checked_div can divide by zero

[turion]

It's possible to panic with a zero division by using checked_div.

#![allow(dead_code)]
#![warn(clippy::pedantic)]

use num_rational::Ratio;
use num_traits::ops::checked::CheckedDiv;

fn main() {
    #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
    let x = Ratio::from(0);
    dbg!(x.checked_div(&x));
}

Playground

The reason seems to be that the gcds are divided unsafely:

num-rational/src/lib.rs

Line 779 in 957e232

.checked_mul(&(rhs.numer.clone() / gcd_ac.clone()))?;

Probably, one should use otry!(checked_div(...) or something similar.

[cuviper]

Thanks for the report. AFAICS this only happens when both the dividend and divisor are 0, as that's the only case that lets the gcd be 0 as well. This is also a regression in 0.2.3, as of #42.

[cuviper]

This should be fixed in 0.2.4.

[turion]

Thanks for the quick response, fix and release!