Adding a header with only a space causes a segmentation fault

[dldx]

Thanks for this very helpful package!

I just noticed a very strange bug occuring due to pymupdf.

The following sample code causes a segmentation fault:

from markdown_pdf import MarkdownPdf, Section
pdf = MarkdownPdf(toc_level=2)
pdf.add_section(Section("# "))

Result with gdb:

Starting program: ./venv/bin/python test.py

This GDB supports auto-downloading debuginfo from the following URLs:
  <https://debuginfod.ubuntu.com>
Enable debuginfod for this session? (y or [n]) y
Debuginfod has been enabled.
To make this setting permanent, add 'set debuginfod enabled on' to .gdbinit.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Downloading separate debug info for ./venv/lib/python3.11/site-packages/fitz/_extra.cpython-311-x86_64-linux-gnu.so
Downloading separate debug info for ./venv/lib/python3.11/site-packages/fitz/libmupdf.so.24.1                                                                                 
Downloading separate debug info for ./venv/lib/python3.11/site-packages/fitz/libmupdfcpp.so.24.1                                                                              
Downloading separate debug info for ./venv/lib/python3.11/site-packages/fitz/_mupdf.so                                                                                        
                                                                                                                                                                                                                        
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56e5ad2 in ?? () from ./venv/lib/python3.11/site-packages/fitz/libmupdf.so.24.1

The bug appears to be in the fitz package but I'm unsure where to file it.

Cheers

[vb64]

Thanks for bug report.

More detailed description for this bug is here:

#38

[vb64]

Fixed in version 1.3.3. Please, update your installation.