Bug summary

removed_chars = r'<>:"/|?\0 ' in get_default_filename has r before string so escape char '' is ignored in the string, so it just replace regular zero character '0' with '_'
just replace removed_chars = r'<>:"/|?\0 ' with removed_chars = '<>:"/\|?*\0 '

Code for reproduction

# create a plot and set title to sth with 0 in it
fig.canvas.set_window_title('120')
# then click on save button

Actual outcome

It shows save dialog with 12_.png file name

Expected outcome

It should show save dialog with 120.png file name

Additional information

No response

Operating system

No response

Matplotlib Version

All

Matplotlib Backend

All

Python version

All

Jupyter version

All

Installation

None