Fix: push/restore (q/Q) losts selected font

[mcerveny]

Problem:

• before text is rendered and self.fill_color!=self.text_color whole context is pushed (q)
• when font is changed, font change is generated and remembered (self.font_style)
• after text is rendering whole context (with old font) is restored (Q) but not restored in self.font_style
• next rendering uses different "subset" table for different font

Proposed solution - restore only self.fill_color

Is this sufficient ?
Is the push/restore only for self.fill_color ?

test.pdf
test_bad.pdf

Test code:

import fpdf

pdf = fpdf.FPDF(orientation='portrait', unit='mm', format='A4', font_cache_dir='pdf/fonts/')
pdf.add_font('dejavusans', fname='pdf/fonts/DejaVuSans.ttf', uni=True)
pdf.add_font('dejavusans', style="B", fname='pdf/fonts/DejaVuSans-Bold.ttf', uni=True)
pdf.add_font('dejavusans', style="I",  fname='pdf/fonts/DejaVuSans-Oblique.ttf', uni=True)
pdf.add_font('dejavusans', style="BI", fname='pdf/fonts/DejaVuSans-BoldOblique.ttf', uni=True)
pdf.add_page()
pdf.set_font('dejavusans',size=10)
pdf.set_fill_color(255,0,0)
pdf.multi_cell(50, markdown=True,txt="aa bb cc **dd ee dd ee dd ee dd ee dd ee dd ee**")
pdf.output('test.pdf')

[Lucas-C]

Thanks for reporting this bug @mcerveny!

I'm not sure on what is the proper fix yet, but I'll look at it very soon.

As a starting point, here is a unit test that could be added to test_multi_cell_markdown.py, based on the code you provided:

def test_multi_cell_markdown_with_fill_color(tmp_path):  # issue 348
    pdf = fpdf.FPDF()
    pdf.add_page()
    pdf.set_font("Times", size=10)
    pdf.set_fill_color(255,0,0)
    pdf.multi_cell(50, markdown=True,txt="aa bb cc **dd ee dd ee dd ee dd ee dd ee dd ee**")
    assert_pdf_equal(pdf, HERE / "multi_cell_markdown_with_fill_color.pdf", tmp_path)

[Lucas-C]

I fixed that bug using a different approach in 3549c0f