Comment 12 for bug 774052

This 'lowagie' bug seems to still be active. On my Ubuntu system, the 1971 Simon PDF "Designing Organizations for an Information-Rich World" https://veryinteractive.net/pdfs/simon_designing-organizations-for-an-information-rich-world.pdf (MD5: `1c7cceee6de48ba3ab80db269295e136`) crashes any pdftk invocation as follows:

$ pdftk 1971-simon.pdf cat output foo.pdf
Error: Unexpected Exception in open_reader()
java.lang.ClassCastException: class pdftk.com.lowagie.text.pdf.PdfNull cannot be cast to class pdftk.com.lowagie.text.pdf.PdfDictionary (pdftk.com.lowagie.text.pdf.PdfNull and pdftk.com.lowagie.text.pdf.PdfDictionary are in unnamed module of loader 'app')
 at pdftk.com.lowagie.text.pdf.PdfReader$PageRefs.iteratePages(PdfReader.java:3420)
 at pdftk.com.lowagie.text.pdf.PdfReader$PageRefs.iteratePages(PdfReader.java:3449)
 at pdftk.com.lowagie.text.pdf.PdfReader$PageRefs.iteratePages(PdfReader.java:3449)
 at pdftk.com.lowagie.text.pdf.PdfReader$PageRefs.readPages(PdfReader.java:3256)
 at pdftk.com.lowagie.text.pdf.PdfReader$PageRefs.<init>(PdfReader.java:3226)
 at pdftk.com.lowagie.text.pdf.PdfReader$PageRefs.<init>(PdfReader.java:3204)
 at pdftk.com.lowagie.text.pdf.PdfReader.readPages(PdfReader.java:925)
 at pdftk.com.lowagie.text.pdf.PdfReader.readPdf(PdfReader.java:523)
 at pdftk.com.lowagie.text.pdf.PdfReader.<init>(PdfReader.java:172)
 at pdftk.com.lowagie.text.pdf.PdfReader.<init>(PdfReader.java:161)
 at com.gitlab.pdftk_java.TK_Session.add_reader(TK_Session.java:126)
 at com.gitlab.pdftk_java.TK_Session.add_reader(TK_Session.java:229)
 at com.gitlab.pdftk_java.TK_Session.open_input_pdf_readers(TK_Session.java:242)
 at com.gitlab.pdftk_java.TK_Session.<init>(TK_Session.java:869)
 at com.gitlab.pdftk_java.pdftk.main_noexit(pdftk.java:150)
 at com.gitlab.pdftk_java.pdftk.main(pdftk.java:128)
Error: Failed to open PDF file:
   1971-simon.pdf
Errors encountered. No output created.
Done. Input errors, so no output created.
$ pdftk --version
pdftk port to java 3.0.9 a Handy Tool for Manipulating PDF Documents
Copyright (c) 2017-2018 Marc Vinyals - https://gitlab.com/pdftk-java/pdftk
Copyright (c) 2003-2013 Steward and Lee, LLC.
pdftk includes a modified version of the iText library.
Copyright (c) 1999-2009 Bruno Lowagie, Paulo Soares, et al.