Do not copy destination if it is null

DEVSIX-3633

Author: ars18wrw

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

@@ -562,6 +562,9 @@ void addRootOutline(PdfOutline outline) {
     }
 
     PdfDestination copyDestination(PdfObject dest, Map<PdfPage, PdfPage> page2page, PdfDocument toDocument) {
+        if (null == dest) {
+            return null;
+        }
         PdfDestination d = null;
         if (dest.isArray()) {
             PdfObject pageObject = ((PdfArray) dest).get(0);

kernel/src/test/java/com/itextpdf/kernel/pdf/PdfDestinationTest.java

@@ -60,6 +60,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.test.annotations.type.IntegrationTest;
 
 import java.io.ByteArrayOutputStream;
+import java.util.HashMap;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -407,4 +408,19 @@ public void remoteGoToNotValidExplicitDestinationTest() throws IOException, Inte
 
         assertNull(new CompareTool().compareByContent(outFile, cmpFile, destinationFolder, "diff_"));
     }
+
+    @Test
+    public void copyNullDestination() throws IOException {
+        try (
+                ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                PdfDocument pdfDocument = new PdfDocument(new PdfWriter(baos))) {
+            pdfDocument.addNewPage();
+
+            PdfDestination copiedDestination = pdfDocument.getCatalog()
+                    .copyDestination(null, new HashMap<PdfPage, PdfPage>(), pdfDocument);
+
+            // We expect null to be returned if the destination to be copied is null
+            Assert.assertNull(copiedDestination);
+        }
+    }
 }