Incorrect &str => f64 results

[alexcrichton]

Perhaps an off-by-one-somewhere?

fn main() {                                 
    let f: f64 = from_str("-3.14").unwrap();
    println!("{}", f);                      
}                                           

$ rustc foo.rs && ./foo
-13.14

cc @bjz, probably related to #18536

[brendanzab]

Ack, sorry! Can't address this just yet - studying for an exam.

[brendanzab]

@SimonSapin also reports:

from_str::<f64>("-2") returns -12.0

[brendanzab]

This commit seems to fix it: juxiliary/rust@f1b51c70f4fe193f98359dfa14a8d16e9f64978d

Could someone make a PR? I am tight for time.

[nixpulvis]

Seems to be fixed by #18713.

[SimonSapin]

Confirmed fixed in #18713, should be closed.

[alexcrichton]

Thanks everyone!