Add release notes wrt #3174

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -1343,3 +1343,8 @@ Eric Sirianni (sirianni@github)
 Tarekk Mohamed Abdalla (TarekkMA@github)
   * Contributed #3154: Add ArrayNode#set(int index, primitive_type value)
    (2.13.0)
+
+Morten Andersen-Gott (magott@github)
+  * Contributed #3174: DOM `Node` serialization omits the default namespace declaration
+   (2.13.0)
+

release-notes/VERSION-2.x

@@ -44,6 +44,8 @@ Project: jackson-databind
   serialization of ClassLoader)
 #3154: Add ArrayNode#set(int index, primitive_type value)
  (contributed by Tarekk Mohamed A)
+#3174: DOM `Node` serialization omits the default namespace declaration
+ (contributed by Morten A-G)
 - Fix to avoid problem with `BigDecimalNode`, scale of `Integer.MIN_VALUE` (see
   [dataformats-binary#264] for details)
 - Extend handling of `FAIL_ON_NULL_FOR_PRIMITIVES` to cover coercion from (Empty) String

src/main/java/com/fasterxml/jackson/databind/ext/DOMSerializer.java

@@ -1,56 +1,57 @@
 package com.fasterxml.jackson.databind.ext;
 
+import java.io.IOException;
+import java.io.StringWriter;
+
+import javax.xml.XMLConstants;
+import javax.xml.transform.*;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+
+import org.w3c.dom.Node;
+
 import com.fasterxml.jackson.core.JsonGenerator;
 import com.fasterxml.jackson.databind.JavaType;
 import com.fasterxml.jackson.databind.JsonMappingException;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.SerializerProvider;
 import com.fasterxml.jackson.databind.jsonFormatVisitors.JsonFormatVisitorWrapper;
 import com.fasterxml.jackson.databind.ser.std.StdSerializer;
-import org.w3c.dom.Node;
 
-import javax.xml.XMLConstants;
-import javax.xml.transform.*;
-import javax.xml.transform.dom.DOMSource;
-import javax.xml.transform.stream.StreamResult;
-import java.io.IOException;
-import java.io.StringWriter;
 @SuppressWarnings("serial")
 public class DOMSerializer extends StdSerializer<Node>
 {
-
-    private final TransformerFactory transformerFactory;
+    protected final TransformerFactory transformerFactory;
 
     public DOMSerializer() {
         super(Node.class);
         try {
             transformerFactory = TransformerFactory.newInstance();
             transformerFactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
         } catch (Exception e) {
-            throw new IllegalStateException("Could not instantiate TransformerFactory: "+e.getMessage(), e);
+            throw new IllegalStateException("Could not instantiate `TransformerFactory`: "+e.getMessage(), e);
         }
     }
-    
+
     @Override
-    public void serialize(Node value, JsonGenerator jgen, SerializerProvider provider)
+    public void serialize(Node value, JsonGenerator g, SerializerProvider provider)
         throws IOException
     {
         try {
             Transformer transformer = transformerFactory.newTransformer();
             transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
             transformer.setOutputProperty(OutputKeys.INDENT, "no");
             StreamResult result = new StreamResult(new StringWriter());
-            DOMSource source = new DOMSource(value);
-            transformer.transform(source, result);
-            jgen.writeString(result.getWriter().toString());
+            transformer.transform(new DOMSource(value), result);
+            g.writeString(result.getWriter().toString());
         } catch (TransformerConfigurationException e) {
-            throw new IllegalStateException("Could not create XML Transformer: "+e.getMessage(), e);
+            throw new IllegalStateException("Could not create XML Transformer for writing DOM `Node` value: "+e.getMessage(), e);
         } catch (TransformerException e) {
-            provider.reportMappingProblem(e,"XML Transformation failed: %s", e.getMessage());
+            provider.reportMappingProblem(e, "DOM `Node` value serialization failed: %s", e.getMessage());
         }
     }
 
-	@Override
+    @Override
     public JsonNode getSchema(SerializerProvider provider, java.lang.reflect.Type typeHint) {
         // Well... it is serialized as String
         return createSchemaNode("string", true);