fix(migrate): a shut-off VM whose NVRAM file is outside libvirt's directory is refused

Only a file in libvirt's NVRAM directory was copied; one elsewhere was
skipped without a word, and the VM started on the destination from the
firmware's template, its saved boot entries lost. Such a VM is now
refused before anything changes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Kk4h2TcUiaWmU5MUszYSea

vrtManager/instance.py

@@ -424,10 +424,16 @@ class wvmInstances(wvmConnect):
     def copy_nvram(self, conn):
         """Copies the UEFI variables file of the shut-off VM of conn (on the
         source) from libvirt's NVRAM directory there to the same path here,
-        unless both hosts share that directory. Returns the copy's name."""
+        unless both hosts share that directory. Returns the copy's name. A
+        file elsewhere is refused: it would stay behind, and the VM start
+        here from the firmware's template."""
         path = conn.get_nvram()
-        if not path or os.path.dirname(path) != NVRAM_DIR:
+        if not path:
             return None
+        if os.path.dirname(path) != NVRAM_DIR:
+            raise util.OperationError(gettext_noop(
+                "The NVRAM file %(path)s is not in libvirt's NVRAM directory %(dir)s and cannot be copied"),
+                path=path, dir=NVRAM_DIR)
         name = os.path.basename(path)
         with conn._nvram_pool() as source, self._nvram_pool() as target:
             vol = self._find_volume(source, name)

vrtManager/tests/test_migration.py

@@ -296,6 +296,12 @@ class NvramCopyTestCase(unittest.TestCase):
         copy.upload.assert_called_once_with(self.dest.wvm.newStream.return_value, 0, 4, 0)
         self.assertEqual(self.host.defined, ["<domain><name>vm</name></domain>"])
 
+    def test_a_file_outside_libvirt_s_directory_stops_the_move(self):
+        self.source.nvram = "/srv/vms/vm_VARS.fd"
+        with self.assertRaisesRegex(util.OperationError, "/srv/vms/vm_VARS.fd is not in libvirt's NVRAM directory"):
+            self.move()
+        self.assertEqual(self.host.defined, [])
+
     def test_a_failed_download_aborts_its_stream(self):
         stream = self.source.wvm.newStream.return_value
         stream.recvAll.side_effect = libvirt.libvirtError("download failed")