close #165: StackOverflowError in PDPageTree.getInheritableAttribute

src/main/java/org/sejda/sambox/pdmodel/PDPageTree.java

@@ -44,6 +44,7 @@
 import org.sejda.sambox.cos.COSName;
 import org.sejda.sambox.cos.COSNull;
 import org.sejda.sambox.cos.COSObjectable;
+import org.sejda.sambox.util.ObjectIdUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -136,6 +137,11 @@ public static <T extends COSBase> COSBase getInheritableAttribute(COSDictionary
      * @return COS value for the given key
      */
     public static COSBase getInheritableAttribute(COSDictionary node, COSName key)
+    {
+        return getInheritableAttribute(node, key, new HashSet<>());
+    }
+
+    public static COSBase getInheritableAttribute(COSDictionary node, COSName key, Set<String> visitedObjectIds)
     {
         COSBase value = node.getDictionaryObject(key);
         if (value != null)
@@ -154,7 +160,15 @@ public static COSBase getInheritableAttribute(COSDictionary node, COSName key)
 
         if (parent != null)
         {
-            return getInheritableAttribute(parent, key);
+            String objId = ObjectIdUtils.getObjectIdOf(node);
+            if(!objId.isBlank() && visitedObjectIds.contains(objId))
+            {
+                // prevent infinite recursion
+                return null;
+            }
+
+            visitedObjectIds.add(objId);
+            return getInheritableAttribute(parent, key, visitedObjectIds);
         }
 
         return null;

src/main/java/org/sejda/sambox/util/ObjectIdUtils.java

@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.sejda.sambox.util;
+
+import org.sejda.sambox.cos.COSObjectKey;
+import org.sejda.sambox.cos.COSObjectable;
+
+public class ObjectIdUtils {
+    private ObjectIdUtils() {}
+
+    public static String getObjectIdOf(COSObjectable obj)
+    {
+        try 
+        {
+            return getObjectIdOf(obj.getCOSObject().id().objectIdentifier);       
+        } 
+        catch (Exception ex)
+        {
+            return "";
+        }
+    }
+
+    public static String getObjectIdOf(COSObjectKey ident)
+    {
+        String gen = ident.generation() == 0 ? "" : ident.generation() + "";
+        return ident.objectNumber() + "R" + gen;
+    }
+}

src/test/java/org/sejda/sambox/pdmodel/PDPageTreeTest.java

@@ -19,16 +19,17 @@
 import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.CoreMatchers.endsWith;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.fail;
+import static org.junit.Assert.*;
 import static org.sejda.sambox.input.PDFParser.parse;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.file.Files;
 
 import org.junit.Test;
 import org.sejda.io.SeekableSources;
+import org.sejda.sambox.cos.COSBase;
+import org.sejda.sambox.cos.COSDictionary;
 import org.sejda.sambox.cos.COSName;
 import org.sejda.sambox.pdmodel.interactive.documentnavigation.outline.PDDocumentOutline;
 import org.sejda.sambox.pdmodel.interactive.documentnavigation.outline.PDOutlineItem;
@@ -336,4 +337,36 @@ public void noStackOverflowInCaseOfLoop() throws IOException
             doc.getPage(0);
         }
     }
+
+    @Test
+    public void getInheritableAttribute_recursive() throws IOException {
+        PDDocument doc = new PDDocument();
+        PDPage page = new PDPage();
+
+        doc.addPage(page);
+
+        COSDictionary dic1 = page.getCOSObject();
+        COSDictionary dic2 = new COSDictionary();
+        COSDictionary dic3 = new COSDictionary();
+
+        dic1.setItem(COSName.PARENT, dic2);
+        dic2.setItem(COSName.PARENT, dic3);
+        dic3.setItem(COSName.PARENT, dic1);
+
+        File tempFile = Files.createTempFile("sambox_getInheritableAttribute_recursive", ".pdf").toFile();
+        tempFile.deleteOnExit();
+
+        doc.save(tempFile.getAbsolutePath());
+
+        try (PDDocument doc2 = parse(SeekableSources.seekableSourceFrom(tempFile)))
+        {
+            PDPage p = doc.getPage(0);
+            COSBase value = PDPageTree.getInheritableAttribute(p.getCOSObject(), COSName.D);
+            assertNull(value);
+        }
+        finally 
+        {
+            tempFile.delete();
+        }
+    }
 }