committing fix as per discussion here, https://markmail.org/message/x5e5nreyj7eruyly on j-dev list

git-svn-id: https://svn.apache.org/repos/asf/xerces/java/trunk@1829683 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/org/apache/xerces/dom/NamedNodeMapImpl.java b/src/org/apache/xerces/dom/NamedNodeMapImpl.java
index 325b5fc..23a9f22 100644
--- a/src/org/apache/xerces/dom/NamedNodeMapImpl.java
+++ b/src/org/apache/xerces/dom/NamedNodeMapImpl.java
@@ -605,7 +605,8 @@
         throws IOException, ClassNotFoundException {
         in.defaultReadObject();
         if (nodes != null) {
-            nodes = new ArrayList(nodes);
+            // cast to Vector is required
+            nodes = new ArrayList((Vector)nodes);
         }
     }