fix #646. "Document already has a root node" while using Builder in J…

…Ruby

CHANGELOG.rdoc

@@ -34,6 +34,7 @@
   * Nokogiri.parse() does not mistake a non-HTML document like a RSS
     document as HTML document. #932 (Thanks, Yamagishi Kazutoshi!)
   * XSD validation crashes in Java version. #373
+  * (JRuby) Document already has a root node error while using Builder. #646
 
 
 === 1.6.0 / 2013-06-08

ext/java/nokogiri/XmlNode.java

@@ -88,6 +88,7 @@
  */
 @JRubyClass(name="Nokogiri::XML::Node")
 public class XmlNode extends RubyObject {
+    protected static final String TEXT_WRAPPER_NAME = "nokogiri_text_wrapper";
 
     /** The underlying Node object. */
     protected Node node;
@@ -1498,14 +1499,18 @@ protected Node[] adoptAsChild(ThreadContext context, Node parent,
          * text node as the root element.  Java (and XML spec?) does
          * not.  So we wrap the text node in an element.
          */
-        if (parent.getNodeType() == Node.DOCUMENT_NODE &&
-            otherNode.getNodeType() == Node.TEXT_NODE) {
-            Element e = ((Document)parent).createElement("nokogiri_text_wrapper");
-            e.appendChild(otherNode);
-            otherNode = e;
-        }
-        addNamespaceURIIfNeeded(otherNode);
-        parent.appendChild(otherNode);
+        if (parent.getNodeType() == Node.DOCUMENT_NODE && otherNode.getNodeType() == Node.TEXT_NODE) {
+          Element e = (Element) parent.getFirstChild();
+          if (e == null || !e.getNodeName().equals(TEXT_WRAPPER_NAME)) {
+            e = ((Document)parent).createElement(TEXT_WRAPPER_NAME);
+            adoptAsChild(context, parent, e);
+          }
+          e.appendChild(otherNode);
+          otherNode = e;
+        } else {
+          addNamespaceURIIfNeeded(otherNode);
+          parent.appendChild(otherNode);
+        }
         Node[] nodes = new Node[1];
         nodes[0] = otherNode;
         return nodes;

lib/nokogiri/xml/builder.rb

@@ -380,7 +380,7 @@ def method_missing method, *args, &block # :nodoc:
       ###
       # Insert +node+ as a child of the current Node
       def insert(node, &block)
-        node.parent = @parent
+        node = @parent.add_child(node)
         if block_given?
           old_parent = @parent
           @parent    = node

lib/nokogiri/xml/document.rb

@@ -233,7 +233,7 @@ def fragment tags = nil
       undef_method :namespace_definitions, :line, :add_namespace
 
       def add_child node_or_tags
-        raise "Document already has a root node" if root
+        raise "Document already has a root node" if root && root.name != 'nokogiri_text_wrapper'
         node_or_tags = coerce(node_or_tags)
         if node_or_tags.is_a?(XML::NodeSet)
           raise "Document cannot have multiple root nodes" if node_or_tags.size > 1

test/xml/test_builder.rb

@@ -13,6 +13,15 @@ def test_attribute_sensitivity
         assert_equal 'world', doc.root['abcDef']
       end
 
+      def test_builder_multiple_nodes
+        builder = Nokogiri::XML::Builder.new do |xml|
+          0.upto(10) do
+            xml.text "test"
+          end
+        end
+      end
+
+
       def test_builder_with_utf8_text
         text = "test ﺵ "
         doc = Nokogiri::XML::Builder.new(:encoding => "UTF-8") { |xml| xml.test text }.doc