From 56fc6c3955f504a7b51b7d6de31cc8efe930ef72 Mon Sep 17 00:00:00 2001
From: Bob Lantz <rlantz@cs.stanford.edu>
Date: Thu, 12 Jul 2018 01:33:36 +0000
Subject: [PATCH] Close popen stdout and stderr

They should get cleaned up anyway, but Python 3 gives
us an error message. This silences it.
---
 mininet/util.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mininet/util.py b/mininet/util.py
index 3b80f58..1269410 100644
--- a/mininet/util.py
+++ b/mininet/util.py
@@ -130,6 +130,10 @@ def errRun( *cmd, **kwargs ):
                 poller.unregister( fd )
 
     returncode = popen.wait()
+    # Python 3 complains if we don't explicitly close these
+    popen.stdout.close()
+    if stderr == PIPE:
+        popen.stderr.close()
     debug( out, err, returncode )
     return out, err, returncode
 # pylint: enable=too-many-branches