Fix incorrect /Size entry of trailer for generated in append mode documents

Author: yulian-gaponenko

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

@@ -160,7 +160,7 @@ protected void setCapacity(int capacity) {
     /**
      * Writes cross reference table and trailer to PDF.
      *
-     * @throws java.io.IOException
+     * @throws IOException
      * @throws PdfException
      */
     protected void writeXrefTableAndTrailer(PdfDocument document, PdfObject fileId, PdfObject crypto) throws IOException {
@@ -177,6 +177,19 @@ protected void writeXrefTableAndTrailer(PdfDocument document, PdfObject fileId,
         }
         freeReferences.clear();
 
+
+        for (int i = count; i > 0; --i) {
+            PdfIndirectReference lastRef = xref[i];
+            if (lastRef == null
+                    || (lastRef.isFree() && lastRef.getGenNumber() == 0)
+                    || (!lastRef.checkState(PdfObject.FLUSHED)
+                            && !(document.properties.appendMode && !lastRef.checkState(PdfObject.MODIFIED)))) {
+                --count;
+            } else {
+                break;
+            }
+        }
+
         List<Integer> sections = new ArrayList<>();
         int first = 0;
         int len = 1;
@@ -218,7 +231,6 @@ protected void writeXrefTableAndTrailer(PdfDocument document, PdfObject fileId,
             return;
         }
 
-        int size = sections.get(sections.size() - 2) + sections.get(sections.size() - 1);
         long startxref = writer.getCurrentPos();
         if (writer.isFullCompression()) {
             PdfStream xrefStream = new PdfStream().makeIndirect(document);
@@ -227,7 +239,7 @@ protected void writeXrefTableAndTrailer(PdfDocument document, PdfObject fileId,
             xrefStream.put(PdfName.ID, fileId);
             if (crypto != null)
                 xrefStream.put(PdfName.Encrypt, crypto);
-            xrefStream.put(PdfName.Size, new PdfNumber(size));
+            xrefStream.put(PdfName.Size, new PdfNumber(this.size()));
             xrefStream.put(PdfName.W, new PdfArray(new ArrayList<PdfObject>() {{
                 add(new PdfNumber(1));
                 add(new PdfNumber(4));
@@ -295,7 +307,7 @@ protected void writeXrefTableAndTrailer(PdfDocument document, PdfObject fileId,
             trailer.remove(PdfName.Index);
             trailer.remove(PdfName.Type);
             trailer.remove(PdfName.Length);
-            trailer.put(PdfName.Size, new PdfNumber(size));
+            trailer.put(PdfName.Size, new PdfNumber(this.size()));
             trailer.put(PdfName.ID, fileId);
             if (crypto != null)
                 trailer.put(PdfName.Encrypt, crypto);

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

@@ -204,7 +204,7 @@ public void tagTreePointerTest03() throws Exception {
     public void tagTreePointerTest04() throws Exception {
         PdfReader reader = new PdfReader(sourceFolder + "taggedDocument.pdf");
         PdfWriter writer = new PdfWriter(destinationFolder + "tagTreePointerTest04.pdf").setCompressionLevel(CompressionConstants.NO_COMPRESSION);
-            PdfDocument document = new PdfDocument(reader, writer);
+        PdfDocument document = new PdfDocument(reader, writer);
 
         TagTreePointer tagPointer = new TagTreePointer(document);
         tagPointer.moveToKid(PdfName.Table).moveToKid(2, PdfName.TR);

kernel/src/test/java/com/itextpdf/kernel/pdf/canvas/parser/PdfCanvasProcessorTest.java

@@ -1,5 +1,6 @@
 package com.itextpdf.kernel.pdf.canvas.parser;
 
+import com.itextpdf.io.LogMessageConstant;
 import com.itextpdf.io.source.ByteArrayOutputStream;
 import com.itextpdf.kernel.pdf.canvas.parser.data.ClippingPathInfo;
 import com.itextpdf.kernel.pdf.canvas.parser.data.IEventData;
@@ -11,6 +12,8 @@
 import com.itextpdf.kernel.pdf.PdfPage;
 import com.itextpdf.kernel.pdf.PdfReader;
 import com.itextpdf.kernel.pdf.PdfWriter;
+import com.itextpdf.test.annotations.LogMessage;
+import com.itextpdf.test.annotations.LogMessages;
 import com.itextpdf.test.annotations.type.IntegrationTest;
 import com.itextpdf.test.ExtendedITextTest;
 
@@ -26,6 +29,7 @@ public class PdfCanvasProcessorTest extends ExtendedITextTest {
     public static final String sourceFolder = "./src/test/resources/com/itextpdf/kernel/parser/PdfCanvasProcessorTest/";
 
     @Test
+    @LogMessages(messages = @LogMessage(messageTemplate = LogMessageConstant.XREF_ERROR, count = 1))
     public void contentStreamProcessorTest() throws IOException {
 
         PdfDocument document = new PdfDocument(new PdfReader(sourceFolder + "yaxiststar.pdf"), new PdfWriter(new ByteArrayOutputStream()));