From ca7333cb92fba65a8280d0faba5fea4dbc9b2051 Mon Sep 17 00:00:00 2001
From: Dominik Csapak <d.csapak@proxmox.com>
Date: Tue, 14 Jul 2020 13:09:52 +0200
Subject: [PATCH] proxmox/tools/websocket: correctly return eof

only return Ok(0) when the upstream reader did return that, not when
we have no data in the buffer, else the downstream reader believes
we are EOF (even if we are not)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
---
 proxmox/src/tools/websocket.rs | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/proxmox/src/tools/websocket.rs b/proxmox/src/tools/websocket.rs
index c30293f5..d59b7ad6 100644
--- a/proxmox/src/tools/websocket.rs
+++ b/proxmox/src/tools/websocket.rs
@@ -432,7 +432,7 @@ impl<R: AsyncReadExt> WebSocketReader<R> {
 
 enum ReaderState<R> {
     NoData,
-    WaitingForData(Pin<Box<dyn Future<Output = Result<(R, ByteBuffer), Error>> + Send + 'static>>),
+    WaitingForData(Pin<Box<dyn Future<Output = Result<(usize, R, ByteBuffer), Error>> + Send + 'static>>),
     HaveData,
 }
 
@@ -463,18 +463,20 @@ impl<R: AsyncReadExt + Unpin + Send + 'static> AsyncRead for WebSocketReader<R>
                     let future = async move {
                         buffer.read_from_async(&mut reader)
                             .await
-                            .map(move |_| (reader, buffer))
+                            .map(move |len| (len, reader, buffer))
                     };
 
                     this.state = ReaderState::WaitingForData(future.boxed());
                 },
                 ReaderState::WaitingForData(ref mut future) => {
                     match ready!(future.as_mut().poll(cx)) {
-                        Ok((reader, buffer)) => {
+                        Ok((len, reader, buffer)) => {
                             this.reader = Some(reader);
                             this.read_buffer = Some(buffer);
                             this.state = ReaderState::HaveData;
-
+                            if len == 0 {
+                                return Poll::Ready(Ok(0));
+                            }
                         },
                         Err(err) => return Poll::Ready(Err(Error::new(ErrorKind::Other, err))),
                     }
@@ -545,7 +547,9 @@ impl<R: AsyncReadExt + Unpin + Send + 'static> AsyncRead for WebSocketReader<R>
                     };
                     this.read_buffer = Some(read_buffer);
 
-                    return Poll::Ready(Ok(offset));
+                    if offset > 0 {
+                        return Poll::Ready(Ok(offset));
+                    }
                 },
             }
         }