From 29f4f7db1f623a2c2adab3006a21f4dcc59be791 Mon Sep 17 00:00:00 2001
From: Yegor Roganov <yegor.rog@gmail.com>
Date: Thu, 13 Jul 2017 22:47:42 +0300
Subject: [PATCH] Fix bug in CookieJar when a cookie would be expired by
 mistake

Fixes #2084
---
 CONTRIBUTORS.txt        |  1 +
 aiohttp/cookiejar.py    |  2 +-
 changes/2084.bugfix     |  1 +
 tests/test_cookiejar.py | 19 +++++++++++++++++++
 4 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 changes/2084.bugfix

diff --git a/CONTRIBUTORS.txt b/CONTRIBUTORS.txt
index c20e0cb217f..c6c44075700 100644
--- a/CONTRIBUTORS.txt
+++ b/CONTRIBUTORS.txt
@@ -178,6 +178,7 @@ Will McGugan
 Willem de Groot
 Wilson Ong
 Yannick Koechlin
+Yegor Roganov
 Young-Ho Cha
 Yuriy Shatrov
 Yury Selivanov
diff --git a/aiohttp/cookiejar.py b/aiohttp/cookiejar.py
index 968b084716b..37e802cb15d 100644
--- a/aiohttp/cookiejar.py
+++ b/aiohttp/cookiejar.py
@@ -74,7 +74,7 @@ def _do_expiration(self):
         cookies = self._cookies
         expirations = self._expirations
         for (domain, name), when in expirations.items():
-            if when < now:
+            if when <= now:
                 cookies[domain].pop(name, None)
                 to_del.append((domain, name))
                 self._host_only_cookies.discard((domain, name))
diff --git a/changes/2084.bugfix b/changes/2084.bugfix
new file mode 100644
index 00000000000..f3c61ba1237
--- /dev/null
+++ b/changes/2084.bugfix
@@ -0,0 +1 @@
+Fix issue with CookieJar incorrectly expiring cookies in some edge cases.
diff --git a/tests/test_cookiejar.py b/tests/test_cookiejar.py
index eef27ddfe8c..28475f26dcc 100644
--- a/tests/test_cookiejar.py
+++ b/tests/test_cookiejar.py
@@ -1,5 +1,6 @@
 import asyncio
 import datetime
+import itertools
 import os
 import tempfile
 import unittest
@@ -577,3 +578,21 @@ def test_invalid_values(self):
 
         cookie = cookies_sent["invalid-expires-cookie"]
         self.assertEqual(cookie["expires"], "")
+
+    def test_cookie_not_expired_when_added_after_removal(self):
+        """Test case for https://github.com/aio-libs/aiohttp/issues/2084"""
+        timestamps = [533588.993, 533588.993, 533588.993,
+                      533588.993, 533589.093, 533589.093]
+
+        loop = mock.Mock()
+        loop.time.side_effect = itertools.chain(
+            timestamps, itertools.cycle([timestamps[-1]]))
+
+        jar = CookieJar(unsafe=True, loop=loop)
+        # Remove `foo` cookie.
+        jar.update_cookies(SimpleCookie('foo=""; Max-Age=0'))
+        # Set `foo` cookie to `bar`.
+        jar.update_cookies(SimpleCookie('foo="bar"'))
+
+        # Assert that there is a cookie.
+        assert len(jar) == 1