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use futures::{
executor::block_on,
io::{self, AsyncRead, AsyncReadExt},
task::{Context, Poll},
};
use std::pin::Pin;
#[test]
#[should_panic(expected = "assertion failed: n <= buf.len()")]
fn issue2310() {
struct MyRead {
first: bool,
}
impl MyRead {
fn new() -> Self {
MyRead { first: false }
}
}
impl AsyncRead for MyRead {
fn poll_read(
mut self: Pin<&mut Self>,
_cx: &mut Context,
_buf: &mut [u8],
) -> Poll<io::Result<usize>> {
Poll::Ready(if !self.first {
self.first = true;
// First iteration: return more than the buffer size
Ok(64)
} else {
// Second iteration: indicate that we are done
Ok(0)
})
}
}
struct VecWrapper {
inner: Vec<u8>,
}
impl VecWrapper {
fn new() -> Self {
VecWrapper { inner: Vec::new() }
}
}
impl Drop for VecWrapper {
fn drop(&mut self) {
// Observe uninitialized bytes
println!("{:?}", &self.inner);
// Overwrite heap contents
for b in &mut self.inner {
*b = 0x90;
}
}
}
block_on(async {
let mut vec = VecWrapper::new();
let mut read = MyRead::new();
read.read_to_end(&mut vec.inner).await.unwrap();
})
}