From 2bb52fcf7dfd63b80f2498e231c4e4d994d038b2 Mon Sep 17 00:00:00 2001
From: Jeroen van Erp <jeroen@hierynomus.com>
Date: Tue, 14 Apr 2020 22:23:35 +0200
Subject: [PATCH] Add checks for Channel.isOpen to ChannelOutputStream (Fixes
 #440)

---
 .../sshj/connection/channel/ChannelOutputStream.java        | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/main/java/net/schmizz/sshj/connection/channel/ChannelOutputStream.java b/src/main/java/net/schmizz/sshj/connection/channel/ChannelOutputStream.java
index 0695d0b8..ad30493f 100644
--- a/src/main/java/net/schmizz/sshj/connection/channel/ChannelOutputStream.java
+++ b/src/main/java/net/schmizz/sshj/connection/channel/ChannelOutputStream.java
@@ -150,7 +150,8 @@ public final class ChannelOutputStream extends OutputStream implements ErrorNoti
     }
 
     private void checkClose() throws SSHException {
-        if (closed) {
+        // Check whether either the Stream is closed, or the underlying channel is closed
+        if (closed || !chan.isOpen()) {
             if (error != null)
                 throw error;
             else
@@ -160,7 +161,8 @@ public final class ChannelOutputStream extends OutputStream implements ErrorNoti
 
     @Override
     public synchronized void close() throws IOException {
-        if (!closed) {
+        // Not closed yet, and underlying channel is open to flush the data to.
+        if (!closed && chan.isOpen()) {
             try {
                 buffer.flush(false);
 //                trans.write(new SSHPacket(Message.CHANNEL_EOF).putUInt32(chan.getRecipient()));