XPS conversion PDF lost curve filling

[gpjupc888]

Please provide all mandatory information!

Describe the bug (mandatory)

When I converted the XPS file to PDF, the curve fill was lost in the PDF file.

To Reproduce (mandatory)

import fitz
from tkinter import filedialog
path = filedialog.askopenfilename()
xps_doc = fitz.open(path)
pdfBytes = xps_doc.convert_to_pdf()
pdf_doc = fitz.open('pdf', pdfBytes)
save_path = path.split('.')[0] + '.pdf'
pdf_doc.save(save_path)

Expected behavior (optional)

I hope it can be completely converted into A PDF file. Could you please help me find out where the problem is

Screenshots (optional)

In Figure 1, the fourth plot is filled with color.

But in Figure 2, which is my converted PDF file, the color fill of the fourth chart disappears.

Your configuration (mandatory)

PyMuPDF 1.18.15: Python bindings for the MuPDF 1.18.0 library.
Version date: 2021-07-10 00:00:01.
Built for Python 3.8 on win32 (64-bit).

Additional context (optional)

Here are the XPS files and converted PDF files I used for testing.
xpstest.pdf
xpstest.zip

Thank you very much.

[JorjMcKie]

Thank you for the well-prepared issue.
Unfortunately, this is no bug inside PyMuPDF. The PyMuPDF code uses directly MuPDF to do the conversion.
I was able to reproduce the error via CLI command mutool convert -o xpstest.pdf xpstest.xps.

All you can do is submit this bug to https://bugs.ghostscript.com/enter_bug.cgi and attach the XPS file and the above conversion command alongside a short description.

[JorjMcKie]

I am moving this issue to Discussions, alongside other upstream issues.