Use tz-aware functions in Retry.parse_retry_after()

dev-requirements.txt

@@ -7,6 +7,7 @@ PySocks==1.7.1
 win-inet-pton==1.1.0
 pytest==4.6.9
 pytest-timeout==1.3.4
+pytest-freezegun==0.3.0.post1
 flaky==3.6.1
 trustme==0.5.3
 cryptography==2.8

src/urllib3/util/retry.py

@@ -266,10 +266,10 @@ def parse_retry_after(self, retry_after):
         if re.match(r"^\s*[0-9]+\s*$", retry_after):
             seconds = int(retry_after)
         else:
-            retry_date_tuple = email.utils.parsedate(retry_after)
+            retry_date_tuple = email.utils.parsedate_tz(retry_after)
             if retry_date_tuple is None:
                 raise InvalidHeader("Invalid Retry-After header: %s" % retry_after)
-            retry_date = time.mktime(retry_date_tuple)
+            retry_date = email.utils.mktime_tz(retry_date_tuple)
             seconds = retry_date - time.time()
 
         if seconds < 0:

test/test_retry.py

@@ -1,7 +1,5 @@
-import datetime
 import mock
 import pytest
-import time
 
 from urllib3.response import HTTPResponse
 from urllib3.packages import six
@@ -313,6 +311,7 @@ def test_respect_retry_after_header_propagated(self, respect_retry_after_header)
         new_retry = retry.new()
         assert new_retry.respect_retry_after_header == respect_retry_after_header
 
+    @pytest.mark.freeze_time("2019-06-03 11:00:00", tz_offset=0)
     @pytest.mark.parametrize(
         "retry_after_header,respect_retry_after_header,sleep_duration",
         [
@@ -326,24 +325,19 @@ def test_respect_retry_after_header_propagated(self, respect_retry_after_header)
             ("Mon, 3 Jun 2019 11:00:00 UTC", True, None),
             # Won't sleep due to current time reached + not respecting header
             ("Mon, 3 Jun 2019 11:00:00 UTC", False, None),
+            # Handle all the formats in RFC 7231 Section 7.1.1.1
+            ("Mon, 03 Jun 2019 11:30:12 GMT", True, 1812),
+            ("Monday, 03-Jun-19 11:30:12 GMT", True, 1812),
+            # Assume that datetimes without a timezone are in UTC per RFC 7231
+            ("Mon Jun  3 11:30:12 2019", True, 1812),
         ],
     )
     def test_respect_retry_after_header_sleep(
         self, retry_after_header, respect_retry_after_header, sleep_duration
     ):
         retry = Retry(respect_retry_after_header=respect_retry_after_header)
 
-        # Date header syntax can specify an absolute date; compare this to the
-        # time in the parametrized inputs above.
-        current_time = mock.MagicMock(
-            return_value=time.mktime(
-                datetime.datetime(year=2019, month=6, day=3, hour=11).timetuple()
-            )
-        )
-
-        with mock.patch("time.sleep") as sleep_mock, mock.patch(
-            "time.time", current_time
-        ):
+        with mock.patch("time.sleep") as sleep_mock:
             # for the default behavior, it must be in RETRY_AFTER_STATUS_CODES
             response = HTTPResponse(
                 status=503, headers={"Retry-After": retry_after_header}