The write-ahead log gained its own module in v3.5.0 but sat at 82% coverage;
the uncovered lines were exactly the failure/guard branches that uphold its
contracts: the cache-hit early return, the restricted-FS chmod/mkdir swallow
paths, and the promise that a WAL write failure is logged and never crashes
the calling tool. Add five tests covering those branches plus the non-string
redaction marker, bringing mempalace/wal.py to 100% and locking the
crash-safety guarantees against regression. Test-only; no production change.
Five fixes from the Copilot review of the merged daemon PR:
1. Privacy: the queue DB's SQLite WAL/SHM sidecars hold un-checkpointed
verbatim payloads but were created with the caller's umask. Set the
owner-only umask in run_server BEFORE DaemonRuntime builds the QueueStore
(not only once the HTTP server starts), and harden any existing sidecars in
QueueStore._init_db as defense-in-depth.
2. DoS guard: reject a negative Content-Length in the request reader.
rfile.read(-1) would block until the client disconnects and bypass the
MAX_BODY_BYTES cap.
3. Side effects: extract _wal_log (+ _ensure_wal, _WAL_FILE, _WAL_REDACT_KEYS)
into a new side-effect-free mempalace/wal.py. The CLI sync path and the
daemon service layer obtained _wal_log via `from .mcp_server import _wal_log`,
which runs mcp_server's import-time stdio protection (os.dup2(2, 1);
sys.stdout = sys.stderr) in a non-MCP process and misroutes operator output.
mcp_server/cli/service now import from mempalace.wal.
4. Correctness: run_mcp_tool treated any dict as success. Write tools that
return a bare {"error": ...} (e.g. tool_create_tunnel/tool_delete_tunnel
validation) were recorded as succeeded; now the "error" key infers failure.
5. Hook budget: get_client_if_running()/health() take an explicit timeout, and
the hook "is the daemon up?" precheck uses a short HOOK_PROBE_TIMEOUT (0.5s)
so a wedged daemon can't stall the hook for the default 5s.
Adds tests/test_wal.py (import isolation + redaction) and daemon tests for the
umask ordering, negative Content-Length, run_mcp_tool error inference, and the
short probe timeout.
Arnold Wender
Igor Lins e Silva