Shared via Rust Playground

playground.rs

...


macro_rules! nada {
    () => { unsafe { std::mem::uninitialized() } }
}

#[derive(Debug)]
struct Konnection {
    hp : String,
    cred : String,
    sock : TcpStream,
}


fn konnect( hostport : &str, name : &str, passwd : &str ) -> Konnection {

    let mut k : Konnection = nada!();
    
    let mut cred = name.to_string();
    cred.push( ':' );
    cred.push_str( passwd );
    
    // here k.cred contains some garbage (including a pointer containg random bits)
    k.cred = cred;
    // reassignment destroys old value, and tries calls free() on that random pointer!

    ...
}