Upgrade PyPy to test Python 3.6

.travis.yml

@@ -1,6 +1,6 @@
 language: python
 os: linux
-dist: xenial
+dist: focal
 
 before_install:
   - env
@@ -43,13 +43,13 @@ jobs:
       env: NOX_SESSION=test-3.7
     - python: 3.8
       env: NOX_SESSION=test-3.8
-    - python: 3.9-dev
+    - python: 3.9
       env: NOX_SESSION=test-3.9
     - python: nightly
       env: NOX_SESSION=test-3.10
-    - python: pypy2.7-6.0
+    - python: pypy2.7-7.3.1
       env: NOX_SESSION=test-pypy
-    - python: pypy3.5-6.0
+    - python: pypy3.6-7.3.1
       env: NOX_SESSION=test-pypy
 
     # Extras

src/urllib3/util/ssl_.py

@@ -393,7 +393,7 @@ def ssl_wrap_socket(
     try:
         if hasattr(context, "set_alpn_protocols"):
             context.set_alpn_protocols(ALPN_PROTOCOLS)
-    except NotImplementedError:
+    except NotImplementedError:  # Defensive: in CI, we always have set_alpn_protocols
         pass
 
     # If we detect server_hostname is an IP address then the SNI

test/contrib/test_socks.py

@@ -1,8 +1,12 @@
+from __future__ import absolute_import
+
 import socket
 import threading
+from socket import getaddrinfo as real_getaddrinfo
 from test import SHORT_TIMEOUT
 
 import pytest
+import socks as py_socks
 
 from dummyserver.server import DEFAULT_CA, DEFAULT_CERTS
 from dummyserver.testcase import IPV4SocketDummyServerTestCase
@@ -87,6 +91,26 @@ def _address_from_socket(sock):
         raise RuntimeError("Unexpected addr type: %r" % addr_type)
 
 
+def _set_up_fake_getaddrinfo(monkeypatch):
+    # Work around https://github.com/urllib3/urllib3/pull/2034
+    # Nothing prevents localhost to point to two different IPs. For example, in the
+    # Ubuntu set up by GitHub Actions, localhost points both to 127.0.0.1 and ::1.
+    #
+    # In case of failure, PySocks will try the same request on both IPs, but our
+    # handle_socks[45]_negotiation functions don't handle retries, which leads either to
+    # a deadlock or a timeout in case of a failure on the first address.
+    #
+    # However, some tests need to exercise failure. We don't want retries there, but
+    # can't affect PySocks retries via its API. Instead, we monkeypatch PySocks so that
+    # it only sees a single address, which effectively disables retries.
+    def fake_getaddrinfo(addr, port, family, socket_type):
+        gai_list = real_getaddrinfo(addr, port, family, socket_type)
+        gai_list = [gai for gai in gai_list if gai[0] == socket.AF_INET]
+        return gai_list[:1]
+
+    monkeypatch.setattr(py_socks.socket, "getaddrinfo", fake_getaddrinfo)
+
+
 def handle_socks5_negotiation(sock, negotiate, username=None, password=None):
     """
     Handle the SOCKS5 handshake.
@@ -334,7 +358,8 @@ def request_handler(listener):
             with pytest.raises(NewConnectionError):
                 pm.request("GET", "http://example.com", retries=False)
 
-    def test_proxy_rejection(self):
+    def test_proxy_rejection(self, monkeypatch):
+        _set_up_fake_getaddrinfo(monkeypatch)
         evt = threading.Event()
 
         def request_handler(listener):
@@ -429,7 +454,9 @@ def request_handler(listener):
             assert response.data == b""
             assert response.headers["Server"] == "SocksTestServer"
 
-    def test_socks_with_invalid_password(self):
+    def test_socks_with_invalid_password(self, monkeypatch):
+        _set_up_fake_getaddrinfo(monkeypatch)
+
         def request_handler(listener):
             sock = listener.accept()[0]
 
@@ -592,7 +619,8 @@ def request_handler(listener):
             response = pm.request("GET", "http://example.com")
             assert response.status == 200
 
-    def test_proxy_rejection(self):
+    def test_proxy_rejection(self, monkeypatch):
+        _set_up_fake_getaddrinfo(monkeypatch)
         evt = threading.Event()
 
         def request_handler(listener):