Add tests demonstrating problems with annotation relationship incorrectly transferred during copying

If annotations refer to other annotations with Popup or IRT keys,
this relationship is not correctly transferred at the moment and the
result is annotation on one page referring to an annotation on
another page, which for IRT key for example is forbidden by the
specification

DEVSIX-3585

Autoported commit.
Original commit hash: [c3e97d52a]

Author: Snipx

itext.tests/itext.kernel.tests/itext/kernel/pdf/copy/PdfAnnotationCopyingTest.cs

@@ -0,0 +1,130 @@
+/*
+This file is part of the iText (R) project.
+Copyright (c) 1998-2019 iText Group NV
+Authors: iText Software.
+
+This program is offered under a commercial and under the AGPL license.
+For commercial licensing, contact us at https://itextpdf.com/sales.  For AGPL licensing, see below.
+
+AGPL licensing:
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+using System;
+using NUnit.Framework;
+using iText.IO.Util;
+using iText.Kernel.Pdf;
+using iText.Kernel.Pdf.Annot;
+using iText.Test;
+
+namespace iText.Kernel.Pdf.Copy {
+    public class PdfAnnotationCopyingTest : ExtendedITextTest {
+        public static readonly String destinationFolder = NUnit.Framework.TestContext.CurrentContext.TestDirectory
+             + "/test/itext/kernel/pdf/PdfAnnotationCopyingTest/";
+
+        public static readonly String sourceFolder = iText.Test.TestUtil.GetParentProjectDirectory(NUnit.Framework.TestContext
+            .CurrentContext.TestDirectory) + "/resources/itext/kernel/pdf/PdfAnnotationCopyingTest/";
+
+        [NUnit.Framework.OneTimeSetUp]
+        public static void BeforeClass() {
+            CreateOrClearDestinationFolder(destinationFolder);
+        }
+
+        [NUnit.Framework.Test]
+        public virtual void TestCopyingPageWithAnnotationContainingPopupKey() {
+            NUnit.Framework.Assert.That(() =>  {
+                // TODO remove expected exception and thus enable assertions when DEVSIX-3585 is implemented
+                String inFilePath = sourceFolder + "annotation-with-popup.pdf";
+                String outFilePath = destinationFolder + "copy-annotation-with-popup.pdf";
+                PdfDocument originalDocument = new PdfDocument(new PdfReader(inFilePath));
+                PdfDocument outDocument = new PdfDocument(new PdfWriter(outFilePath));
+                originalDocument.CopyPagesTo(1, 1, outDocument);
+                // During the second copy call we have to rebuild/preserve all the annotation relationship (Popup in this case),
+                // so that we don't end up with annotation on one page referring to an annotation on another page as its popup
+                // or as its parent
+                originalDocument.CopyPagesTo(1, 1, outDocument);
+                originalDocument.Close();
+                outDocument.Close();
+                outDocument = new PdfDocument(new PdfReader(outFilePath));
+                for (int pageNum = 1; pageNum <= outDocument.GetNumberOfPages(); pageNum++) {
+                    PdfPage page = outDocument.GetPage(pageNum);
+                    NUnit.Framework.Assert.AreEqual(2, page.GetAnnotsSize());
+                    NUnit.Framework.Assert.AreEqual(2, page.GetAnnotations().Count);
+                    bool foundMarkupAnnotation = false;
+                    foreach (PdfAnnotation annotation in page.GetAnnotations()) {
+                        PdfDictionary annotationPageDict = annotation.GetPageObject();
+                        if (annotationPageDict != null) {
+                            NUnit.Framework.Assert.AreSame(page.GetPdfObject(), annotationPageDict);
+                        }
+                        if (annotation is PdfMarkupAnnotation) {
+                            foundMarkupAnnotation = true;
+                            PdfPopupAnnotation popup = ((PdfMarkupAnnotation)annotation).GetPopup();
+                            NUnit.Framework.Assert.IsTrue(page.ContainsAnnotation(popup), MessageFormatUtil.Format("Popup reference must point to annotation present on the same page (# {0})"
+                                , pageNum));
+                            PdfDictionary parentAnnotation = popup.GetParentObject();
+                            NUnit.Framework.Assert.AreSame(annotation.GetPdfObject(), parentAnnotation, "Popup annotation parent must point to the annotation that specified it as Popup"
+                                );
+                        }
+                    }
+                    NUnit.Framework.Assert.IsTrue(foundMarkupAnnotation, "Markup annotation expected to be present but not found"
+                        );
+                }
+                outDocument.Close();
+            }
+            , NUnit.Framework.Throws.InstanceOf<AssertionException>())
+;
+        }
+
+        [NUnit.Framework.Test]
+        public virtual void TestCopyingPageWithAnnotationContainingIrtKey() {
+            NUnit.Framework.Assert.That(() =>  {
+                // TODO remove expected exception and thus enable assertions when DEVSIX-3585 is implemented
+                String inFilePath = sourceFolder + "annotation-with-irt.pdf";
+                String outFilePath = destinationFolder + "copy-annotation-with-irt.pdf";
+                PdfDocument originalDocument = new PdfDocument(new PdfReader(inFilePath));
+                PdfDocument outDocument = new PdfDocument(new PdfWriter(outFilePath));
+                originalDocument.CopyPagesTo(1, 1, outDocument);
+                // During the second copy call we have to rebuild/preserve all the annotation relationship (IRT in this case),
+                // so that we don't end up with annotation on one page referring to an annotation on another page as its IRT
+                // or as its parent
+                originalDocument.CopyPagesTo(1, 1, outDocument);
+                originalDocument.Close();
+                outDocument.Close();
+                outDocument = new PdfDocument(new PdfReader(outFilePath));
+                for (int pageNum = 1; pageNum <= outDocument.GetNumberOfPages(); pageNum++) {
+                    PdfPage page = outDocument.GetPage(pageNum);
+                    NUnit.Framework.Assert.AreEqual(4, page.GetAnnotsSize());
+                    NUnit.Framework.Assert.AreEqual(4, page.GetAnnotations().Count);
+                    bool foundMarkupAnnotation = false;
+                    foreach (PdfAnnotation annotation in page.GetAnnotations()) {
+                        PdfDictionary annotationPageDict = annotation.GetPageObject();
+                        if (annotationPageDict != null) {
+                            NUnit.Framework.Assert.AreSame(page.GetPdfObject(), annotationPageDict);
+                        }
+                        if (annotation is PdfMarkupAnnotation) {
+                            foundMarkupAnnotation = true;
+                            PdfDictionary inReplyTo = ((PdfMarkupAnnotation)annotation).GetInReplyToObject();
+                            NUnit.Framework.Assert.IsTrue(page.ContainsAnnotation(PdfAnnotation.MakeAnnotation(inReplyTo)), "IRT reference must point to annotation present on the same page"
+                                );
+                        }
+                    }
+                    NUnit.Framework.Assert.IsTrue(foundMarkupAnnotation, "Markup annotation expected to be present but not found"
+                        );
+                }
+                outDocument.Close();
+            }
+            , NUnit.Framework.Throws.InstanceOf<AssertionException>())
+;
+        }
+    }
+}

itext.tests/itext.kernel.tests/resources/itext/kernel/pdf/PdfAnnotationCopyingTest/annotation-with-irt.pdf

@@ -1363,7 +1363,7 @@ public virtual iText.Kernel.Pdf.Annot.PdfAnnotation SetTitle(PdfString title) {
         /// <returns>
         /// 
         /// <see cref="iText.Kernel.Pdf.PdfString"/>
-        /// which value is an annotation title or null if it isn't specifed.
+        /// which value is an annotation title or null if it isn't specified.
         /// </returns>
         public virtual PdfString GetTitle() {
             return GetPdfObject().GetAsString(PdfName.T);

itext.tests/itext.kernel.tests/resources/itext/kernel/pdf/PdfAnnotationCopyingTest/annotation-with-popup.pdf

@@ -1 +1 @@
-eb43d782a1bda5142eee6cc0ab1c5237b864d98d
+c3e97d52af4a38b3c447deb4aced473eea0fb56a