Potencial division by zero in turtle.py

[evdakim1234]

Bug report

Bug description:

A static analysis tool reported several potential division by zero vulnerabilities in
Lib/turtle.py
value xspan can be 0

xspan = float(urx - llx)
self.xscale = self.canvwidth / xspan

Lib/turtle.py
value yspan can be 0

yspan = float(ury - lly)
self.yscale = self.canvheight / yspan

Lib/turtle.py
value steps can be 0

    steps = 1+int(min(11+abs(radius)/6.0, 59.0)*frac)
w = 1.0 * extent / steps

CPython versions tested on:

3.13

Operating systems tested on:

Linux

Linked PRs

• gh-157244: Fix potential division by zero in turtle.py #157245

[encukou]

If you provide wrong input, you get an exception. This is not a bug.