Issue #10883: Fix socket leaks in urllib.request.

* ftpwrapper now uses reference counting to ensure that the underlying socket
  is closed when the ftpwrapper object is no longer in use
* ftplib.FTP.ntransfercmd() now closes the socket if an error occurs

Initial patch by Victor Stinner.

2 files changed, 2 insertions, 0 deletions

diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py
index e889bc3d10..e2473159dd 100644
--- a/Lib/test/test_urllib2.py
+++ b/Lib/test/test_urllib2.py
@@ -611,6 +611,7 @@ class HandlerTests(unittest.TestCase):
             def retrfile(self, filename, filetype):
                 self.filename, self.filetype = filename, filetype
                 return StringIO.StringIO(self.data), len(self.data)
+            def close(self): pass
 
         class NullFTPHandler(urllib2.FTPHandler):
             def __init__(self, data): self.data = data
diff --git a/Lib/test/test_urllib2net.py b/Lib/test/test_urllib2net.py
index 867fcfa41e..5ffba87fdf 100644
--- a/Lib/test/test_urllib2net.py
+++ b/Lib/test/test_urllib2net.py
@@ -231,6 +231,7 @@ class OtherNetworkTests(unittest.TestCase):
         handlers = []
 
         cfh = urllib2.CacheFTPHandler()
+        self.addCleanup(cfh.clear_cache)
         cfh.setTimeout(1)
         handlers.append(cfh)