bigint add function cause Segmentation fault

[ksh8281]

i worked with rust(bf98981)

i try to use bigint module. but bigint.add function cause segfault in some cases.
the cases is below

extern mod extra;

use extra::bigint;
use extra::bigint::BigInt;
use extra::bigint::FromStr;
fn main() {
    let a:bigint::BigInt = FromStr::from_str("31").unwrap();
    let b:bigint::BigInt = FromStr::from_str("999999999999999999999999999999999999").unwrap();
    let c = (a+b).to_str();
    println(format!("{:?}",c));
}

[huonw]

@cmr has run this testcase on some months-old compilers, and it still crashes with them; so it looks like this has existed forever and isn't a (recent) regression. (Just as a general data point.)

[thestinger]

This causes a failure for me:

task '<main>' failed at 'vector size is too large: 18446744073709551615', /build/rust-git/src/rust/src/libstd/vec.rs:191

[emberian]

Aha, I must have fixed this with the check-for-overflow. I'll add tests for this.

[huonw]

I don't think this is fixed, the fundamental problem of the bigint implementation of to_str being wrong is still there.

[emberian]

@huonw I opened #10522 about fixing the overflow issues.