Fix several issues with PdfOutline processing

- support processing of incorrect hierarchy of outlines when merging
- process PdfNumber as page argument for outline destinations
- support copying of named destinations

DEVSIX-2517

Author: LodrKumquat

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

@@ -49,6 +49,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.pdf.layer.PdfOCProperties;
 import com.itextpdf.kernel.pdf.navigation.PdfDestination;
 import com.itextpdf.kernel.pdf.navigation.PdfExplicitDestination;
+import com.itextpdf.kernel.pdf.navigation.PdfNamedDestination;
 import com.itextpdf.kernel.pdf.navigation.PdfStringDestination;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -454,27 +455,32 @@ PdfDestination copyDestination(PdfObject dest, Map<PdfPage, PdfPage> page2page,
                     break;
                 }
             }
-        } else if (dest.isString()) {
+        } else if (dest.isString() || dest.isName()) {
             PdfNameTree destsTree = getNameTree(PdfName.Dests);
             Map<String, PdfObject> dests = destsTree.getNames();
-            String srcDestName = ((PdfString) dest).toUnicodeString();
+            String srcDestName = dest.isString() ? ((PdfString) dest).toUnicodeString() : ((PdfName) dest).getValue();
             PdfArray srcDestArray = (PdfArray) dests.get(srcDestName);
             if (srcDestArray != null) {
                 PdfObject pageObject = srcDestArray.get(0);
+                if (pageObject instanceof PdfNumber)
+                    pageObject = getDocument().getPage(((PdfNumber) pageObject).intValue() + 1).getPdfObject();
                 for (PdfPage oldPage : page2page.keySet()) {
                     if (oldPage.getPdfObject() == pageObject) {
                         d = new PdfStringDestination(srcDestName);
                         if (!isEqualSameNameDestExist(page2page, toDocument, srcDestName, srcDestArray, oldPage)) {
                             // in the copiedArray old page ref will be correctly replaced by the new page ref as this page is already copied
                             PdfArray copiedArray = (PdfArray) srcDestArray.copyTo(toDocument, false);
+                            // here we can safely replace first item of the array because array of NamedDestination or StringDestination
+                            // never refers to page in another document via PdfNumber, but should always refer to page within current document
+                            // via page object reference.
+                            copiedArray.set(0, page2page.get(oldPage).getPdfObject());
                             toDocument.addNamedDestination(srcDestName, copiedArray);
                         }
                         break;
                     }
                 }
             }
         }
-
         return d;
     }
 
@@ -495,6 +501,8 @@ private boolean isEqualSameNameDestExist(Map<PdfPage, PdfPage> page2page, PdfDoc
 
     private void addOutlineToPage(PdfOutline outline, Map<String, PdfObject> names) {
         PdfObject pageObj = outline.getDestination().getDestinationPage(names);
+        if (pageObj instanceof PdfNumber)
+            pageObj = getDocument().getPage(((PdfNumber) pageObj).intValue() + 1).getPdfObject();
         if (pageObj != null) {
             List<PdfOutline> outs = pagesWithOutlines.get(pageObj);
             if (outs == null) {
@@ -600,8 +608,6 @@ private void constructOutlines(PdfDictionary outlineRoot, Map<String, PdfObject>
 
             if (first != null) {
                 parentOutlineMap.put(current, currentOutline);
-            } else if (current == parent.getAsDictionary(PdfName.Last)) {
-                parentOutlineMap.remove(parent);
             }
             current = getNextOutline(first, next, parent);
 

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

@@ -1174,9 +1174,8 @@ public List<PdfPage> copyPagesTo(List<Integer> pagesToCopy, PdfDocument toDocume
             PdfPage page = getPage((int) pageNum);
             PdfPage newPage = page.copyTo(toDocument, copier);
             copiedPages.add(newPage);
-            if (!page2page.containsKey(page)) {
-                page2page.put(page, newPage);
-            }
+            page2page.put(page, newPage);
+
 
             if (lastCopiedPageNum >= pageNum) {
                 rangesOfPagesWithIncreasingNumbers.add(new HashMap<PdfPage, PdfPage>());

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

@@ -182,6 +182,38 @@ public void destCopyingTest05() throws IOException, InterruptedException {
         assertNull(new CompareTool().compareByContent(outFile, cmpFile, destinationFolder, "diff_"));
     }
 
+    @Test
+    public void destCopyingTest06() throws IOException, InterruptedException {
+        String srcFile = sourceFolder + "sourceWithNamedDestination.pdf";
+        String outFile = destinationFolder + "destCopyingTest06.pdf";
+        String cmpFile = sourceFolder + "cmp_destCopyingTest06.pdf";
+        PdfDocument srcDoc = new PdfDocument(new PdfReader(srcFile));
+
+        PdfDocument destDoc = new PdfDocument(new PdfWriter(outFile));
+        srcDoc.copyPagesTo(Arrays.asList(1, 2, 1), destDoc);
+        destDoc.close();
+
+        srcDoc.close();
+
+        assertNull(new CompareTool().compareByContent(outFile, cmpFile, destinationFolder, "diff_"));
+    }
+
+    @Test
+    public void destCopyingTest07() throws IOException, InterruptedException {
+        String srcFile = sourceFolder + "sourceStringDestWithPageNumber.pdf";
+        String outFile = destinationFolder + "destCopyingTest07.pdf";
+        String cmpFile = sourceFolder + "cmp_destCopyingTest07.pdf";
+        PdfDocument srcDoc = new PdfDocument(new PdfReader(srcFile));
+
+        PdfDocument destDoc = new PdfDocument(new PdfWriter(outFile));
+        srcDoc.copyPagesTo(Arrays.asList(1, 2, 1), destDoc);
+        destDoc.close();
+
+        srcDoc.close();
+
+        assertNull(new CompareTool().compareByContent(outFile, cmpFile, destinationFolder, "diff_"));
+    }
+
     @Test
     public void structureDestination01Test() throws IOException, InterruptedException {
         String srcFile = sourceFolder + "customRolesMappingPdf2.pdf";

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

@@ -268,4 +268,29 @@ public void mergeTableWithEmptyTdTest() throws IOException, InterruptedException
             Assert.fail(errorMessage);
         }
     }
+
+    @Test
+    @LogMessages(messages = {@LogMessage(messageTemplate = LogMessageConstant.NAME_ALREADY_EXISTS_IN_THE_NAME_TREE, count = 2)})
+    public void mergeOutlinesNamedDestinations() throws IOException, InterruptedException {
+        String filename = sourceFolder + "outlinesNamedDestinations.pdf";
+        String resultFile = destinationFolder + "mergeOutlinesNamedDestinations.pdf";
+
+        PdfReader reader = new PdfReader(filename);
+
+        PdfDocument sourceDoc = new PdfDocument(reader);
+        PdfDocument output = new PdfDocument(new PdfWriter(resultFile));
+        PdfMerger merger = new PdfMerger(output).setCloseSourceDocuments(false);
+        merger.merge(sourceDoc, 2, 3);
+        merger.merge(sourceDoc, 2, 3);
+        sourceDoc.close();
+        reader.close();
+        merger.close();
+        output.close();
+
+        CompareTool compareTool = new CompareTool();
+        String errorMessage = compareTool.compareByContent(resultFile, sourceFolder + "cmp_mergeOutlinesNamedDestinations.pdf", destinationFolder, "diff_");
+        if (errorMessage != null) {
+            Assert.fail(errorMessage);
+        }
+    }
 }