turtle.setworldscoordinates() and floating point precision

Empieza ejecutando el reproductor de espiral de turtle proporcionado e inspecciona Lib/turtle.py alrededor de la línea 1105. Sigue cómo setworldcoordinates actualiza xscale y yscale, y compara el error de coma flotante de Tk con el ZeroDivisionError de RawTurtle. Se considera terminado cuando el comportamiento en el límite de precisión se gestiona sin una pantalla en blanco ni un bloqueo, con cobertura para las condiciones límite indicadas.

I made a turtle draw a spiral while rescaling the screen according to the last position of the turtle.

Simple code to reproduce (increasing the speed variable will make it crash sooner):

"""Crash a Turtle with negative infinity canvas scale"""
import turtle

speed = 3

angle = 0
radius = 1
boundaries = {'llx': -1.0, 'lly': -1.0, 'urx': 1.0, 'ury': 1.0}
pen = turtle.Turtle()
pen.speed(10)
pen.getscreen().tracer(1e3)
while True:
    print(f"radius {radius}, angle {angle}")
    print(f"screen xscale {pen.getscreen().xscale}")
    print(f"screen yscale {pen.getscreen().yscale}")
    pen.circle(radius, angle)
    radius *= speed
    angle += 1
    pos = pen.pos()
    boundaries['llx'] = min(boundaries['llx'], pos[0])
    boundaries['lly'] = min(boundaries['lly'], pos[1])
    boundaries['urx'] = max(boundaries['urx'], pos[0])
    boundaries['ury'] = max(boundaries['ury'], pos[1])
    pen.getscreen().setworldcoordinates(**boundaries)

This will raise _tkinter.TclError: expected floating-point number but got "floating" when x or y scale gets near 1e-306.

But in the code I'm using with a RawTurtle and a TurtleScreen I get ZeroDivisionError because somewhere after 6.7e-307 (in my machine) both TurtleScreen's x and y scales becomes 0.0, RawTurtle's position becomes (-inf, -inf) and then this line of code is reached: https://github.com/python/cpython/blob/3ef9f6b508a8524f385cdc9fdd4b4afca0eac59b/Lib/turtle.py#L1105

I had to set this in my code to prevent screen becoming blank (because of scale becoming 0.0), so I could stop drawing before it crashes:

precision: int = 1e-306
while True:
    logger.debug(f"""
boundaries = {boundaries}
screen.xscale = {screen.xscale}
screen.yscale = {screen.yscale}
""")
    try:
        1 / screen.xscale
        1 / screen.yscale
    except ZeroDivisionError:
        logger.warning(f"reached infinity")
        break
    if precision != min(precision, screen.xscale, screen.yscale):
        logger.warning(f"reached floating point precision limit")
        break
    screen.setworldcoordinates(**boundaries)
## Make screen still without going blank
root.mainloop()