Requests：让 redirect 处理无副作用的重构

1diff --git a/requests/sessions.py b/requests/sessions.py2index 425db22c..7bf3ea23 1006443--- a/requests/sessions.py4+++ b/requests/sessions.py-@@ -88,6 +88,8 @@ class SessionRedirectMixin(object):6         i = 07 8         while resp.is_redirect:9+            # Always derive each hop from the caller's original request so10+            # redirect handling stays side-effect free and reproducible.11             prepared_request = req.copy()12 13             resp.content  # Consume socket so it can be released-@@ -152,11 +154,6 @@ class SessionRedirectMixin(object):15 16             extract_cookies_to_jar(self.cookies, prepared_request, resp.raw)17 18-            # Persist the per-hop request so the next hop starts from the19-            # request we actually sent (method/body may differ from the20-            # caller's original request after e.g. a 303).21-            req = prepared_request22-23             i += 124             yield resp25diff --git a/test_requests.py b/test_requests.py26index 15406a25..8c93f421 10064427--- a/test_requests.py28+++ b/test_requests.py-@@ -221,6 +221,16 @@ class RequestsTestCase(unittest.TestCase):30         assert resp.status_code == 20031 32+    def test_resolve_redirects_is_side_effect_free(self):33+        req = requests.Request('POST', httpbin('redirect-to'),34+                               params={'url': httpbin('get'), 'status_code': 303},35+                               data={'k': 'v'}).prepare()36+        s = requests.Session()37+        resp = s.send(req, allow_redirects=True)38+        # The caller's request object is left untouched by redirect handling.39+        assert req.method == 'POST'40+        assert resp.status_code == 20041+42     def test_HTTP_302_ALLOW_REDIRECT_GET(self):43         r = requests.get(httpbin('redirect', '1'))44         assert r.status_code == 20045