Do not return DocumentFragment from AppendChild() etc. Fixed bug #666249.

mcs/class/System.XML/System.Xml/XmlNode.cs

@@ -540,10 +540,13 @@ namespace System.Xml
 
 			if (newChild.NodeType == XmlNodeType.DocumentFragment) {
 				// This recursively invokes events. (It is compatible with MS implementation.)
-				while (newChild.FirstChild != null)
-					this.InsertBefore (newChild.FirstChild, refChild);
-			}
-			else {
+				XmlNode ret = null;
+				while (newChild.FirstChild != null) {
+					var c = this.InsertBefore (newChild.FirstChild, refChild);
+					ret = ret ?? c;
+				}
+				return ret;
+			} else {
 				XmlLinkedNode newLinkedChild = (XmlLinkedNode) newChild;
 				newLinkedChild.parentNode = this;
 
@@ -585,8 +588,8 @@ namespace System.Xml
 
 				if (raiseEvent)
 					ownerDoc.onNodeInserted (newChild, newChild.ParentNode);
+				return newChild;
 			}
-			return newChild;
 		}
 
 		private void CheckNodeInsertion (XmlNode newChild, XmlNode refChild)

mcs/class/System.XML/Test/System.Xml/XmlDocumentFragmentTests.cs

@@ -57,11 +57,12 @@ namespace MonoTests.System.Xml
 			fragment.AppendChild (document.CreateElement ("div"));
 
 			// appending fragment to element
-			body.AppendChild (fragment);
+			XmlNode ret = body.AppendChild (fragment);
 			Assert.IsNotNull (body.FirstChild, "#AppendFragmentToElement.Exist");
 			Assert.AreEqual (XmlNodeType.Element, body.FirstChild.NodeType, "#AppendFragmentToElement.ChildIsElement");
 			Assert.AreEqual ("p", body.FirstChild.Name, "#AppendFragmentToElement.FirstChild");
 			Assert.AreEqual ("div", body.LastChild.Name, "#AppendFragmentToElement.LastChild");
+			Assert.AreEqual ("p", ret.LocalName, "#AppendFragmentToElement.ReturnValue");
 		}
 
 		[Test]