Remove more Python 2.6 code (urllib3#1430)

dev-requirements.txt

@@ -8,4 +8,6 @@ PySocks==1.6.8
 pkginfo==1.4.2
 pytest-timeout==1.3.1
 pytest==3.6.4
-gcp-devrel-py-tools==0.0.15
+# https://github.com/GoogleCloudPlatform/python-repo-tools/issues/23
+pylint<2.0;python_version<="2.7"
+gcp-devrel-py-tools==0.0.15

src/urllib3/connection.py

@@ -171,10 +171,7 @@ def _new_conn(self):
 
     def _prepare_conn(self, conn):
         self.sock = conn
-        # the _tunnel_host attribute was added in python 2.6.3 (via
-        # http://hg.python.org/cpython/rev/0f57b30a152f) so pythons 2.6(0-2) do
-        # not have them.
-        if getattr(self, '_tunnel_host', None):
+        if self._tunnel_host:
             # TODO: Fix tunnel so it doesn't depend on self.sock state.
             self._tunnel()
             # Mark this connection as not reusable
@@ -302,12 +299,9 @@ def set_cert(self, key_file=None, cert_file=None,
     def connect(self):
         # Add certificate verification
         conn = self._new_conn()
-
         hostname = self.host
-        if getattr(self, '_tunnel_host', None):
-            # _tunnel_host was added in Python 2.6.3
-            # (See: http://hg.python.org/cpython/rev/0f57b30a152f)
 
+        if self._tunnel_host:
             self.sock = conn
             # Calls self._set_hostport(), so self.host is
             # self._tunnel_host below.

src/urllib3/connectionpool.py

@@ -313,7 +313,7 @@ def _raise_timeout(self, err, url, timeout_value):
         # Catch possible read timeouts thrown as SSL errors. If not the
         # case, rethrow the original. We need to do this because of:
         # http://bugs.python.org/issue10272
-        if 'timed out' in str(err) or 'did not complete (read)' in str(err):  # Python 2.6
+        if 'timed out' in str(err) or 'did not complete (read)' in str(err):  # Python < 2.7.4
             raise ReadTimeoutError(self, url, "Read timed out. (read timeout=%s)" % timeout_value)
 
     def _make_request(self, conn, method, url, timeout=_Default, chunked=False,

src/urllib3/packages/ssl_match_hostname/_implementation.py

@@ -9,8 +9,7 @@
 # ipaddress has been backported to 2.6+ in pypi.  If it is installed on the
 # system, use it to handle IPAddress ServerAltnames (this was added in
 # python-3.5) otherwise only do DNS matching.  This allows
-# backports.ssl_match_hostname to continue to be used all the way back to
-# python-2.4.
+# backports.ssl_match_hostname to continue to be used in Python 2.7.
 try:
     import ipaddress
 except ImportError:

test/test_response.py

@@ -291,23 +291,6 @@ def test_io_bufferedreader(self):
         while not br.closed:
             br.read(5)
 
-    def test_io_readinto(self):
-        # This test is necessary because in py2.6, `readinto` doesn't get called
-        # in `test_io_bufferedreader` like it does for all the other python
-        # versions.  Probably this is because the `io` module in py2.6 is an
-        # old version that has a different underlying implementation.
-
-        fp = BytesIO(b'foo')
-        resp = HTTPResponse(fp, preload_content=False)
-
-        barr = bytearray(3)
-        assert resp.readinto(barr) == 3
-        assert b'foo' == barr
-
-        # The reader should already be empty, so this should read nothing.
-        assert resp.readinto(barr) == 0
-        assert b'foo' == barr
-
     def test_streaming(self):
         fp = BytesIO(b'foo')
         resp = HTTPResponse(fp, preload_content=False)

test/with_dummyserver/test_https.py

@@ -38,6 +38,7 @@
     SystemTimeWarning,
     InsecurePlatformWarning,
     MaxRetryError,
+    ProtocolError,
 )
 from urllib3.packages import six
 from urllib3.util.timeout import Timeout
@@ -101,7 +102,12 @@ def test_client_no_intermediate(self):
                     'invalid certificate chain' in str(e) or
                     'unknown Cert Authority' in str(e) or
                     # https://github.com/urllib3/urllib3/issues/1422
-                    'connection closed via error' in str(e)):
+                    'connection closed via error' in str(e) or
+                    'WSAECONNRESET' in str(e)):
+                raise
+        except ProtocolError as e:
+            # https://github.com/urllib3/urllib3/issues/1422
+            if not ('An existing connection was forcibly closed by the remote host' in str(e)):
                 raise
 
     def test_verified(self):

test/with_dummyserver/test_socketlevel.py

@@ -639,13 +639,6 @@ def socket_handler(listener):
     def test_closing_response_actually_closes_connection(self):
         done_closing = Event()
         complete = Event()
-        # The insane use of this variable here is to get around the fact that
-        # Python 2.6 does not support returning a value from Event.wait(). This
-        # means we can't tell if an event timed out, so we can't use the timing
-        # out of the 'complete' event to determine the success or failure of
-        # the test. Python 2 also doesn't have the nonlocal statement, so we
-        # can't write directly to this variable, only mutate it. Hence: list.
-        successful = []
 
         def socket_handler(listener):
             sock = listener.accept()[0]
@@ -667,7 +660,6 @@ def socket_handler(listener):
             sock.settimeout(1)
             new_data = sock.recv(65536)
             self.assertFalse(new_data)
-            successful.append(True)
             sock.close()
             complete.set()
 
@@ -680,7 +672,7 @@ def socket_handler(listener):
         response.close()
 
         done_closing.set()  # wait until the socket in our pool gets closed
-        complete.wait(timeout=1)
+        successful = complete.wait(timeout=1)
         if not successful:
             self.fail("Timed out waiting for connection close")