paths) if arg.startswith('virtio-net-pci,'))
+        with patch('os.getuid', return_value=1000):
+            first = mac()
+            self.assertEqual(mac(), first)
+            self.assertNotEqual(first, next(arg for arg in build_qemu_argv(
+                legacy, self.runtime.paths('other')) if arg.startswith('virtio-net-pci,')))
+        with patch('os.getuid', return_value=1001):
+            self.assertNotEqual(mac(), first)
+        self.assertEqual(file.read_bytes(), original)
+
     def test_disk_boot_omits_media_and_requests_display(self):
         profile = Profile('guest', width=1920, height=1080, refresh_millihz=144000,
                           graphics='software')
@@ -145,7 +185,7 @@ class RuntimeTests(unittest.TestCase):
         self.assertIn('disable-agent-file-xfer=on', spice)
         self.assertIn('run,,comma', spice)
         self.assertIn('virtio-blk-pci,drive=disk', argv)
-        self.assertIn('virtio-net-pci,netdev=net', argv)
+        self.assertTrue(any(arg.startswith('virtio-net-pci,netdev=net,mac=') for arg in argv))
         self.assertNotIn('-vnc', argv)
         self.assertNotIn('-virtfs', argv)