From 6417f5a3cac8537ac6f6ff7fc1642dfaa0917fb4 Mon Sep 17 00:00:00 2001
From: Jakub Jelen <jjelen@redhat.com>
Date: Thu, 16 Apr 2020 11:13:34 +0200
Subject: [PATCH] channels: Avoid returning SSH_AGAIN from
 ssh_channel_poll_timeout()

This addresses a regression introduced in 3bad0607, partially fixed in 022409e9,
but the function was still able to return SSH_AGAIN, which was not expected by
callers.

Based on discussion in [1] and [2]

[1] https://gitlab.com/libssh/libssh-mirror/-/merge_requests/101
[2] https://www.libssh.org/archive/libssh/2020-03/0000029.html

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Anderson Toshiyuki Sasaki <ansasaki@redhat.com>

[Backport from upstream commit:
6417f5a3cac8537ac6f6ff7fc1642dfaa0917fb4]
Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
---
 src/channels.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/channels.c b/src/channels.c
index bcc1c207..9fe309d0 100644
--- a/src/channels.c
+++ b/src/channels.c
@@ -3116,6 +3116,12 @@ int ssh_channel_poll_timeout(ssh_channel channel, int timeout, int is_stderr)
         session->session_state == SSH_SESSION_STATE_ERROR) {
         rc = SSH_ERROR;
         goto out;
+    } else if (rc == SSH_AGAIN) {
+        /* If the above timeout expired, it is ok and we do not need to
+         * attempt to check the read buffer. The calling functions do not
+         * expect us to return SSH_AGAIN either here. */
+        rc = SSH_OK;
+        goto out;
     }
     len = ssh_buffer_get_len(stdbuf);
     if (len > 0) {
-- 
2.20.1