Using Python 3.6.3.

The below issue only happens with FTP_TLS. It works fine via a plain FTP connection.

I am connecting to an FTP to using `ftplib` via FTP_TLS.

	ftps = ftplib.FTP_TLS('example.com', timeout=5)

	# TLS is more secure than SSL
	ftps.ssl_version = ssl.PROTOCOL_TLS

	# login before securing control channel
	ftps.login('username@example.com', 'password')

	# switch to secure data connection
	ftps.prot_p()

	# Explicitly set Passive mode
	ftps.set_pasv(True)

This all works. I can send `ftps.mkd('mydir')` (make directory) and `ftps.cwd('mydir')` (change working dir), and both work fine.

But if I send **any** of these (they're all basically synonyms as far as I can tell):

			ftps.dir()
			ftps.nlst()
			ftps.retrlines('LIST')
			ftps.retrlines('MLSD')

Then I get back an exception (below also includes all ftplib debug info as well; generally matches up with what FileZilla shows too):

	*cmd* 'AUTH TLS'
	*put* 'AUTH TLS\r\n'
	*get* '234 AUTH TLS OK.\n'
	*resp* '234 AUTH TLS OK.'
	*cmd* 'USER username@example.com'
	*put* 'USER username@example.com\r\n'
	*get* '331 User username@example.com OK. Password required\n'
	*resp* '331 User username@example.com OK. Password required'
	*cmd* 'PASS ******************************'
	*put* 'PASS ******************************\r\n'
	*get* '230 OK. Current restricted directory is /\n'
	*resp* '230 OK. Current restricted directory is /'
	*cmd* 'PBSZ 0'
	*put* 'PBSZ 0\r\n'
	*get* '200 PBSZ=0\n'
	*resp* '200 PBSZ=0'
	*cmd* 'PROT P'
	*put* 'PROT P\r\n'
	*get* '200 Data protection level set to "private"\n'
	*resp* '200 Data protection level set to "private"'
	*cmd* 'MKD mydir'
	*put* 'MKD mydir\r\n'
	*get* '257 "mydir" : The directory was successfully created\n'
	*resp* '257 "mydir" : The directory was successfully created'
	*cmd* 'CWD mydir'
	*put* 'CWD mydir\r\n'
	*get* '250 OK. Current directory is /mydir\n'
	*resp* '250 OK. Current directory is /mydir'
	*cmd* 'TYPE A'
	*put* 'TYPE A\r\n'
	*get* '200 TYPE is now ASCII\n'
	*resp* '200 TYPE is now ASCII'
	*cmd* 'PASV'
	*put* 'PASV\r\n'
	*get* '227 Entering Passive Mode (8,8,8,8,8,8)\n'
	*resp* '227 Entering Passive Mode (8,8,8,8,8,8)'
	*cmd* 'MLSD'
	*put* 'MLSD\r\n'
	*get* '150 Accepted data connection\n'
	*resp* '150 Accepted data connection'
	Traceback (most recent call last):
	  File "c:\my_script.py", line 384, in run_ftps
		ftps.retrlines('MLSD')
	  File "c:\libs\Python36\lib\ftplib.py", line 485, in retrlines
		conn.unwrap()
	  File "C:\libs\Python36\lib\ssl.py", line 1051, in unwrap
		s = self._sslobj.unwrap()
	  File "C:\libs\Python36\lib\ssl.py", line 698, in unwrap
		return self._sslobj.shutdown()
	OSError: [Errno 0] Error

The same FTP command (LIST) works fine via filezilla.

The closest thing I can find with googling is this: https://bugs.python.org/msg253161 - and I'm not sure if it's related or relevant.

Short version: What does "OSError: [Errno 0] Error" actually mean, and how do I list my directory contents?