Review

Iterator.next() is invoked without prior check of hasNext().

• missing/condition/value_or_state

com/itextpdf/text/pdf/PdfWriter.java

writeCrossReferenceTable(OutputStream, PdfIndirectReference, PdfIndirectReference, PdfIndirectReference, PdfObject, long)

class PdfWriter.PdfBody {
        void writeCrossReferenceTable(final OutputStream os, final PdfIndirectReference root, final PdfIndirectReference info, final PdfIndirectReference encryption, final PdfObject fileID, final long prevxref) throws IOException {
            int refNumber = 0;
            if (writer.isFullCompression()) {
                flushObjStm();
                refNumber = getIndirectReferenceNumber();
                xrefs.add(new PdfCrossReference(refNumber, position));
            }
            PdfCrossReference entry = xrefs.first();
            int first = entry.getRefnum();
            int len = 0;
            ArrayList<Integer> sections = new ArrayList<Integer>();
            for (PdfCrossReference pdfCrossReference : xrefs) {
                entry = pdfCrossReference;
                if (first + len == entry.getRefnum())
                    ++len;
                else {
                    sections.add(Integer.valueOf(first));
                    sections.add(Integer.valueOf(len));
                    first = entry.getRefnum();
                    len = 1;
                }
            }
            sections.add(Integer.valueOf(first));
            sections.add(Integer.valueOf(len));
            if (writer.isFullCompression()) {
                int mid = 5;
                long mask = 0xff00000000L;
                for (; mid > 1; --mid) {
                    if ((mask & position) != 0)
                        break;
                    mask >>>= 8;
                }
                ByteBuffer buf = new ByteBuffer();

                for (Object element : xrefs) {
                    entry = (PdfCrossReference) element;
                    entry.toPdf(mid, buf);
                }
                PdfStream xr = new PdfStream(buf.toByteArray());
                buf = null;
                xr.flateCompress(writer.getCompressionLevel());
                xr.put(PdfName.SIZE, new PdfNumber(size()));
                xr.put(PdfName.ROOT, root);
                if (info != null) {
                    xr.put(PdfName.INFO, info);
                }
                if (encryption != null)
                    xr.put(PdfName.ENCRYPT, encryption);
                if (fileID != null)
                    xr.put(PdfName.ID, fileID);
                xr.put(PdfName.W, new PdfArray(new int[]{1, mid, 2}));
                xr.put(PdfName.TYPE, PdfName.XREF);
                PdfArray idx = new PdfArray();
                for (int k = 0; k < sections.size(); ++k)
                    idx.add(new PdfNumber(sections.get(k).intValue()));
                xr.put(PdfName.INDEX, idx);
                if (prevxref > 0)
                    xr.put(PdfName.PREV, new PdfNumber(prevxref));
                PdfEncryption enc = writer.crypto;
                writer.crypto = null;
                PdfIndirectObject indirect = new PdfIndirectObject(refNumber, xr, writer);
                indirect.writeTo(writer.getOs());
                writer.crypto = enc;
            }
            else {
                os.write(getISOBytes("xref\n"));
                Iterator<PdfCrossReference> i = xrefs.iterator();
                for (int k = 0; k < sections.size(); k += 2) {
                    first = sections.get(k).intValue();
                    len = sections.get(k + 1).intValue();
                    os.write(getISOBytes(String.valueOf(first)));
                    os.write(getISOBytes(" "));
                    os.write(getISOBytes(String.valueOf(len)));
                    os.write('\n');
                    while (len-- > 0) {
                        entry = i.next();
                        entry.toPdf(os);
                    }
                }
            }
        }

}