Mittwald-/Login-API: Weiterleitungen folgen (wie requests); nicht gefolgte 3xx-Antwort ist ein Fehler statt leerer Erfolg

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tests/test_core_contract.py

@@ -492,3 +492,22 @@ def test_cortecs_key_from_admin_env_counts_as_set_and_reaches_the_container(clie
         assert deploy.build_env(db, t, reveal=True)["CORTECS_API_KEY"] == "ck-aus-env"
         assert "ck-aus-env" not in str(deploy.build_env(db, t, reveal=False))
         assert "aus Admin-Env" in deploy.build_env(db, t, reveal=False)["CORTECS_API_KEY"]
+
+
+def test_http_clients_follow_redirects_and_3xx_is_never_success(monkeypatch):
+    import httpx
+    from app.services import mittwald as mwmod, onyva_login
+    from app.services.mittwald import DeployError, Mittwald
+    seen = []
+
+    class R:
+        status_code, content, text = 200, b"[]", "[]"
+        def json(self): return []
+
+    monkeypatch.setattr(httpx, "request", lambda *a, **k: (seen.append(k), R())[1])
+    Mittwald._real_http("GET", "https://x/v2/stacks/", {}, None)
+    onyva_login.OnyvaLogin._real("GET", "https://x/api/v1/apps", {}, None)
+    assert all(k.get("follow_redirects") is True for k in seen) and len(seen) == 2
+    # Eine nicht gefolgte 308-Weiterleitung (leerer Body) ist ein Fehler, kein „null“
+    with pytest.raises(DeployError, match="308"):
+        Mittwald("t", "https://api.test/v2", False, lambda m: None, lambda *a: (308, None, "")).api("GET", "/projects/p/stacks/", write=False)