Polishing contribution

See gh-1607

spring-oxm/src/main/java/org/springframework/oxm/xstream/XStreamMarshaller.java

@@ -56,6 +56,7 @@ import com.thoughtworks.xstream.io.xml.DomReader;
 import com.thoughtworks.xstream.io.xml.DomWriter;
 import com.thoughtworks.xstream.io.xml.QNameMap;
 import com.thoughtworks.xstream.io.xml.SaxWriter;
+import com.thoughtworks.xstream.io.xml.StaxDriver;
 import com.thoughtworks.xstream.io.xml.StaxReader;
 import com.thoughtworks.xstream.io.xml.StaxWriter;
 import com.thoughtworks.xstream.io.xml.XmlFriendlyNameCoder;
@@ -696,13 +697,14 @@ public class XStreamMarshaller extends AbstractMarshaller implements BeanClassLo
 	@Override
 	protected void marshalXmlStreamWriter(Object graph, XMLStreamWriter streamWriter) throws XmlMappingException {
 		try {
-			final StaxWriter writer;
-			if( streamDriver instanceof StaxDriver){
-				writer = ((StaxDriver)streamDriver).createStaxWriter(streamWriter);
-			}else{
-				writer =  new StaxWriter( new QNameMap(),streamWriter, this.nameCoder);
+			StaxWriter writer;
+			if (this.streamDriver instanceof StaxDriver) {
+				writer = ((StaxDriver) this.streamDriver).createStaxWriter(streamWriter);
 			}
-			doMarshal(graph,writer, null);
+			else {
+				writer = new StaxWriter(new QNameMap(), streamWriter, this.nameCoder);
+			}
+			doMarshal(graph, writer, null);
 		}
 		catch (XMLStreamException ex) {
 			throw convertXStreamException(ex, true);

spring-oxm/src/test/java/org/springframework/oxm/xstream/XStreamMarshallerTests.java

@@ -43,6 +43,8 @@ import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
 import com.thoughtworks.xstream.io.json.JettisonMappedXmlDriver;
 import com.thoughtworks.xstream.io.json.JsonHierarchicalStreamDriver;
 import com.thoughtworks.xstream.io.json.JsonWriter;
+import com.thoughtworks.xstream.io.xml.QNameMap;
+import com.thoughtworks.xstream.io.xml.StaxDriver;
 import com.thoughtworks.xstream.security.AnyTypePermission;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -176,6 +178,23 @@ class XStreamMarshallerTests {
 		assertThat(XmlContent.from(writer)).isSimilarTo(EXPECTED_STRING);
 	}
 
+	@Test
+	void marshalStaxResultXMLStreamWriterDefaultNamespace() throws Exception {
+		QNameMap map = new QNameMap();
+		map.setDefaultNamespace("https://example.com");
+		map.setDefaultPrefix("spr");
+		StaxDriver driver = new StaxDriver(map);
+		marshaller.setStreamDriver(driver);
+
+		XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();
+		StringWriter writer = new StringWriter();
+		XMLStreamWriter streamWriter = outputFactory.createXMLStreamWriter(writer);
+		Result result = StaxUtils.createStaxResult(streamWriter);
+		marshaller.marshal(flight, result);
+		assertThat(XmlContent.from(writer)).isSimilarTo(
+				"<spr:flight xmlns:spr=\"https://example.com\"><spr:flightNumber>42</spr:flightNumber></spr:flight>");
+	}
+
 	@Test
 	void marshalStaxResultXMLEventWriter() throws Exception {
 		XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();