Review

PdfArray.getPdfObject() is invoked without checking that the array contains sufficiently many objects.

• missing/condition/value_or_state

com/itextpdf/text/pdf/PdfStructureTreeRoot.java

nodeProcess(PdfDictionary, PdfIndirectReference)

class PdfStructureTreeRoot {
    private void nodeProcess(PdfDictionary struc, PdfIndirectReference reference) throws IOException {
        PdfObject obj = struc.get(PdfName.K);
        if (obj != null && obj.isArray() && !(((PdfArray)obj).getPdfObject(0)).isNumber()) {
            PdfArray ar = (PdfArray)obj;
            for (int k = 0; k < ar.size(); ++k) {
                PdfStructureElement e = (PdfStructureElement)ar.getAsDict(k);
                ar.set(k, e.getReference());
                nodeProcess(e, e.getReference());
            }
        }
        if (reference != null)
            writer.addToBody(struc, reference);
    }

}