PDFBOX-6025: avoid ClassCastException

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1926693 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

pdfbox/src/main/java/org/apache/pdfbox/pdmodel/PDStructureElementNameTreeNode.java

@@ -51,6 +51,10 @@ public PDStructureElementNameTreeNode( COSDictionary dic )
     @Override
     protected PDStructureElement convertCOSToPD( COSBase base ) throws IOException
     {
+        if (!(base instanceof COSDictionary))
+        {
+            throw new IOException("dictionary expected here, but got " + base);
+        }
         return new PDStructureElement((COSDictionary)base);
     }
 

pdfbox/src/test/java/org/apache/pdfbox/pdmodel/common/PDIntegerNameTreeNode.java

@@ -50,6 +50,10 @@ public PDIntegerNameTreeNode(COSDictionary dic)
     @Override
     protected COSInteger convertCOSToPD(COSBase base) throws IOException
     {
+        if (!(base instanceof COSInteger))
+        {
+            throw new IOException("integer expected here, but got " + base);
+        }
         return (COSInteger)base;
     }