Integer overflow when decoding a `}`

[finnbear]

I noticed the library panics on certain inputs containing }:

[dependencies]
base85 = "2.0.0"

fn main() {
    println!("{:?}", base85::decode("}"));
}

$ cargo run
thread 'main' panicked at 'attempt to multiply with overflow', /home/finnb/.cargo/registry/src/index.crates.io-6f17d22bba15001f/base85-2.0.0/src/lib.rs:158:27

$ cargo run --release
Err(UnexpectedEof)

As far as I can tell, it is trying to compute 83*85^4=4332651875 which overflows u32.

[darkwyrm]

Although you can encode anything, not everything is valid Base85. A single '}' character is invalid and should result in an error. The fact that it panics is a bug that I'll look into in the very near future.