Check copied outline's destination on null reference. Add a test.

DEVSIX-1660

Author: ars18wrw

kernel/src/main/java/com/itextpdf/kernel/pdf/PdfDocument.java

@@ -2077,8 +2077,11 @@ private void cloneOutlines(Set<PdfOutline> outlinesToCopy, PdfOutline newParent,
         }
         for (PdfOutline outline : oldParent.getAllChildren()) {
             if (outlinesToCopy.contains(outline)) {
-                PdfObject destObjToCopy = outline.getDestination().getPdfObject();
-                PdfDestination copiedDest = getCatalog().copyDestination(destObjToCopy, page2page, toDocument);
+                PdfDestination copiedDest = null;
+                if (null != outline.getDestination()) {
+                    PdfObject destObjToCopy = outline.getDestination().getPdfObject();
+                    copiedDest = getCatalog().copyDestination(destObjToCopy, page2page, toDocument);
+                }
                 PdfOutline child = newParent.addOutline(outline.getTitle());
                 if (copiedDest != null) {
                     child.addDestination(copiedDest);

kernel/src/test/java/com/itextpdf/kernel/utils/PdfMergerTest.java

@@ -107,6 +107,27 @@ public void mergeDocumentTest01() throws IOException, InterruptedException {
         }
     }
 
+    @Test
+    @LogMessages(messages = {
+            @LogMessage(messageTemplate = LogMessageConstant.SOURCE_DOCUMENT_HAS_ACROFORM_DICTIONARY)
+    })
+    public void mergeDocumentOutlinesWithNullDestinationTest01() throws IOException, InterruptedException {
+        String resultFile = destinationFolder + "mergeDocumentOutlinesWithNullDestinationTest01.pdf";
+        String filename = sourceFolder + "null_dest_outline.pdf";
+        PdfDocument sourceDocument = new PdfDocument(new PdfReader(filename));
+
+        PdfMerger resultDocument = new PdfMerger(new PdfDocument(new PdfWriter(resultFile)));
+        resultDocument.merge(sourceDocument, 1, 1);
+        resultDocument.close();
+        sourceDocument.close();
+
+        CompareTool compareTool = new CompareTool();
+        String errorMessage = compareTool.compareByContent(resultFile, sourceFolder + "cmp_mergeDocumentOutlinesWithNullDestinationTest01.pdf", destinationFolder, "diff_");
+        if (errorMessage != null) {
+            Assert.fail(errorMessage);
+        }
+    }
+
     @Test
     public void mergeDocumentTest02() throws IOException, InterruptedException {
         String filename = sourceFolder + "doc1.pdf";