refactor(acp): events _upgrade_queue single key; edit_approval uses Path.is_relative_to; session toolset expansion via dict.fromkeys; fork_session early return

acp_adapter/edit_approval.py

@@ -115,8 +115,8 @@ def _proposal_for_patch_v4a(arguments: dict[str, Any]) -> EditProposal:
     if not paths:
         raise ValueError("no file paths found in V4A patch")
     single = len(paths) == 1
-    # ACP only supports a single diff payload: surface the exact V4A patch as
-    # new_text so patch-mode calls are permissioned and denied patches cannot mutate.
+    # ACP only supports a single diff payload: surface the exact V4A patch as new_text so
+    # patch-mode calls are permissioned and denied patches cannot mutate.
     return EditProposal(
         "patch", paths[0] if single else ", ".join(paths),
         _read_text_if_exists(paths[0]) if single else None, patch_body, dict(arguments),
@@ -143,14 +143,6 @@ def _is_sensitive_auto_approve_path(path: str) -> bool:
     return bool(lowered & {".git", ".ssh"}) or Path(path).name.lower() in SENSITIVE_AUTO_APPROVE_NAMES
 
 
-def _is_under(path: Path, root: Path) -> bool:
-    try:
-        path.relative_to(root)
-        return True
-    except ValueError:
-        return False
-
-
 def should_auto_approve_edit(proposal: EditProposal, policy: str, cwd: str | None = None) -> bool:
     """Return whether an ACP edit proposal may bypass the prompt for this session.
 
@@ -165,10 +157,10 @@ def should_auto_approve_edit(proposal: EditProposal, policy: str, cwd: str | Non
     if policy == AUTO_APPROVE_WORKSPACE:
         # tempfile.gettempdir() is the real temp root on every platform
         # (``/private/tmp`` on macOS since resolve() follows the symlink).
-        if _is_under(path, Path(tempfile.gettempdir()).resolve(strict=False)):
+        if path.is_relative_to(Path(tempfile.gettempdir()).resolve(strict=False)):
             return True
         if cwd:
-            return _is_under(path, Path(cwd).expanduser().resolve(strict=False))
+            return path.is_relative_to(Path(cwd).expanduser().resolve(strict=False))
     return False
 
 

acp_adapter/events.py

@@ -65,12 +65,11 @@ def _send_update(conn: acp.Client, session_id: str, loop: asyncio.AbstractEventL
         logger.debug("Failed to send ACP update", exc_info=True)
 
 
-def _upgrade_queue(tool_call_ids: Dict[str, Deque[str]], key: Any, store_key: Any) -> Deque[str] | None:
+def _upgrade_queue(tool_call_ids: Dict[str, Deque[str]], name: str) -> Deque[str] | None:
     """Fetch the per-tool FIFO of pending call IDs, upgrading a legacy bare-string entry in place."""
-    queue = tool_call_ids.get(key)
+    queue = tool_call_ids.get(name)
     if isinstance(queue, str):
-        queue = deque([queue])
-        tool_call_ids[store_key] = queue
+        queue = tool_call_ids[name] = deque([queue])
     return queue
 
 
@@ -102,7 +101,7 @@ def make_tool_progress_cb(
             args = {}
 
         tc_id = make_tool_call_id()
-        queue = _upgrade_queue(tool_call_ids, name, name)
+        queue = _upgrade_queue(tool_call_ids, name)
         if queue is None:
             queue = tool_call_ids[name] = deque()
         queue.append(tc_id)
@@ -174,8 +173,10 @@ def make_step_cb(
             elif isinstance(tool_info, str):
                 tool_name = tool_info
 
-            queue = _upgrade_queue(tool_call_ids, tool_name or "", tool_name)
-            if not tool_name or not queue:
+            if not tool_name:
+                continue
+            queue = _upgrade_queue(tool_call_ids, tool_name)
+            if not queue:
                 continue
             tc_id = queue.popleft()
             meta = tool_call_meta.pop(tc_id, {})

acp_adapter/server.py

@@ -1299,16 +1299,14 @@ class HermesACPAgent(acp.Agent):
         self, cwd: str, session_id: str, mcp_servers: list | None = None, **kwargs: Any
     ) -> ForkSessionResponse:
         state = self.session_manager.fork_session(session_id, cwd=cwd)
-        new_id = state.session_id if state else ""
-        if state is not None:
-            await self._register_session_mcp_servers(state, mcp_servers)
-        logger.info("Forked session %s -> %s", session_id, new_id)
-        if new_id:
-            self._schedule_available_commands_update(new_id)
+        if state is None:
+            logger.info("Forked session %s -> %s", session_id, "")
+            return ForkSessionResponse(session_id="")
+        await self._register_session_mcp_servers(state, mcp_servers)
+        logger.info("Forked session %s -> %s", session_id, state.session_id)
+        self._schedule_available_commands_update(state.session_id)
         return ForkSessionResponse(
-            session_id=new_id,
-            models=self._build_model_state(state) if state is not None else None,
-            modes=self._session_modes(state) if state is not None else None,
+            session_id=state.session_id, models=self._build_model_state(state), modes=self._session_modes(state)
         )
 
     async def list_sessions(

acp_adapter/session.py

@@ -104,15 +104,9 @@ def _register_task_cwd(task_id: str, cwd: str) -> None:
 def _expand_acp_enabled_toolsets(toolsets: List[str] | None = None,
                                  mcp_server_names: List[str] | None = None) -> List[str]:
     """Return ACP toolsets plus explicit MCP server toolsets for this session."""
-    expanded: List[str] = []
-    for name in list(toolsets or ["hermes-acp"]):
-        if name and name not in expanded:
-            expanded.append(name)
-    for server_name in list(mcp_server_names or []):
-        toolset_name = f"mcp-{server_name}"
-        if server_name and toolset_name not in expanded:
-            expanded.append(toolset_name)
-    return expanded
+    names = [n for n in (toolsets or ["hermes-acp"]) if n]
+    names += [f"mcp-{s}" for s in (mcp_server_names or []) if s]
+    return list(dict.fromkeys(names))
 
 
 def _parse_model_config(mc: Any) -> dict:
@@ -223,7 +217,7 @@ class SessionManager:
             seen_ids = set(self._sessions.keys())
             results = []
             for s in self._sessions.values():
-                if len(s.history) <= 0 or not _matches(s.cwd):
+                if not s.history or not _matches(s.cwd):
                     continue
                 persisted = persisted_rows.get(s.session_id, {})
                 results.append(_session_info(
@@ -387,7 +381,7 @@ class SessionManager:
         default_model, config_provider = "", None
         if isinstance(model_cfg, dict):
             default_model, config_provider = str(model_cfg.get("default") or ""), model_cfg.get("provider")
-        elif isinstance(model_cfg, str) and model_cfg.strip():
+        elif isinstance(model_cfg, str):
             default_model = model_cfg.strip()
 
         configured_mcp_servers = [