Out of bounds access when parsing 0 at end of input

[dtolnay]

Adding assert!(self.index < self.length) to Parse::read_byte catches this.

Example inputs that trigger the bug:

• 0
• -0
• [0
• {"":0

[dtolnay]

extern crate json;

use std::str;

fn main() {
    let data = b"0.123456789";
    let s = str::from_utf8(&data[..1]).unwrap();
    println!("{:?}", s);
    println!("{:?}", json::parse(s));
}

"0"
thread 'main' panicked at 'byte index 12 is out of bounds of `0`', /checkout/src/libcore/str/mod.rs:1775

[maciejhirsz]

Thanks!

I've added a debug_assert for the future. I've been plotting a pretty major rewrite based on some experience I got by now when dealing with another project. Not very happy about code quality in the parser here.