Fix redirects with changing cookie values

CHANGES/3576.bugfix

@@ -0,0 +1 @@
+Fix an issue where cookies would sometimes not be set during a redirect.

CONTRIBUTORS.txt

@@ -26,6 +26,7 @@ Alexey Popravka
 Alexey Stepanov
 Amin Etesamian
 Amy Boyle
+Anders Melchiorsen
 Andrei Ursulenko
 Andrej Antonov
 Andrew Leech

aiohttp/client.py

@@ -423,16 +423,14 @@ async def _request(
                                          "with AUTH argument or credentials "
                                          "encoded in URL")
 
-                    session_cookies = self._cookie_jar.filter_cookies(url)
+                    all_cookies = self._cookie_jar.filter_cookies(url)
 
                     if cookies is not None:
                         tmp_cookie_jar = CookieJar()
                         tmp_cookie_jar.update_cookies(cookies)
                         req_cookies = tmp_cookie_jar.filter_cookies(url)
                         if req_cookies:
-                            session_cookies.load(req_cookies)
-
-                    cookies = session_cookies
+                            all_cookies.load(req_cookies)
 
                     if proxy is not None:
                         proxy = URL(proxy)
@@ -446,7 +444,7 @@ async def _request(
                     req = self._request_class(
                         method, url, params=params, headers=headers,
                         skip_auto_headers=skip_headers, data=data,
-                        cookies=cookies, auth=auth, version=version,
+                        cookies=all_cookies, auth=auth, version=version,
                         compress=compress, chunked=chunked,
                         expect100=expect100, loop=self._loop,
                         response_class=self._response_class,

tests/test_client_functional.py

@@ -1884,6 +1884,34 @@ async def handler(request):
     resp.close()
 
 
+async def test_cookies_redirect(aiohttp_client) -> None:
+
+    async def redirect1(request):
+        ret = web.Response(status=301, headers={'Location': '/redirect2'})
+        ret.set_cookie('c', '1')
+        return ret
+
+    async def redirect2(request):
+        ret = web.Response(status=301, headers={'Location': '/'})
+        ret.set_cookie('c', '2')
+        return ret
+
+    async def handler(request):
+        assert request.cookies.keys() == {'c'}
+        assert request.cookies['c'] == '2'
+        return web.Response()
+
+    app = web.Application()
+    app.router.add_get('/redirect1', redirect1)
+    app.router.add_get('/redirect2', redirect2)
+    app.router.add_get('/', handler)
+
+    client = await aiohttp_client(app)
+    resp = await client.get('/redirect1')
+    assert 200 == resp.status
+    resp.close()
+
+
 async def test_cookies_on_empty_session_jar(aiohttp_client) -> None:
     async def handler(request):
         assert 'custom-cookie' in request.cookies