call .write_html in footer cause RecursionError

[socrateslee]

Describe the bug

Error details Call .write_html in footer will result in a recursive call _perform_page_break -> add_page -> footer loop, therefore result in a RecursionError: maximum recursion depth exceeded error.

Minimal code

import fpdf

def render():
    class MyPDF(fpdf.FPDF):
            def footer(sub):
                sub.set_y(-15)
                sub.write_html("<p>this is a footer</p>")
    pdf = MyPDF(format='A4')
    pdf.add_page()
    pdf.write_html("<p>this is main content</p>")
    pdf.output('test.pdf')

render()

Environment Please provide the following information:

• Operating System: Windows with WSL2...
• Python version: python 3.12
• fpdf2 version used: fpdf2 @ git+https://github.com/py-pdf/fpdf2@6f7a207d9c0b7e3f537b6a5f9f25e6ab0b693f8e

[gmischler]

Thanks for reporting this, and welcome to fpdf2, @socrateslee !

That's quite an interesting bug you found there. We should probably disable automatic page breaks while actually processing a page break (and when writing the last footer at the end of the document).

[Lucas-C]

@allcontributors please add @socrateslee for bug

@socrateslee: would you like to submit a PR to fix this? A good starting point would be to add unit test for this cas in test/html/test_html.py

[allcontributors[bot]]

@Lucas-C

I've put up a pull request to add @socrateslee! :tada:

[Lucas-C]

I opened #1247 to fix this.