legacy repository: support redirected url

poetry/repositories/legacy_repository.py

@@ -387,8 +387,17 @@ class LegacyRepository(PyPiRepository):
 
         if response.status_code in (401, 403):
             self._log(
-                "Authorization error accessing {url}".format(url=url), level="warn"
+                "Authorization error accessing {url}".format(url=response.url),
+                level="warn",
             )
             return
 
-        return Page(url, response.content, response.headers)
+        if response.url != url:
+            self._log(
+                "Response URL {response_url} differs from request URL {url}".format(
+                    response_url=response.url, url=url
+                ),
+                level="debug",
+            )
+
+        return Page(response.url, response.content, response.headers)

tests/repositories/test_legacy_repository.py

@@ -3,6 +3,7 @@ import shutil
 from pathlib import Path
 
 import pytest
+import requests
 
 from poetry.core.packages import Dependency
 from poetry.factory import Factory
@@ -322,3 +323,17 @@ def test_get_4xx_and_5xx_raises(http):
     for endpoint in endpoints:
         with pytest.raises(RepositoryError):
             repo._get(endpoint)
+
+
+def test_get_redirected_response_url(http, monkeypatch):
+    repo = MockHttpRepository({"/foo": 200}, http)
+    redirect_url = "http://legacy.redirect.bar"
+
+    def get_mock(url):
+        response = requests.Response()
+        response.status_code = 200
+        response.url = redirect_url + "/foo"
+        return response
+
+    monkeypatch.setattr(repo.session, "get", get_mock)
+    assert repo._get("/foo")._url == "http://legacy.redirect.bar/foo/"