diff --git a/Lib/ftplib.py b/Lib/ftplib.py
index b64e45e..c75b317 100644
--- a/Lib/ftplib.py
+++ b/Lib/ftplib.py
@@ -71,6 +71,7 @@
 
 # Line terminators (we always output CRLF, but accept any of CRLF, CR, LF)
 CRLF = '\r\n'
+B_CRLF = b'\r\n'
 
 # The class itself
 class FTP:
@@ -472,9 +473,9 @@
         while 1:
             buf = fp.readline()
             if not buf: break
-            if buf[-2:] != CRLF:
-                if buf[-1] in CRLF: buf = buf[:-1]
-                buf = buf + CRLF
+            if buf[-2:] != B_CRLF:
+                if buf[-1] in B_CRLF: buf = buf[:-1]
+                buf = buf + B_CRLF
             conn.sendall(buf)
             if callback: callback(buf)
         conn.close()
diff --git a/Lib/test/test_ftplib.py b/Lib/test/test_ftplib.py
index 35e4746..10eabba 100644
--- a/Lib/test/test_ftplib.py
+++ b/Lib/test/test_ftplib.py
@@ -1,44 +1,412 @@
-import socket
-import threading
+"""Test script for ftplib module."""
+
+# Modified by Giampaolo Rodola' to test FTP class and IPv6 environment
+
 import ftplib
-import time
+import threading
+import asyncore
+import asynchat
+import socket
+import io
 
 from unittest import TestCase
 from test import support
+from test.support import HOST
 
-HOST = support.HOST
+# the dummy data returned by server over the data channel when
+# RETR, LIST and NLST commands are issued
+RETR_DATA = 'abcde12345\r\n' * 1000
+LIST_DATA = 'foo\r\nbar\r\n'
+NLST_DATA = 'foo\r\nbar\r\n'
 
-# This function sets the evt 3 times:
-#  1) when the connection is ready to be accepted.
-#  2) when it is safe for the caller to close the connection
-#  3) when we have closed the socket
-def server(evt, serv):
-    serv.listen(5)
 
-    # (1) Signal the caller that we are ready to accept the connection.
-    evt.set()
-    try:
-        conn, addr = serv.accept()
-    except socket.timeout:
-        pass
-    else:
-        conn.send(b"1 Hola mundo\n")
-        # (2) Signal the caller that it is safe to close the socket.
-        evt.set()
+class DummyDTPHandler(asynchat.async_chat):
+
+    def __init__(self, conn, baseclass):
+        asynchat.async_chat.__init__(self, conn)
+        self.baseclass = baseclass
+        self.baseclass.last_received_data = ''
+
+    def handle_read(self):
+        self.baseclass.last_received_data += self.recv(1024).decode('ascii')
+
+    def handle_close(self):
+        self.baseclass.push('226 transfer complete')
+        self.close()
+
+    def push(self, what):
+        super(DummyDTPHandler, self).push(what.encode('ascii'))
+
+
+class DummyFTPHandler(asynchat.async_chat):
+
+    def __init__(self, conn):
+        asynchat.async_chat.__init__(self, conn)
+        self.set_terminator(b"\r\n")
+        self.in_buffer = []
+        self.dtp = None
+        self.last_received_cmd = None
+        self.last_received_data = ''
+        self.next_response = ''
+        self.push('220 welcome')
+
+    def collect_incoming_data(self, data):
+        self.in_buffer.append(data)
+
+    def found_terminator(self):
+        line = b''.join(self.in_buffer).decode('ascii')
+        self.in_buffer = []
+        if self.next_response:
+            self.push(self.next_response)
+            self.next_response = ''
+        cmd = line.split(' ')[0].lower()
+        self.last_received_cmd = cmd
+        space = line.find(' ')
+        if space != -1:
+            arg = line[space + 1:]
+        else:
+            arg = ""
+        if hasattr(self, 'cmd_' + cmd):
+            method = getattr(self, 'cmd_' + cmd)
+            method(arg)
+        else:
+            self.push('550 command "%s" not understood.' %cmd)
+
+    def handle_error(self):
+        raise
+
+    def push(self, data):
+        asynchat.async_chat.push(self, data.encode('ascii') + b'\r\n')
+
+    def cmd_port(self, arg):
+        addr = list(map(int, arg.split(',')))
+        ip = '%d.%d.%d.%d' %tuple(addr[:4])
+        port = (addr[4] * 256) + addr[5]
+        s = socket.create_connection((ip, port), timeout=2)
+        self.dtp = DummyDTPHandler(s, baseclass=self)
+        self.push('200 active data connection established')
+
+    def cmd_pasv(self, arg):
+        sock = socket.socket()
+        sock.bind((self.socket.getsockname()[0], 0))
+        sock.listen(5)
+        sock.settimeout(2)
+        ip, port = sock.getsockname()[:2]
+        ip = ip.replace('.', ','); p1 = port / 256; p2 = port % 256
+        self.push('227 entering passive mode (%s,%d,%d)' %(ip, p1, p2))
+        conn, addr = sock.accept()
+        self.dtp = DummyDTPHandler(conn, baseclass=self)
+
+    def cmd_eprt(self, arg):
+        af, ip, port = arg.split(arg[0])[1:-1]
+        port = int(port)
+        s = socket.create_connection((ip, port), timeout=2)
+        self.dtp = DummyDTPHandler(s, baseclass=self)
+        self.push('200 active data connection established')
+
+    def cmd_epsv(self, arg):
+        sock = socket.socket(socket.AF_INET6)
+        sock.bind((self.socket.getsockname()[0], 0))
+        sock.listen(5)
+        sock.settimeout(2)
+        port = sock.getsockname()[1]
+        self.push('229 entering extended passive mode (|||%d|)' %port)
+        conn, addr = sock.accept()
+        self.dtp = DummyDTPHandler(conn, baseclass=self)
+
+    def cmd_echo(self, arg):
+        # sends back the received string (used by the test suite)
+        self.push(arg)
+
+    def cmd_user(self, arg):
+        self.push('331 username ok')
+
+    def cmd_pass(self, arg):
+        self.push('230 password ok')
+
+    def cmd_acct(self, arg):
+        self.push('230 acct ok')
+
+    def cmd_rnfr(self, arg):
+        self.push('350 rnfr ok')
+
+    def cmd_rnto(self, arg):
+        self.push('250 rnto ok')
+
+    def cmd_dele(self, arg):
+        self.push('250 dele ok')
+
+    def cmd_cwd(self, arg):
+        self.push('250 cwd ok')
+
+    def cmd_size(self, arg):
+        self.push('250 1000')
+
+    def cmd_mkd(self, arg):
+        self.push('257 "%s"' %arg)
+
+    def cmd_rmd(self, arg):
+        self.push('250 rmd ok')
+
+    def cmd_pwd(self, arg):
+        self.push('257 "pwd ok"')
+
+    def cmd_type(self, arg):
+        self.push('200 type ok')
+
+    def cmd_quit(self, arg):
+        self.push('221 quit ok')
+        self.close()
+
+    def cmd_stor(self, arg):
+        self.push('125 stor ok')
+
+    def cmd_retr(self, arg):
+        self.push('125 retr ok')
+        self.dtp.push(RETR_DATA)
+        self.dtp.close_when_done()
+
+    def cmd_list(self, arg):
+        self.push('125 list ok')
+        self.dtp.push(LIST_DATA)
+        self.dtp.close_when_done()
+
+    def cmd_nlst(self, arg):
+        self.push('125 nlst ok')
+        self.dtp.push(NLST_DATA)
+        self.dtp.close_when_done()
+
+
+class DummyFTPServer(asyncore.dispatcher, threading.Thread):
+
+    handler = DummyFTPHandler
+
+    def __init__(self, address, af=socket.AF_INET):
+        threading.Thread.__init__(self)
+        asyncore.dispatcher.__init__(self)
+        self.create_socket(af, socket.SOCK_STREAM)
+        self.bind(address)
+        self.listen(5)
+        self.active = False
+        self.active_lock = threading.Lock()
+        self.host, self.port = self.socket.getsockname()[:2]
+
+    def start(self):
+        assert not self.active
+        self.__flag = threading.Event()
+        threading.Thread.start(self)
+        self.__flag.wait()
+
+    def run(self):
+        self.active = True
+        self.__flag.set()
+        while self.active and asyncore.socket_map:
+            self.active_lock.acquire()
+            asyncore.loop(timeout=0.1, count=1)
+            self.active_lock.release()
+        asyncore.close_all(ignore_all=True)
+
+    def stop(self):
+        assert self.active
+        self.active = False
+        self.join()
+
+    def handle_accept(self):
+        conn, addr = self.accept()
+        self.handler = self.handler(conn)
+
+    def writable(self):
+        return 0
+
+    def handle_error(self):
+        raise
+
+
+class TestFTPClass(TestCase):
+
+    def setUp(self):
+        self.server = DummyFTPServer((HOST, 0))
+        self.server.start()
+        self.client = ftplib.FTP(timeout=2)
+        self.client.connect(self.server.host, self.server.port)
+
+    def tearDown(self):
+        self.client.close()
+        self.server.stop()
+
+    def test_getwelcome(self):
+        self.assertEqual(self.client.getwelcome(), '220 welcome')
+
+    def test_sanitize(self):
+        self.assertEqual(self.client.sanitize('foo'), repr('foo'))
+        self.assertEqual(self.client.sanitize('pass 12345'), repr('pass *****'))
+        self.assertEqual(self.client.sanitize('PASS 12345'), repr('PASS *****'))
+
+    def test_exceptions(self):
+        self.assertRaises(ftplib.error_temp, self.client.sendcmd, 'echo 400')
+        self.assertRaises(ftplib.error_temp, self.client.sendcmd, 'echo 499')
+        self.assertRaises(ftplib.error_perm, self.client.sendcmd, 'echo 500')
+        self.assertRaises(ftplib.error_perm, self.client.sendcmd, 'echo 599')
+        self.assertRaises(ftplib.error_proto, self.client.sendcmd, 'echo 999')
+
+    def test_all_errors(self):
+        exceptions = (ftplib.error_reply, ftplib.error_temp, ftplib.error_perm,
+                      ftplib.error_proto, ftplib.Error, IOError, EOFError)
+        for x in exceptions:
+            try:
+                raise x('exception not included in all_errors set')
+            except ftplib.all_errors:
+                pass
+
+    def test_set_pasv(self):
+        # passive mode is supposed to be enabled by default
+        self.assertTrue(self.client.passiveserver)
+        self.client.set_pasv(True)
+        self.assertTrue(self.client.passiveserver)
+        self.client.set_pasv(False)
+        self.assertFalse(self.client.passiveserver)
+
+    def test_voidcmd(self):
+        self.client.voidcmd('echo 200')
+        self.client.voidcmd('echo 299')
+        self.assertRaises(ftplib.error_reply, self.client.voidcmd, 'echo 199')
+        self.assertRaises(ftplib.error_reply, self.client.voidcmd, 'echo 300')
+
+    def test_login(self):
+        self.client.login()
+
+    def test_acct(self):
+        self.client.acct('passwd')
+
+    def test_rename(self):
+        self.client.rename('a', 'b')
+        self.server.handler.next_response = '200'
+        self.assertRaises(ftplib.error_reply, self.client.rename, 'a', 'b')
+
+    def test_delete(self):
+        self.client.delete('foo')
+        self.server.handler.next_response = '199'
+        self.assertRaises(ftplib.error_reply, self.client.delete, 'foo')
+
+    def test_size(self):
+        self.client.size('foo')
+
+    def test_mkd(self):
+        dir = self.client.mkd('/foo')
+        self.assertEqual(dir, '/foo')
+
+    def test_rmd(self):
+        self.client.rmd('foo')
+
+    def test_pwd(self):
+        dir = self.client.pwd()
+        self.assertEqual(dir, 'pwd ok')
+
+    def test_quit(self):
+        self.assertEqual(self.client.quit(), '221 quit ok')
+        # Ensure the connection gets closed; sock attribute should be None
+        self.assertEqual(self.client.sock, None)
+
+    def test_retrbinary(self):
+        def callback(data):
+            received.append(data.decode('ascii'))
+        received = []
+        self.client.retrbinary('retr', callback)
+        self.assertEqual(''.join(received), RETR_DATA)
+
+    def test_retrlines(self):
+        received = []
+        self.client.retrlines('retr', received.append)
+        self.assertEqual(''.join(received), RETR_DATA.replace('\r\n', ''))
+
+    def test_storbinary(self):
+        f = io.BytesIO(RETR_DATA.encode('ascii'))
+        self.client.storbinary('stor', f)
+        self.assertEqual(self.server.handler.last_received_data, RETR_DATA)
+        # test new callback arg
+        flag = []
+        f.seek(0)
+        self.client.storbinary('stor', f, callback=lambda x: flag.append(None))
+        self.assertTrue(flag)
+
+    def test_storlines(self):
+        f = io.BytesIO(RETR_DATA.replace('\r\n', '\n').encode('ascii'))
+        self.client.storlines('stor', f)
+        self.assertEqual(self.server.handler.last_received_data, RETR_DATA)
+        # test new callback arg
+        flag = []
+        f.seek(0)
+        self.client.storlines('stor foo', f, callback=lambda x: flag.append(None))
+        self.assertTrue(flag)
+
+    def test_nlst(self):
+        self.client.nlst()
+        self.assertEqual(self.client.nlst(), NLST_DATA.split('\r\n')[:-1])
+
+    def test_dir(self):
+        l = []
+        self.client.dir(lambda x: l.append(x))
+        self.assertEqual(''.join(l), LIST_DATA.replace('\r\n', ''))
+
+    def Xtest_makeport(self):
+        self.client.makeport()
+        # IPv4 is in use, just make sure send_eprt has not been used
+        self.assertEqual(self.server.handler.last_received_cmd, 'port')
+
+    def test_makepasv(self):
+        host, port = self.client.makepasv()
+        conn = socket.create_connection((host, port), 2)
         conn.close()
-    finally:
-        serv.close()
-        # (3) Signal the caller that we are done.
-        evt.set()
+        # IPv4 is in use, just make sure send_epsv has not been used
+        self.assertEqual(self.server.handler.last_received_cmd, 'pasv')
 
-class GeneralTests(TestCase):
+
+class TestIPv6Environment(TestCase):
+
+    def setUp(self):
+        self.server = DummyFTPServer((HOST, 0), af=socket.AF_INET6)
+        self.server.start()
+        self.client = ftplib.FTP()
+        self.client.connect(self.server.host, self.server.port)
+
+    def tearDown(self):
+        self.client.close()
+        self.server.stop()
+
+    def test_af(self):
+        self.assertEqual(self.client.af, socket.AF_INET6)
+
+    def test_makeport(self):
+        self.client.makeport()
+        self.assertEqual(self.server.handler.last_received_cmd, 'eprt')
+
+    def test_makepasv(self):
+        host, port = self.client.makepasv()
+        conn = socket.create_connection((host, port), 2)
+        conn.close()
+        self.assertEqual(self.server.handler.last_received_cmd, 'epsv')
+
+    def test_transfer(self):
+        def retr():
+            def callback(data):
+                received.append(data.decode('ascii'))
+            received = []
+            self.client.retrbinary('retr', callback)
+            self.assertEqual(''.join(received), RETR_DATA)
+        self.client.set_pasv(True)
+        retr()
+        self.client.set_pasv(False)
+        retr()
+
+
+class TestTimeouts(TestCase):
 
     def setUp(self):
         self.evt = threading.Event()
         self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         self.sock.settimeout(3)
         self.port = support.bind_port(self.sock)
-        threading.Thread(target=server, args=(self.evt,self.sock)).start()
+        threading.Thread(target=self.server, args=(self.evt,self.sock)).start()
         # Wait for the server to be ready.
         self.evt.wait()
         self.evt.clear()
@@ -47,14 +415,27 @@
     def tearDown(self):
         self.evt.wait()
 
-    def testBasic(self):
-        # do nothing
-        ftplib.FTP()
-
-        # connects
-        ftp = ftplib.FTP(HOST)
-        self.evt.wait()
-        ftp.close()
+    def server(self, evt, serv):
+        # This method sets the evt 3 times:
+        #  1) when the connection is ready to be accepted.
+        #  2) when it is safe for the caller to close the connection
+        #  3) when we have closed the socket
+        serv.listen(5)
+        # (1) Signal the caller that we are ready to accept the connection.
+        evt.set()
+        try:
+            conn, addr = serv.accept()
+        except socket.timeout:
+            pass
+        else:
+            conn.send(b"1 Hola mundo\n")
+            # (2) Signal the caller that it is safe to close the socket.
+            evt.set()
+            conn.close()
+        finally:
+            serv.close()
+            # (3) Signal the caller that we are done.
+            evt.set()
 
     def testTimeoutDefault(self):
         # default -- use global socket timeout
@@ -110,8 +491,21 @@
         ftp.close()
 
 
-def test_main(verbose=None):
-    support.run_unittest(GeneralTests)
+def test_main():
+    tests = [TestFTPClass, TestTimeouts]
+    if socket.has_ipv6:
+        try:
+            DummyFTPServer((HOST, 0), af=socket.AF_INET6)
+        except socket.error:
+            pass
+        else:
+            tests.append(TestIPv6Environment)
+    thread_info = support.threading_setup()
+    try:
+        support.run_unittest(*tests)
+    finally:
+        support.threading_cleanup(*thread_info)
+
 
 if __name__ == '__main__':
     test_main()