From efc991547ee0a283425373aa4dcf6c68ba3d5717 Mon Sep 17 00:00:00 2001
From: Bob Lantz <rlantz@cs.stanford.edu>
Date: Tue, 20 Mar 2012 15:46:54 -0700
Subject: [PATCH] Add warning in defaultIntf() if host has no interfaces.

Possibly this should be in intf() instead, as intf() is assumed
to always succeed.
---
 mininet/node.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/mininet/node.py b/mininet/node.py
index ad73ef5..9c9dbef 100644
--- a/mininet/node.py
+++ b/mininet/node.py
@@ -310,16 +310,19 @@ class Node( object ):
         ports = self.intfs.keys()
         if ports:
             return self.intfs[ min( ports ) ]
+        else:
+            warn( '*** defaultIntf: warning:', self.name,
+                 'has no interfaces\n' )
 
     def intf( self, intf='' ):
-        """Return our interface object with given name,x
+        """Return our interface object with given name,
            or default intf if name is empty"""
         if not intf:
             return self.defaultIntf()
         elif type( intf) is str:
             return self.nameToIntf[ intf ]
         else:
-            return intf
+            return None
 
     def connectionsTo( self, node):
         "Return [ intf1, intf2... ] for all intfs that connect self to node."