test: add local 2x2 route topology

src/archive_clients/qbittorrent.py

@@ -125,10 +125,14 @@ class QBittorrentReader:
             headers={"Content-Type": "application/x-www-form-urlencoded"},
         )
         try:
-            response = self._read(self._opener.open(call, timeout=self.timeout), 64)
+            login_response = self._opener.open(call, timeout=self.timeout)
+            login_status = getattr(login_response, "status", 200)
+            response = self._read(login_response, 64)
         except (error.URLError, OSError) as exc:
             raise QBittorrentError("qBittorrent authentication failed") from exc
-        if response.strip() != b"Ok.":
+        if response.strip() != b"Ok." and not (
+            login_status == 204 and not response.strip()
+        ):
             raise QBittorrentError("qBittorrent authentication failed")
         self._authenticated = True
 

src/archive_clients/services.py

@@ -55,7 +55,12 @@ def probe_qbittorrent(
             method="POST",
             headers={"Content-Type": "application/x-www-form-urlencoded"},
         )
-        if _read(opener.open(login, timeout=timeout)).strip() != "Ok.":
+        login_response = opener.open(login, timeout=timeout)
+        login_status = getattr(login_response, "status", 200)
+        login_body = _read(login_response).strip()
+        if login_body != "Ok." and not (
+            login_status == 204 and not login_body
+        ):
             raise PermissionError("qBittorrent authentication failed")
         version = _text_get(opener, config.endpoint, "/api/v2/app/version", timeout)
         api_version = _text_get(

src/archive_clients/syncthing.py

@@ -325,6 +325,13 @@ def _ack_name(nonce_owner: str, observer: str) -> str:
 
 def _atomic_json(path: Path, value: dict[str, Any]) -> None:
     encoded = json.dumps(value, sort_keys=True, separators=(",", ":"))
+    try:
+        if path.read_text(encoding="utf-8") == encoded:
+            return
+    except FileNotFoundError:
+        pass
+    except (OSError, UnicodeError) as exc:
+        raise RouteSetupError("route verification file is unreadable") from exc
     temporary = path.with_name(
         f".{path.name}.{os.getpid()}.{uuid.uuid4().hex}.tmp"
     )