GH-79 fix nasty CrossReferenceTable error where subgroups were not pa…

…rsed.

core/core-awt/src/main/java/org/icepdf/core/pobjects/structure/CrossReferenceRoot.java

@@ -72,12 +72,10 @@ public DictionaryEntries getTrailerDictionary() {
 
     public PObject loadObject(ObjectLoader objectLoader, Reference reference, Name hint)
             throws ObjectStateException, CrossReferenceStateException, IOException {
-        if (crossReferences != null) {
-            PObject tmp;
-            for (CrossReference crossReference : crossReferences) {
-                tmp = crossReference.loadObject(objectLoader, reference, hint);
-                if (tmp != null) return tmp;
-            }
+        PObject tmp;
+        for (CrossReference crossReference : crossReferences) {
+            tmp = crossReference.loadObject(objectLoader, reference, hint);
+            if (tmp != null) return tmp;
         }
         return null;
     }

core/core-awt/src/main/java/org/icepdf/core/util/parser/object/Parser.java

@@ -186,20 +186,27 @@ public CrossReference getCrossReference(ByteBuffer byteBuffer, int starXref)
 
     private CrossReference parseCrossReferenceTable(DictionaryEntries dictionaryEntries, Lexer objectLexer, ByteBuffer byteBuffer,
                                                     int start, int end) throws IOException {
-        // allocate to a new buffer as the data is well defined.
+        // allocate to a new buffer as the data is well-defined.
         ByteBuffer xrefTableBuffer = ByteBufferUtil.copyObjectStreamSlice(byteBuffer, start, end);
         CrossReferenceTable crossReferenceTable = new CrossReferenceTable(library, dictionaryEntries);
         objectLexer.setByteBuffer(xrefTableBuffer);
-        int startObjectNumber = (Integer) objectLexer.nextToken();
-        int numberOfObjects = (Integer) objectLexer.nextToken();
-        for (int i = 0; i < numberOfObjects; i++) {
-            int offset = (Integer) objectLexer.nextToken();
-            int generation = (Integer) objectLexer.nextToken();
-            int state = (Integer) objectLexer.nextToken();
-            if (state == OperandNames.OP_n) {
-                crossReferenceTable.addEntry(new CrossReferenceUsedEntry(startObjectNumber + i, generation, offset));
+        // parse the sub groupings
+        while (true) {
+            Integer startObjectNumber = (Integer) objectLexer.nextToken();
+            // buffer end will result in a null token
+            if (startObjectNumber == null) break;
+            int numberOfObjects = (Integer) objectLexer.nextToken();
+            for (int i = 0; i < numberOfObjects; i++) {
+                int offset = (Integer) objectLexer.nextToken();
+                int generation = (Integer) objectLexer.nextToken();
+                int state = (Integer) objectLexer.nextToken();
+                if (state == OperandNames.OP_n) {
+                    crossReferenceTable.addEntry(
+                            new CrossReferenceUsedEntry(startObjectNumber + i, generation, offset));
+                }
             }
         }
+
         return crossReferenceTable;
     }