mcp: treat empty/whitespace wing or room as no filter in tool_search

Port of upstream 9947ad0 (PR MemPalace#1097) — LLM agents tend to fill optional
parameters with "" rather than omitting them. Without this normalization,
wing="   " (whitespace-only) is truthy in searcher.py and gets passed
as a literal filter, scoping the search to a non-existent empty wing
and returning zero results.

Adapted: upstream centralizes through a _sanitize_optional_name helper
that we don't have. Inlined the strip-and-empty-as-None at the entry
point of tool_search instead, which is the only call site with this
pattern in our fork (tool_list_rooms uses `if wing:` already-falsy on
"", and tool_find_tunnels accepts no LLM-driven optional filters).

Upstream: MemPalace@9947ad0

Co-authored-by: Kunal Garhewal <kunalgarhewal13@gmail.com>
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: 3 people

mempalace/mcp_server.py

@@ -159,6 +159,13 @@ def tool_get_taxonomy():
 
 
 def tool_search(query: str, limit: int = 5, wing: str = None, room: str = None):
+    # LLM agents tend to fill every optional parameter with "" rather than
+    # omitting it. Treat empty/whitespace-only wing/room as no filter so the
+    # search isn't silently scoped to a non-existent empty wing/room.
+    if isinstance(wing, str) and not wing.strip():
+        wing = None
+    if isinstance(room, str) and not room.strip():
+        room = None
     return search_memories(
         query,
         palace_path=_config.palace_path,

tests/test_mcp_server.py

@@ -138,6 +138,32 @@ def fake_handler(**kwargs):
     assert calls == [{}]
 
 
+# ── tool_search: empty/whitespace wing/room treated as no filter (upstream #1097)
+
+
+def test_tool_search_empty_wing_room_means_no_filter(monkeypatch):
+    """LLMs often fill optional params with "" instead of omitting them.
+
+    Empty or whitespace-only wing/room must be normalized to None before
+    reaching search_memories — otherwise the search gets silently scoped
+    to a non-existent empty filter and returns 0 results.
+    """
+    captured = {}
+
+    def fake_search_memories(query, palace_path=None, wing=None, room=None, n_results=5):
+        captured["wing"] = wing
+        captured["room"] = room
+        return {"results": []}
+
+    monkeypatch.setattr(mcp_server, "search_memories", fake_search_memories)
+
+    mcp_server.tool_search("hello", wing="", room="   ")
+    assert captured == {"wing": None, "room": None}
+
+    mcp_server.tool_search("hello", wing="wing_code", room="")
+    assert captured == {"wing": "wing_code", "room": None}
+
+
 def test_tools_call_unknown_tool_returns_error():
     """Unknown tool name yields a JSON-RPC error, not a crash."""
     request = {