Replace this: What happened? What were you trying to achieve?

Environment

Which environment were you using when you encountered the problem?

$ python -m platform

macOS-10.16-x86_64-i386-64bit

$ python -c "import PyPDF2;print(PyPDF2.__version__)"

2.11.2

Code + PDF

This is a minimal, complete example that shows the issue:

def write_public(pdf_name, output_folders):
    split_names = gen_split_names(pdf_name)
    input_pdf = PdfFileReader(open(pdf_name, "rb"))
    num_partitions = len(output_folders)
    for num_person in range(len(split_names)):
        if num_person == len(split_names) - 1:
            end = input_pdf.numPages
        else:
            end = split_names[num_person+1][0]
        output = PdfFileWriter()
        for page_num in range(split_names[num_person][0], end):
            output.addPage(input_pdf.getPage(page_num))
        with open(output_folders[num_person % num_partitions] + "/" + split_names[num_person][1][0]+split_names[num_person][1][
            1]+".pdf",
                  "wb") as outstream:
            output.write(outstream)

Share here the PDF file(s) that cause the issue. The smaller they are, the
better. Let us know if we may add them to our tests!

I (legally) can't share the PDF, but I can say that I ran this code on some 240 pdfs, and it broke on only this one pdf. The only thing I find different about this pdf is a bunch of math equations in LaTeX. Please feel free to close this issue, I understand non reproducible bug reports aren't exactly useful, but figured I'd give it a shot.

Traceback

This is the complete Traceback I see:
File "/Users/tynanseltzer/test2/splitter.py", line 135, in
write_public(PUBLIC_PDF, fls)
File "/Users/tynanseltzer/test2/splitter.py", line 64, in write_public
output.write(outstream)
File "/Users/tynanseltzer/anaconda3/lib/python3.9/site-packages/PyPDF2/_writer.py", line 832, in write
self.write_stream(stream)
File "/Users/tynanseltzer/anaconda3/lib/python3.9/site-packages/PyPDF2/_writer.py", line 805, in write_stream
self._sweep_indirect_references(self._root)
File "/Users/tynanseltzer/anaconda3/lib/python3.9/site-packages/PyPDF2/_writer.py", line 954, in _sweep_indirect_references
data = self._resolve_indirect_object(data)
File "/Users/tynanseltzer/anaconda3/lib/python3.9/site-packages/PyPDF2/_writer.py", line 999, in _resolve_indirect_object
real_obj = data.pdf.get_object(data)
File "/Users/tynanseltzer/anaconda3/lib/python3.9/site-packages/PyPDF2/_reader.py", line 1222, in get_object
retval = read_object(self.stream, self) # type: ignore
File "/Users/tynanseltzer/anaconda3/lib/python3.9/site-packages/PyPDF2/generic/_data_structures.py", line 872, in read_object
stream.read(-20)
ValueError: read length must be non-negative or -1