From 63e869f4e4ba3fdfd6e6bc3715349519215c73f7 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Sat, 20 May 2017 13:44:08 -0400
Subject: [PATCH 01/14] options: Report redefinition errors when underscores
 are used

Fixes #2020
---
 tornado/options.py           |  6 +++---
 tornado/test/options_test.py | 20 +++++++++++++++++++-
 tornado/test/util.py         | 13 +++++++++++++
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/tornado/options.py b/tornado/options.py
index 0a72cc65..707fbd35 100644
--- a/tornado/options.py
+++ b/tornado/options.py
@@ -223,9 +223,10 @@ class OptionParser(object):
         override options set earlier on the command line, but can be overridden
         by later flags.
         """
-        if name in self._options:
+        normalized = self._normalize_name(name)
+        if normalized in self._options:
             raise Error("Option %r already defined in %s" %
-                        (name, self._options[name].file_name))
+                        (normalized, self._options[normalized].file_name))
         frame = sys._getframe(0)
         options_file = frame.f_code.co_filename
 
@@ -247,7 +248,6 @@ class OptionParser(object):
             group_name = group
         else:
             group_name = file_name
-        normalized = self._normalize_name(name)
         option = _Option(name, file_name=file_name,
                          default=default, type=type, help=help,
                          metavar=metavar, multiple=multiple,
diff --git a/tornado/test/options_test.py b/tornado/test/options_test.py
index bafeea6f..1a0ac8fb 100644
--- a/tornado/test/options_test.py
+++ b/tornado/test/options_test.py
@@ -7,7 +7,7 @@ import sys
 
 from tornado.options import OptionParser, Error
 from tornado.util import basestring_type, PY3
-from tornado.test.util import unittest
+from tornado.test.util import unittest, subTest
 
 if PY3:
     from io import StringIO
@@ -232,6 +232,24 @@ class OptionsTest(unittest.TestCase):
         self.assertRegexpMatches(str(cm.exception),
                                  'Option.*foo.*already defined')
 
+    def test_error_redefine_underscore(self):
+        # Ensure that the dash/underscore normalization doesn't
+        # interfere with the redefinition error.
+        tests = [
+            ('foo-bar', 'foo-bar'),
+            ('foo_bar', 'foo_bar'),
+            ('foo-bar', 'foo_bar'),
+            ('foo_bar', 'foo-bar'),
+            ]
+        for a, b in tests:
+            with subTest(self, a=a, b=b):
+                options = OptionParser()
+                options.define(a)
+                with self.assertRaises(Error) as cm:
+                    options.define(b)
+                self.assertRegexpMatches(str(cm.exception),
+                                         'Option.*foo.bar.*already defined')
+
     def test_dash_underscore_cli(self):
         # Dashes and underscores should be interchangeable.
         for defined_name in ['foo-bar', 'foo_bar']:
diff --git a/tornado/test/util.py b/tornado/test/util.py
index 6c032da6..5f534e84 100644
--- a/tornado/test/util.py
+++ b/tornado/test/util.py
@@ -1,5 +1,6 @@
 from __future__ import absolute_import, division, print_function
 
+import contextlib
 import os
 import platform
 import socket
@@ -94,3 +95,15 @@ def is_coverage_running():
         except AttributeError:
             return False
     return mod.startswith('coverage')
+
+
+def subTest(test, *args, **kwargs):
+    """Compatibility shim for unittest.TestCase.subTest.
+
+    Usage: ``with tornado.test.util.subTest(self, x=x):``
+    """
+    try:
+        subTest = test.subTest  # py34+
+    except AttributeError:
+        subTest = contextlib.contextmanager(lambda *a, **kw: (yield))
+    return subTest(*args, **kwargs)

From d67d4916a362a57fd05f8f73851efe6fe1b407a1 Mon Sep 17 00:00:00 2001
From: Sebastien Boving <seb@google.com>
Date: Tue, 27 Jun 2017 09:35:55 -0700
Subject: [PATCH 02/14] Do not send/expect Content-Length on 1xx

---
 tornado/http1connection.py | 7 ++++---
 tornado/web.py             | 3 ++-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/tornado/http1connection.py b/tornado/http1connection.py
index 53744ece..20d98e43 100644
--- a/tornado/http1connection.py
+++ b/tornado/http1connection.py
@@ -349,10 +349,11 @@ class HTTP1Connection(httputil.HTTPConnection):
                 # self._request_start_line.version or
                 # start_line.version?
                 self._request_start_line.version == 'HTTP/1.1' and
-                # 304 responses have no body (not even a zero-length body), and so
-                # should not have either Content-Length or Transfer-Encoding.
-                # headers.
+                # 1xx, 204 and 304 responses have no body (not even a zero-length
+                # body), and so should not have either Content-Length or
+                # Transfer-Encoding headers.
                 start_line.code not in (204, 304) and
+                (start_line.code < 100 or start_line.code >= 200) and
                 # No need to chunk the output if a Content-Length is specified.
                 'Content-Length' not in headers and
                 # Applications are discouraged from touching Transfer-Encoding,
diff --git a/tornado/web.py b/tornado/web.py
index d79889fa..338fe0f0 100644
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -977,7 +977,8 @@ class RequestHandler(object):
             if self._status_code in (204, 304):
                 assert not self._write_buffer, "Cannot send body with %s" % self._status_code
                 self._clear_headers_for_304()
-            elif "Content-Length" not in self._headers:
+            elif ("Content-Length" not in self._headers and
+                  (self._status_code < 100 or self._status_code >= 200)):
                 content_length = sum(len(part) for part in self._write_buffer)
                 self.set_header("Content-Length", content_length)
 

From 7a23296100b7a796ae42df9b0c8e250b9a7a5cf1 Mon Sep 17 00:00:00 2001
From: Sebastien Boving <seb@google.com>
Date: Wed, 5 Jul 2017 10:04:33 -0700
Subject: [PATCH 03/14] Handle 1xx's along 204/304's

---
 tornado/web.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tornado/web.py b/tornado/web.py
index 338fe0f0..e8d102b5 100644
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -974,11 +974,11 @@ class RequestHandler(object):
                 if self.check_etag_header():
                     self._write_buffer = []
                     self.set_status(304)
-            if self._status_code in (204, 304):
+            if (self._status_code in (204, 304) or
+                (self._status_code >= 100 and self._status_code < 200)):
                 assert not self._write_buffer, "Cannot send body with %s" % self._status_code
                 self._clear_headers_for_304()
-            elif ("Content-Length" not in self._headers and
-                  (self._status_code < 100 or self._status_code >= 200)):
+            elif "Content-Length" not in self._headers:
                 content_length = sum(len(part) for part in self._write_buffer)
                 self.set_header("Content-Length", content_length)
 

From 8851634dca72d76df847947a40603681b27de44e Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Tue, 11 Jul 2017 12:07:34 +0200
Subject: [PATCH 04/14] cast curl debug messages to str

since they come in as bytes on Python 3
---
 tornado/curl_httpclient.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tornado/curl_httpclient.py b/tornado/curl_httpclient.py
index eef4a17a..8558d65c 100644
--- a/tornado/curl_httpclient.py
+++ b/tornado/curl_httpclient.py
@@ -493,6 +493,7 @@ class CurlAsyncHTTPClient(AsyncHTTPClient):
 
     def _curl_debug(self, debug_type, debug_msg):
         debug_types = ('I', '<', '>', '<', '>')
+        debug_msg = native_str(debug_msg)
         if debug_type == 0:
             curl_log.debug('%s', debug_msg.strip())
         elif debug_type in (1, 2):

From b7f9f0b9116ddb09915e7e783fb9cbc82546b301 Mon Sep 17 00:00:00 2001
From: Jungkook Park <pjknkda@gmail.com>
Date: Fri, 22 Sep 2017 02:14:51 +0900
Subject: [PATCH 05/14] fix websocket handshake failure causes an exception

---
 tornado/test/websocket_test.py | 7 +++++++
 tornado/websocket.py           | 8 ++++++++
 2 files changed, 15 insertions(+)

diff --git a/tornado/test/websocket_test.py b/tornado/test/websocket_test.py
index d47a74e6..95a5ecd4 100644
--- a/tornado/test/websocket_test.py
+++ b/tornado/test/websocket_test.py
@@ -189,6 +189,13 @@ class WebSocketTest(WebSocketBaseTestCase):
         response = self.fetch('/echo')
         self.assertEqual(response.code, 400)
 
+    def test_missing_websocket_key(self):
+        response = self.fetch('/echo',
+                              headers={'Connection': 'Upgrade',
+                                       'Upgrade': 'WebSocket',
+                                       'Sec-WebSocket-Version': '13'})
+        self.assertEqual(response.code, 400)
+
     def test_bad_websocket_version(self):
         response = self.fetch('/echo',
                               headers={'Connection': 'Upgrade',
diff --git a/tornado/websocket.py b/tornado/websocket.py
index 69437ee4..0e9d339f 100644
--- a/tornado/websocket.py
+++ b/tornado/websocket.py
@@ -616,6 +616,14 @@ class WebSocketProtocol13(WebSocketProtocol):
     def accept_connection(self):
         try:
             self._handle_websocket_headers()
+        except ValueError:
+            self.handler.set_status(400)
+            log_msg = "Missing/Invalid WebSocket headers"
+            self.handler.finish(log_msg)
+            gen_log.debug(log_msg)
+            return
+
+        try:
             self._accept_connection()
         except ValueError:
             gen_log.debug("Malformed WebSocket request received",

From fdc577f15f329303d2d5b3fdb6eb811eb6f0caf2 Mon Sep 17 00:00:00 2001
From: Antoine Pitrou <antoine@python.org>
Date: Sat, 21 Oct 2017 20:47:29 +0200
Subject: [PATCH 06/14] Release memoryviews explicitly

See https://github.com/tornadoweb/tornado/pull/2008 for reasons why this
might be necessary.
---
 tornado/iostream.py | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/tornado/iostream.py b/tornado/iostream.py
index a1619c49..784ef5e1 100644
--- a/tornado/iostream.py
+++ b/tornado/iostream.py
@@ -83,6 +83,15 @@ if hasattr(errno, "WSAEINPROGRESS"):
     _ERRNO_INPROGRESS += (errno.WSAEINPROGRESS,)  # type: ignore
 
 _WINDOWS = sys.platform.startswith('win')
+_PY3 = sys.version_info[0] >= 3
+
+if _PY3:
+    # We'd like to release memoryviews explicitly, see
+    # https://github.com/tornadoweb/tornado/pull/2008
+    _release_memoryview = memoryview.release
+else:
+    def _release_memoryview(m):
+        pass
 
 
 class StreamClosedError(IOError):
@@ -858,8 +867,14 @@ class BaseIOStream(object):
                     size = 128 * 1024
                 else:
                     size = self._write_buffer_size
-                num_bytes = self.write_to_fd(
-                    memoryview(self._write_buffer)[start:start + size])
+                mem = memoryview(self._write_buffer)
+                mem2 = mem[start:start + size]
+                try:
+                    num_bytes = self.write_to_fd(mem2)
+                finally:
+                    _release_memoryview(mem2)
+                    _release_memoryview(mem)
+                    del mem, mem2
                 if num_bytes == 0:
                     self._got_empty_write(size)
                     break
@@ -907,9 +922,14 @@ class BaseIOStream(object):
             return b""
         assert loc <= self._read_buffer_size
         # Slice the bytearray buffer into bytes, without intermediate copying
-        b = (memoryview(self._read_buffer)
-             [self._read_buffer_pos:self._read_buffer_pos + loc]
-             ).tobytes()
+        mem = memoryview(self._read_buffer)
+        mem2 = mem[self._read_buffer_pos:self._read_buffer_pos + loc]
+        try:
+            b = mem2.tobytes()
+        finally:
+            _release_memoryview(mem2)
+            _release_memoryview(mem)
+            del mem, mem2
         self._read_buffer_pos += loc
         self._read_buffer_size -= loc
         # Amortized O(1) shrink

From a91106195905a9cfb1c40cb2cdcc1c94bf46cde9 Mon Sep 17 00:00:00 2001
From: Antoine Pitrou <antoine@python.org>
Date: Sat, 21 Oct 2017 22:05:19 +0200
Subject: [PATCH 07/14] Don't keep any reference to memoryviews

See https://github.com/tornadoweb/tornado/pull/2008 for reasons
why this might be necessary.
---
 tornado/iostream.py | 48 ++++++++++++++++++++-------------------------
 1 file changed, 21 insertions(+), 27 deletions(-)

diff --git a/tornado/iostream.py b/tornado/iostream.py
index 784ef5e1..639ed508 100644
--- a/tornado/iostream.py
+++ b/tornado/iostream.py
@@ -83,15 +83,6 @@ if hasattr(errno, "WSAEINPROGRESS"):
     _ERRNO_INPROGRESS += (errno.WSAEINPROGRESS,)  # type: ignore
 
 _WINDOWS = sys.platform.startswith('win')
-_PY3 = sys.version_info[0] >= 3
-
-if _PY3:
-    # We'd like to release memoryviews explicitly, see
-    # https://github.com/tornadoweb/tornado/pull/2008
-    _release_memoryview = memoryview.release
-else:
-    def _release_memoryview(m):
-        pass
 
 
 class StreamClosedError(IOError):
@@ -867,14 +858,8 @@ class BaseIOStream(object):
                     size = 128 * 1024
                 else:
                     size = self._write_buffer_size
-                mem = memoryview(self._write_buffer)
-                mem2 = mem[start:start + size]
-                try:
-                    num_bytes = self.write_to_fd(mem2)
-                finally:
-                    _release_memoryview(mem2)
-                    _release_memoryview(mem)
-                    del mem, mem2
+                num_bytes = self.write_to_fd(
+                    memoryview(self._write_buffer)[start:start + size])
                 if num_bytes == 0:
                     self._got_empty_write(size)
                     break
@@ -922,14 +907,9 @@ class BaseIOStream(object):
             return b""
         assert loc <= self._read_buffer_size
         # Slice the bytearray buffer into bytes, without intermediate copying
-        mem = memoryview(self._read_buffer)
-        mem2 = mem[self._read_buffer_pos:self._read_buffer_pos + loc]
-        try:
-            b = mem2.tobytes()
-        finally:
-            _release_memoryview(mem2)
-            _release_memoryview(mem)
-            del mem, mem2
+        b = (memoryview(self._read_buffer)
+             [self._read_buffer_pos:self._read_buffer_pos + loc]
+             ).tobytes()
         self._read_buffer_pos += loc
         self._read_buffer_size -= loc
         # Amortized O(1) shrink
@@ -1081,7 +1061,12 @@ class IOStream(BaseIOStream):
         return chunk
 
     def write_to_fd(self, data):
-        return self.socket.send(data)
+        try:
+            return self.socket.send(data)
+        finally:
+            # Avoid keeping to data, which can be a memoryview.
+            # See https://github.com/tornadoweb/tornado/pull/2008
+            del data
 
     def connect(self, address, callback=None, server_hostname=None):
         """Connects the socket to a remote address without blocking.
@@ -1491,6 +1476,10 @@ class SSLIOStream(IOStream):
                 # simply return 0 bytes written.
                 return 0
             raise
+        finally:
+            # Avoid keeping to data, which can be a memoryview.
+            # See https://github.com/tornadoweb/tornado/pull/2008
+            del data
 
     def read_from_fd(self):
         if self._ssl_accepting:
@@ -1548,7 +1537,12 @@ class PipeIOStream(BaseIOStream):
         os.close(self.fd)
 
     def write_to_fd(self, data):
-        return os.write(self.fd, data)
+        try:
+            return os.write(self.fd, data)
+        finally:
+            # Avoid keeping to data, which can be a memoryview.
+            # See https://github.com/tornadoweb/tornado/pull/2008
+            del data
 
     def read_from_fd(self):
         try:

From 17210e382571b87eb1bd80972a79c9f2f4e92adc Mon Sep 17 00:00:00 2001
From: Pierce Lopez <pierce.lopez@gmail.com>
Date: Mon, 25 Dec 2017 22:11:26 -0500
Subject: [PATCH 08/14] http: read final crlf of chunked requests

otherwise a subsequent request on the same connection
will fail to be parsed

thanks to @eeelin for the bug report
---
 tornado/http1connection.py      | 3 +++
 tornado/test/httpserver_test.py | 7 +++++--
 tornado/test/web_test.py        | 2 +-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/tornado/http1connection.py b/tornado/http1connection.py
index 20d98e43..9b33c94e 100644
--- a/tornado/http1connection.py
+++ b/tornado/http1connection.py
@@ -593,6 +593,9 @@ class HTTP1Connection(httputil.HTTPConnection):
             chunk_len = yield self.stream.read_until(b"\r\n", max_bytes=64)
             chunk_len = int(chunk_len.strip(), 16)
             if chunk_len == 0:
+                crlf = yield self.stream.read_bytes(2)
+                if crlf != b'\r\n':
+                    raise HTTPInputError("improperly terminated chunked request")
                 return
             total_size += chunk_len
             if total_size > self._max_body_size:
diff --git a/tornado/test/httpserver_test.py b/tornado/test/httpserver_test.py
index 11cb7231..59eb6fd1 100644
--- a/tornado/test/httpserver_test.py
+++ b/tornado/test/httpserver_test.py
@@ -786,9 +786,12 @@ class KeepAliveTest(AsyncHTTPTestCase):
     def test_keepalive_chunked(self):
         self.http_version = b'HTTP/1.0'
         self.connect()
-        self.stream.write(b'POST / HTTP/1.0\r\nConnection: keep-alive\r\n'
+        self.stream.write(b'POST / HTTP/1.0\r\n'
+                          b'Connection: keep-alive\r\n'
                           b'Transfer-Encoding: chunked\r\n'
-                          b'\r\n0\r\n')
+                          b'\r\n'
+                          b'0\r\n'
+                          b'\r\n')
         self.read_response()
         self.assertEqual(self.headers['Connection'], 'Keep-Alive')
         self.stream.write(b'GET / HTTP/1.0\r\nConnection: keep-alive\r\n\r\n')
diff --git a/tornado/test/web_test.py b/tornado/test/web_test.py
index d79ea52c..d83446e4 100644
--- a/tornado/test/web_test.py
+++ b/tornado/test/web_test.py
@@ -2134,7 +2134,7 @@ class StreamingRequestBodyTest(WebTestCase):
         stream.write(b"4\r\nqwer\r\n")
         data = yield self.data
         self.assertEquals(data, b"qwer")
-        stream.write(b"0\r\n")
+        stream.write(b"0\r\n\r\n")
         yield self.finished
         data = yield gen.Task(stream.read_until_close)
         # This would ideally use an HTTP1Connection to read the response.

From f1f7d2ef8a5428ad64877191a4efafa47b9fe752 Mon Sep 17 00:00:00 2001
From: Pierce Lopez <pierce.lopez@gmail.com>
Date: Sat, 30 Dec 2017 18:34:32 -0500
Subject: [PATCH 09/14] fix HTTPInputError reference for improperly terminated
 chunked request

bug introduced in #2225
---
 tornado/http1connection.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tornado/http1connection.py b/tornado/http1connection.py
index 9b33c94e..32bed6c9 100644
--- a/tornado/http1connection.py
+++ b/tornado/http1connection.py
@@ -595,7 +595,7 @@ class HTTP1Connection(httputil.HTTPConnection):
             if chunk_len == 0:
                 crlf = yield self.stream.read_bytes(2)
                 if crlf != b'\r\n':
-                    raise HTTPInputError("improperly terminated chunked request")
+                    raise httputil.HTTPInputError("improperly terminated chunked request")
                 return
             total_size += chunk_len
             if total_size > self._max_body_size:

From 84bb2e285e15415bb86cbdf2326b19f0debb80fd Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Sun, 5 Nov 2017 10:32:10 -0500
Subject: [PATCH 10/14] testing: Connect to 127.0.0.1 instead of localhost

The servers used in tests are only listening for ipv4, not ipv6
(to avoid spurious firewall prompts on macos). In what is apparently
a recent macos change, connecting to `localhost` when the ipv6 port
is unbound now incurs a 200ms delay, slowing a full test run down
by a factor of 20.
---
 tornado/test/simple_httpclient_test.py | 2 +-
 tornado/test/web_test.py               | 2 +-
 tornado/testing.py                     | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tornado/test/simple_httpclient_test.py b/tornado/test/simple_httpclient_test.py
index 02d57c5f..451942d2 100644
--- a/tornado/test/simple_httpclient_test.py
+++ b/tornado/test/simple_httpclient_test.py
@@ -327,7 +327,7 @@ class SimpleHTTPClientTestMixin(object):
         self.assertNotIn("Content-Length", response.headers)
 
     def test_host_header(self):
-        host_re = re.compile(b"^localhost:[0-9]+$")
+        host_re = re.compile(b"^127.0.0.1:[0-9]+$")
         response = self.fetch("/host_echo")
         self.assertTrue(host_re.match(response.body))
 
diff --git a/tornado/test/web_test.py b/tornado/test/web_test.py
index d83446e4..013c2ac2 100644
--- a/tornado/test/web_test.py
+++ b/tornado/test/web_test.py
@@ -356,7 +356,7 @@ class AuthRedirectTest(WebTestCase):
         response = self.wait()
         self.assertEqual(response.code, 302)
         self.assertTrue(re.match(
-            'http://example.com/login\?next=http%3A%2F%2Flocalhost%3A[0-9]+%2Fabsolute',
+            'http://example.com/login\?next=http%3A%2F%2F127.0.0.1%3A[0-9]+%2Fabsolute',
             response.headers['Location']), response.headers['Location'])
 
 
diff --git a/tornado/testing.py b/tornado/testing.py
index 74d04b60..82a3b937 100644
--- a/tornado/testing.py
+++ b/tornado/testing.py
@@ -423,7 +423,7 @@ class AsyncHTTPTestCase(AsyncTestCase):
 
     def get_url(self, path):
         """Returns an absolute url for the given path on the test server."""
-        return '%s://localhost:%s%s' % (self.get_protocol(),
+        return '%s://127.0.0.1:%s%s' % (self.get_protocol(),
                                         self.get_http_port(), path)
 
     def tearDown(self):

From b525e423c3d143f3e67dba26fea2f1103b9bb6d4 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Sun, 5 Nov 2017 10:38:03 -0500
Subject: [PATCH 11/14] test: More robust ipv6 detection

There are many ways ipv6 can be disabled or broken (and it just
stopped working on travis-ci), so instead of checking flags like
socket.has_ipv6, attempt to actually bind to an ipv6 address.

Closes #2185
---
 tornado/test/simple_httpclient_test.py | 13 +++----------
 tornado/test/util.py                   | 23 ++++++++++++++++++++---
 2 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/tornado/test/simple_httpclient_test.py b/tornado/test/simple_httpclient_test.py
index 451942d2..0e75e530 100644
--- a/tornado/test/simple_httpclient_test.py
+++ b/tornado/test/simple_httpclient_test.py
@@ -272,16 +272,9 @@ class SimpleHTTPClientTestMixin(object):
 
     @skipIfNoIPv6
     def test_ipv6(self):
-        try:
-            [sock] = bind_sockets(None, '::1', family=socket.AF_INET6)
-            port = sock.getsockname()[1]
-            self.http_server.add_socket(sock)
-        except socket.gaierror as e:
-            if e.args[0] == socket.EAI_ADDRFAMILY:
-                # python supports ipv6, but it's not configured on the network
-                # interface, so skip this test.
-                return
-            raise
+        [sock] = bind_sockets(None, '::1', family=socket.AF_INET6)
+        port = sock.getsockname()[1]
+        self.http_server.add_socket(sock)
         url = '%s://[::1]:%d/hello' % (self.get_protocol(), port)
 
         # ipv6 is currently enabled by default but can be disabled
diff --git a/tornado/test/util.py b/tornado/test/util.py
index 5f534e84..7958d92b 100644
--- a/tornado/test/util.py
+++ b/tornado/test/util.py
@@ -35,15 +35,32 @@ skipOnAppEngine = unittest.skipIf('APPENGINE_RUNTIME' in os.environ,
 skipIfNoNetwork = unittest.skipIf('NO_NETWORK' in os.environ,
                                   'network access disabled')
 
-skipIfNoIPv6 = unittest.skipIf(not socket.has_ipv6, 'ipv6 support not present')
-
-
 skipBefore33 = unittest.skipIf(sys.version_info < (3, 3), 'PEP 380 (yield from) not available')
 skipBefore35 = unittest.skipIf(sys.version_info < (3, 5), 'PEP 492 (async/await) not available')
 skipNotCPython = unittest.skipIf(platform.python_implementation() != 'CPython',
                                  'Not CPython implementation')
 
 
+def _detect_ipv6():
+    if not socket.has_ipv6:
+        # socket.has_ipv6 check reports whether ipv6 was present at compile
+        # time. It's usually true even when ipv6 doesn't work for other reasons.
+        return False
+    sock = None
+    try:
+        sock = socket.socket(socket.AF_INET6)
+        sock.bind(('::1', 0))
+    except socket.error:
+        return False
+    finally:
+        if sock is not None:
+            sock.close()
+    return True
+
+
+skipIfNoIPv6 = unittest.skipIf(not _detect_ipv6(), 'ipv6 support not present')
+
+
 def refusing_port():
     """Returns a local port number that will refuse all connections.
 

From 716ab7d509a44bb00c5cbfec37ad3d16cdcd2618 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Fri, 5 Jan 2018 09:59:00 -0500
Subject: [PATCH 12/14] Update travis-ci python versions to match master.

2.7.8 is no longer available and "pypy3" is old and has
other issues.
---
 .travis.yml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 4b2ac2bc..e3b33c04 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,6 @@
 # https://travis-ci.org/tornadoweb/tornado
 language: python
 python:
-    - 2.7.8
     - 2.7
     - pypy
     - 3.3
@@ -9,7 +8,7 @@ python:
     - 3.5
     - 3.6
     - nightly
-    - pypy3
+    - pypy3.5-5.8.0
 
 install:
     - if [[ $TRAVIS_PYTHON_VERSION == 2* ]]; then travis_retry pip install futures mock monotonic trollius; fi

From 7be09af39047c8e528946e3dea10f1309be78953 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Sun, 27 Aug 2017 22:38:14 -0400
Subject: [PATCH 13/14] Get tests passing on latest version of pypy3

---
 tornado/test/iostream_test.py | 6 ++++--
 tornado/test/util.py          | 8 ++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/tornado/test/iostream_test.py b/tornado/test/iostream_test.py
index 91bc7bf6..56fffe60 100644
--- a/tornado/test/iostream_test.py
+++ b/tornado/test/iostream_test.py
@@ -9,7 +9,7 @@ from tornado.netutil import ssl_wrap_socket
 from tornado.stack_context import NullContext
 from tornado.tcpserver import TCPServer
 from tornado.testing import AsyncHTTPTestCase, AsyncHTTPSTestCase, AsyncTestCase, bind_unused_port, ExpectLog, gen_test
-from tornado.test.util import unittest, skipIfNonUnix, refusing_port
+from tornado.test.util import unittest, skipIfNonUnix, refusing_port, skipPypy3V58
 from tornado.web import RequestHandler, Application
 import errno
 import logging
@@ -539,6 +539,7 @@ class TestIOStreamMixin(object):
             client.close()
 
     @skipIfNonUnix
+    @skipPypy3V58
     def test_inline_read_error(self):
         # An error on an inline read is raised without logging (on the
         # assumption that it will eventually be noticed or logged further
@@ -557,6 +558,7 @@ class TestIOStreamMixin(object):
             server.close()
             client.close()
 
+    @skipPypy3V58
     def test_async_read_error_logging(self):
         # Socket errors on asynchronous reads should be logged (but only
         # once).
@@ -993,7 +995,7 @@ class TestIOStreamStartTLS(AsyncTestCase):
         server_future = self.server_start_tls(_server_ssl_options())
         client_future = self.client_start_tls(
             ssl.create_default_context(),
-            server_hostname=b'127.0.0.1')
+            server_hostname='127.0.0.1')
         with ExpectLog(gen_log, "SSL Error"):
             with self.assertRaises(ssl.SSLError):
                 # The client fails to connect with an SSL error.
diff --git a/tornado/test/util.py b/tornado/test/util.py
index 7958d92b..90a9c7b8 100644
--- a/tornado/test/util.py
+++ b/tornado/test/util.py
@@ -40,6 +40,14 @@ skipBefore35 = unittest.skipIf(sys.version_info < (3, 5), 'PEP 492 (async/await)
 skipNotCPython = unittest.skipIf(platform.python_implementation() != 'CPython',
                                  'Not CPython implementation')
 
+# Used for tests affected by
+# https://bitbucket.org/pypy/pypy/issues/2616/incomplete-error-handling-in
+# TODO: remove this after pypy3 5.8 is obsolete.
+skipPypy3V58 = unittest.skipIf(platform.python_implementation() == 'PyPy' and
+                               sys.version_info > (3,) and
+                               sys.pypy_version_info < (5, 9),
+                               'pypy3 5.8 has buggy ssl module')
+
 
 def _detect_ipv6():
     if not socket.has_ipv6:

From 09c63c55e05674a51f2cce86d5fda090843afb3a Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Thu, 4 Jan 2018 22:44:17 -0500
Subject: [PATCH 14/14] Release notes for 4.5.3

---
 docs/releases.rst        |  1 +
 docs/releases/v4.5.3.rst | 49 ++++++++++++++++++++++++++++++++++++++++
 setup.py                 |  2 +-
 tornado/__init__.py      |  4 ++--
 4 files changed, 53 insertions(+), 3 deletions(-)
 create mode 100644 docs/releases/v4.5.3.rst

diff --git a/docs/releases.rst b/docs/releases.rst
index 3a9ef777..128c7603 100644
--- a/docs/releases.rst
+++ b/docs/releases.rst
@@ -4,6 +4,7 @@ Release notes
 .. toctree::
    :maxdepth: 2
 
+   releases/v4.5.3
    releases/v4.5.2
    releases/v4.5.1
    releases/v4.5.0
diff --git a/docs/releases/v4.5.3.rst b/docs/releases/v4.5.3.rst
new file mode 100644
index 00000000..b1102459
--- /dev/null
+++ b/docs/releases/v4.5.3.rst
@@ -0,0 +1,49 @@
+What's new in Tornado 4.5.2
+===========================
+
+Aug 27, 2017
+------------
+
+`tornado.curl_httpclient`
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- Improved debug logging on Python 3.
+
+`tornado.httpserver`
+~~~~~~~~~~~~~~~~~~~~
+
+- ``Content-Length`` and ``Transfer-Encoding`` headers are no longer
+  sent with 1xx or 204 responses (this was already true of 304
+  responses).
+- Reading chunked requests no longer leaves the connection in a broken
+  state.
+
+`tornado.iostream`
+~~~~~~~~~~~~~~~~~~
+
+- Writing a `memoryview` can no longer result in "BufferError:
+  Existing exports of data: object cannot be re-sized".
+
+`tornado.options`
+~~~~~~~~~~~~~~~~~
+
+- Duplicate option names are now detected properly whether they use
+  hyphens or underscores.
+
+`tornado.testing`
+~~~~~~~~~~~~~~~~~
+
+- `.AsyncHTTPTestCase.fetch` now uses ``127.0.0.1`` instead of
+  ``localhost``, improving compatibility with systems that have
+  partially-working ipv6 stacks.
+
+`tornado.web`
+~~~~~~~~~~~~~
+
+- It is no longer allowed to send a body with 1xx or 204 responses.
+
+`tornado.websocket`
+~~~~~~~~~~~~~~~~~~~
+
+- Requests with invalid websocket headers now get a response with
+  status code 400 instead of a closed connection.
diff --git a/setup.py b/setup.py
index 66d846be..a1feea67 100644
--- a/setup.py
+++ b/setup.py
@@ -103,7 +103,7 @@ http://api.mongodb.org/python/current/installation.html#osx
 
 kwargs = {}
 
-version = "4.5.2"
+version = "4.5.3"
 
 with open('README.rst') as f:
     kwargs['long_description'] = f.read()
diff --git a/tornado/__init__.py b/tornado/__init__.py
index 3eaa57b8..fa71bf61 100644
--- a/tornado/__init__.py
+++ b/tornado/__init__.py
@@ -25,5 +25,5 @@ from __future__ import absolute_import, division, print_function
 # is zero for an official release, positive for a development branch,
 # or negative for a release candidate or beta (after the base version
 # number has been incremented)
-version = "4.5.2"
-version_info = (4, 5, 2, 0)
+version = "4.5.3"
+version_info = (4, 5, 3, 0)