From a877ec1448174a512c001556ad59709002060e3a Mon Sep 17 00:00:00 2001
From: Shikhar Bhushan <shikhar@schmizz.net>
Date: Wed, 6 Jun 2012 22:55:35 +0100
Subject: [PATCH] AbstractChannel#close() should be no-op if already closed.
 Fixes #53.

---
 .../sshj/connection/channel/AbstractChannel.java   | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/main/java/net/schmizz/sshj/connection/channel/AbstractChannel.java b/src/main/java/net/schmizz/sshj/connection/channel/AbstractChannel.java
index 09209950..92a43332 100644
--- a/src/main/java/net/schmizz/sshj/connection/channel/AbstractChannel.java
+++ b/src/main/java/net/schmizz/sshj/connection/channel/AbstractChannel.java
@@ -258,13 +258,15 @@ public abstract class AbstractChannel
             throws ConnectionException, TransportException {
         openCloseLock.lock();
         try {
-            try {
-                sendClose();
-            } catch (TransportException e) {
-                if (!closeEvent.inError())
-                    throw e;
+            if (isOpen()) {
+                try {
+                    sendClose();
+                } catch (TransportException e) {
+                    if (!closeEvent.inError())
+                        throw e;
+                }
+                closeEvent.await(conn.getTimeout(), TimeUnit.SECONDS);
             }
-            closeEvent.await(conn.getTimeout(), TimeUnit.SECONDS);
         } finally {
             openCloseLock.unlock();
         }