Failure: Keeping buffer read/size state between pendings STILL doesn"t work...

Fortune for rsh's current commit: Small blessing − 小吉

src/sock/buffered.rs

@@ -232,22 +232,43 @@ impl<T: ?Sized + Unpin, const SIZE: usize> AsyncRead for Buffered<T, SIZE>
 where T: AsyncRead
 {
     fn poll_read(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut [u8]) -> Poll<io::Result<usize>> {
-	use futures::ready;
 
+	
 	let this = self.get_mut();
 	let mut w =0;
 	Poll::Ready(loop {
+
 	    let read = if this.buffer.len() < SIZE
 	    {
+		let st = this.buffer.len();
 		this.buffer.resize(SIZE, 0);
 
-		let mut done=0;
+		let mut done=st;
 		let mut r=0;
+		//XXX: Same issue even trying to save buffer length state over Pendings... Wtf is going on here?
+		macro_rules! ready {
+		    (try $poll:expr) => {
+			match $poll {
+			    Poll::Pending => {
+				this.buffer.resize(done, 0);
+				return Poll::Pending;
+			    },
+			    Poll::Ready(Ok(x)) => x,
+			    err => {
+				this.buffer.resize(done, 0);
+				return err;
+			    }
+			}
+		    }
+		}
 		//                       XXX: V   Same issue, runs the above code twice when re-polling after Pending. We need to make sure we jump back to this point in the code following a Pending poll to `stream.poll_read`, but I have no fucking clue how to do this? Eh...... We'll probably need to design the code differently. There is a lot of state that gets lost here and idk how to preserve it.... I hate this.
-		while done < SIZE && {r = ready!(Pin::new(&mut this.stream).poll_read(cx, &mut this.buffer[done..]))?; r > 0}
+		while done < SIZE && {r = ready!(try Pin::new(&mut this.stream).poll_read(cx, &mut this.buffer[done..])); r > 0}
 		{
 		    done +=r;
 		}
+		// This causes early eof (0)
+		//println!("Done: {}", done);
+		//this.buffer.resize(done, 0);
 		done
 	    } else {
 		SIZE
@@ -318,7 +339,13 @@ mod tests
 
 	let mut output = vec![0u8; DATA.len()*2];
 	// Bug found! Pinning and polling that stack future in `poll_read` does NOT work!
+	// (we unrolled the async function to a poll based one and we're STILL losing state.... FFS!)
 	// The exact same works as a real async function.
+
+/*
+	rx.read(&mut output[..DATA.len()]).await?;
+	rx.read(&mut output[DATA.len()..]).await?;
+*/
 	assert_eq!(rx.read(&mut output[..DATA.len()]).await?, DATA.len());
 	assert_eq!(rx.read(&mut output[DATA.len()..]).await?, DATA.len());