Add tests to the setModified method

DEVSIX-3430

Author: EvgenyB1001

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

@@ -52,6 +52,8 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.pdf.xobject.PdfFormXObject;
 import com.itextpdf.test.ExtendedITextTest;
 import com.itextpdf.test.annotations.type.IntegrationTest;
+
+import java.util.ArrayList;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -60,6 +62,7 @@ This file is part of the iText (R) project.
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.util.Set;
 import java.util.Map;
 
 @Category(IntegrationTest.class)
@@ -147,4 +150,65 @@ public void annotationAppearanceTest() throws IOException {
         pdfDocument.close();
         Assert.assertEquals(1, objs.size());
     }
+
+    @Test
+    public void setModifiedFlagTest() throws IOException {
+        testSetModified(false);
+    }
+
+    @Test
+    public void setModifiedFlagAppendModeTest() throws IOException {
+        testSetModified(true);
+    }
+
+    private static void testSetModified(boolean isAppendMode) throws IOException {
+        String[] expectedKeys = {
+                "new_key1",
+                "new_key2",
+                "new_key3",
+        };
+
+        ByteArrayOutputStream sourceFile = createDocumentInMemory();
+        ByteArrayOutputStream modifiedFile = new ByteArrayOutputStream();
+        PdfReader reader = new PdfReader(new ByteArrayInputStream(sourceFile.toByteArray()));
+        PdfDocument pdfDoc = isAppendMode
+                ? new PdfDocument(reader, new PdfWriter(modifiedFile), new StampingProperties().useAppendMode())
+                : new PdfDocument(reader, new PdfWriter(modifiedFile));
+        PdfNameTree nameTree = pdfDoc.getCatalog().getNameTree(PdfName.Dests);
+        Map<String, PdfObject> names = nameTree.getNames();
+        ArrayList<String> keys = new ArrayList<>(names.keySet());
+
+        for (int i = 0; i < keys.size(); i++) {
+            names.put(expectedKeys[i], names.get(keys.get(i)));
+            names.remove(keys.get(i));
+        }
+
+        nameTree.setModified();
+
+        pdfDoc.close();
+
+        reader = new PdfReader(new ByteArrayInputStream(modifiedFile.toByteArray()));
+        pdfDoc = new PdfDocument(reader);
+        nameTree = pdfDoc.getCatalog().getNameTree(PdfName.Dests);
+        Set<String> actualKeys = nameTree.getNames().keySet();
+
+        Assert.assertArrayEquals(expectedKeys, actualKeys.toArray());
+    }
+
+    private static ByteArrayOutputStream createDocumentInMemory() {
+        ByteArrayOutputStream boas = new ByteArrayOutputStream();
+        PdfDocument pdfDoc = new PdfDocument(new PdfWriter(boas));
+
+        pdfDoc.addNewPage();
+        pdfDoc.getCatalog().getNameTree(PdfName.Dests).addEntry("key1",
+                new PdfArray(new float[] {0, 0, 0, 0}));
+        pdfDoc.getCatalog().getNameTree(PdfName.Dests).addEntry("key2",
+                new PdfArray(new float[] {1, 1, 1, 1}));
+        pdfDoc.getCatalog().getNameTree(PdfName.Dests).addEntry("key3",
+                new PdfArray(new float[] {2, 2, 2, 2}));
+
+        pdfDoc.close();
+
+        return boas;
+    }
 }