Redirecting deep links after login

tests/test_scope_guide.py

@@ -238,4 +238,5 @@ async def test_scopes_page_forbidden_without_permission(client, seeded, make_use
 async def test_scopes_page_redirects_when_anonymous(client):
     resp = await client.get("/scopes")
     assert resp.status_code == 302
-    assert resp.headers["location"] == "/login"
+    # Deep link is preserved so the user lands back here after logging in.
+    assert resp.headers["location"] == "/login?next=%2Fscopes"