urllib: socket is not closed explicitly

Lib/ftplib.py

 """An FTP client class and some helper functions.
 
 Based on RFC 959: File Transfer Protocol (FTP), by J. Postel and J. Reynolds
 
 Example:
 
 >>> from ftplib import FTP
 >>> ftp = FTP('ftp.python.org') # connect to host, default port
 >>> ftp.login() # default, i.e.: user anonymous, passwd anonymous@
 '230 Guest login ok, access restrictions apply.'
@@ skipping 325 matching lines @@
         Optional `rest' argument can be a string that is sent as the
         argument to a REST command.  This is essentially a server
         marker used to tell the server to skip over any data up to the
         given marker.
         """
         size = None
         if self.passiveserver:
             host, port = self.makepasv()
             conn = socket.create_connection((host, port), self.timeout,
                                             source_address=self.source_address)
-            if rest is not None:
-                self.sendcmd("REST %s" % rest)
-            resp = self.sendcmd(cmd)
-            # Some servers apparently send a 200 reply to
-            # a LIST or STOR command, before the 150 reply
-            # (and way before the 226 reply). This seems to
-            # be in violation of the protocol (which only allows
-            # 1xx or error messages for LIST), so we just discard
-            # this response.
-            if resp[0] == '2':
-                resp = self.getresp()
-            if resp[0] != '1':
-                raise error_reply(resp)
+            try:
+                if rest is not None:
+                    self.sendcmd("REST %s" % rest)
+                resp = self.sendcmd(cmd)
+                # Some servers apparently send a 200 reply to
+                # a LIST or STOR command, before the 150 reply
+                # (and way before the 226 reply). This seems to
+                # be in violation of the protocol (which only allows
+                # 1xx or error messages for LIST), so we just discard
+                # this response.
+                if resp[0] == '2':
+                    resp = self.getresp()
+                if resp[0] != '1':
+                    raise error_reply(resp)
+            except:
+                conn.close()
+                raise
         else:
             sock = self.makeport()
             if rest is not None:
                 self.sendcmd("REST %s" % rest)
             resp = self.sendcmd(cmd)
             # See above.
             if resp[0] == '2':
                 resp = self.getresp()
             if resp[0] != '1':
                 raise error_reply(resp)
@@ skipping 740 matching lines @@
         elif file == '-p':
             ftp.set_pasv(not ftp.passiveserver)
         else:
             ftp.retrbinary('RETR ' + file, \
                            sys.stdout.write, 1024)
     ftp.quit()
 
 
 if __name__ == '__main__':
     test()