SPR-7257 - AbstractMarshaller incorrectly expects DOMResult to already have a node

org.springframework.oxm/src/main/java/org/springframework/oxm/support/AbstractMarshaller.java

 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -189,7 +189,21 @@ public abstract class AbstractMarshaller implements Marshaller, Unmarshaller {
 	 * @see #marshalDomNode(Object, org.w3c.dom.Node)
 	 */
 	protected void marshalDomResult(Object graph, DOMResult domResult) throws XmlMappingException {
-		Assert.notNull(domResult.getNode(), "DOMResult does not contain Node");
+		if (domResult.getNode() == null) {
+			try {
+				synchronized (this.documentBuilderFactoryMonitor) {
+					if (this.documentBuilderFactory == null) {
+						this.documentBuilderFactory = createDocumentBuilderFactory();
+					}
+				}
+				DocumentBuilder documentBuilder = createDocumentBuilder(this.documentBuilderFactory);
+				domResult.setNode(documentBuilder.newDocument());
+			}
+			catch (ParserConfigurationException ex) {
+				throw new UnmarshallingFailureException(
+						"Could not create document placeholder for DOMResult: " + ex.getMessage(), ex);
+			}
+		}
 		marshalDomNode(graph, domResult.getNode());
 	}
 

org.springframework.oxm/src/test/java/org/springframework/oxm/AbstractMarshallerTests.java

 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,8 +28,9 @@ import javax.xml.transform.dom.DOMResult;
 import javax.xml.transform.stax.StAXResult;
 import javax.xml.transform.stream.StreamResult;
 
-import static org.custommonkey.xmlunit.XMLAssert.assertXMLEqual;
+import static org.custommonkey.xmlunit.XMLAssert.*;
 import org.custommonkey.xmlunit.XMLUnit;
+import static org.junit.Assert.assertTrue;
 import org.junit.Before;
 import org.junit.Test;
 import org.w3c.dom.Attr;
@@ -86,6 +87,30 @@ public abstract class AbstractMarshallerTests {
 		assertXMLEqual("Marshaller writes invalid DOMResult", expected, result);
 	}
 
+	@Test
+	public void marshalEmptyDOMResult() throws Exception {
+		DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
+		documentBuilderFactory.setNamespaceAware(true);
+		DocumentBuilder builder = documentBuilderFactory.newDocumentBuilder();
+		DOMResult domResult = new DOMResult();
+		marshaller.marshal(flights, domResult);
+		assertTrue("DOMResult does not contain a Document", domResult.getNode() instanceof Document);
+		Document result = (Document) domResult.getNode();
+		Document expected = builder.newDocument();
+		Element flightsElement = expected.createElementNS("http://samples.springframework.org/flight", "tns:flights");
+		Attr namespace = expected.createAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:tns");
+		namespace.setNodeValue("http://samples.springframework.org/flight");
+		flightsElement.setAttributeNode(namespace);
+		expected.appendChild(flightsElement);
+		Element flightElement = expected.createElementNS("http://samples.springframework.org/flight", "tns:flight");
+		flightsElement.appendChild(flightElement);
+		Element numberElement = expected.createElementNS("http://samples.springframework.org/flight", "tns:number");
+		flightElement.appendChild(numberElement);
+		Text text = expected.createTextNode("42");
+		numberElement.appendChild(text);
+		assertXMLEqual("Marshaller writes invalid DOMResult", expected, result);
+	}
+
 	@Test
 	public void marshalStreamResultWriter() throws Exception {
 		StringWriter writer = new StringWriter();