allow nodes that are not imported yet (fixes #1252)

spec/spec/utils/adopter.js

 import { mockAdopt, assignNewId, adopt } from '../../../src/utils/adopter.js'
 import { buildFixtures } from '../../helpers.js'
 import { globals, getWindow } from '../../../src/utils/window.js'
+import { svg } from '../../../src/modules/core/namespaces.js'
 
 const { any, createSpy, objectContaining } = jasmine
 
       // jasmine chucks on this when using the node directly
       expect(node.outerHTML).toBe(div.outerHTML)
     })
+
+    it('gracefully handles nodes that are not yet imported into the document', () => {
+      const otherDoc = globals.document.implementation.createDocument(
+        svg,
+        'svg'
+      )
+      const rect = otherDoc.createElementNS(svg, 'rect')
+
+      const node = nodeOrNew('rect', rect)
+
+      expect(node).toEqual(rect)
+    })
   })
 
   describe('register()/getClass()', () => {

src/utils/adopter.js

 
 export function nodeOrNew(name, node) {
   return node &&
-    node.ownerDocument &&
-    node instanceof node.ownerDocument.defaultView.Node
+    (node instanceof globals.window.Node ||
+      (node.ownerDocument &&
+        node instanceof node.ownerDocument.defaultView.Node))
     ? node
     : create(name)
 }