fix: infinite loop while decoding a list of transactions

[Brechtpd]

In network_decode the decoded bytes are not correctly consumed in the buffer which makes decoding break for anything that requires more decoding afterwards, and also makes it possible for the decoding to hang.

[mattsse]

right, we never advanced the input buffer.

this now ensures that the input buffer is consumed

[prestwich]

    #[inline]
    fn advance(&mut self, cnt: usize) {
        if self.len() < cnt {
            panic_advance(cnt, self.len());
        }

        *self = &self[cnt..];
    }

https://docs.rs/bytes/latest/src/bytes/buf/buf_impl.rs.html#1412-1418

Above is the advance code from impl Buf for &[u8]. Can you explain how calling buf.advance(1) differs in behavior from let buf = &mut &buf[1..];

[prestwich]

oohhhh I think i see. It's a "list of transactions" i.e. the inner decoding doesn't consume from the buffer passed to it by the outer list decoder 👍