From 81c7edc1a4561cabc396a4a2ad528e8c78570b71 Mon Sep 17 00:00:00 2001
From: Robey Pointer <robey@twitter.com>
Date: Sun, 25 Apr 2010 16:42:45 -0700
Subject: [PATCH] patch from Shad Sharma to raise an exception if the transport
 isn't active when you try to open a new channel.

---
 paramiko/transport.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/paramiko/transport.py b/paramiko/transport.py
index 50e78e7..758ba37 100644
--- a/paramiko/transport.py
+++ b/paramiko/transport.py
@@ -706,10 +706,8 @@ class Transport (threading.Thread):
         @raise SSHException: if the request is rejected or the session ends
             prematurely
         """
-        chan = None
         if not self.active:
-            # don't bother trying to allocate a channel
-            return None
+            raise SSHException('SSH session not active')
         self.lock.acquire()
         try:
             chanid = self._next_channel()