From 6a3675e2257fe6cde2ceba89a7001d3993efdc7f Mon Sep 17 00:00:00 2001
From: luvs01 <luvs01@hanmail.net>
Date: Fri, 28 Aug 2026 13:22:09 +0900
Subject: [PATCH] fix(cursor): guard suspended checkpoint lookup

---
 src/adapters/cursor.ts                         |  1 +
 src/adapters/cursor/checkpoint-store.ts        |  3 +++
 src/adapters/cursor/request-builder.ts         |  5 ++++-
 tests/cursor-tool-suspended-checkpoint.test.ts | 18 +++++++++++++++++-
 4 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/adapters/cursor.ts b/src/adapters/cursor.ts
index 6761a3d194..0d24281609 100644
--- a/src/adapters/cursor.ts
+++ b/src/adapters/cursor.ts
@@ -195,6 +195,7 @@ export function createCursorAdapter(provider: OcxProviderConfig, deps: CursorAda
             coveredMessageCount,
             prefixDigest: cursorCoveredPrefixDigest(_parsed, coveredMessageCount),
             systemDigest: cursorInstructionDigest(_parsed),
+            toolSuspended: toolSuspendedCommit,
           });
           if (!checkpointRef) return;
           if (previousRef && previousRef !== checkpointRef) invalidateCursorCheckpoint(previousRef);
diff --git a/src/adapters/cursor/checkpoint-store.ts b/src/adapters/cursor/checkpoint-store.ts
index b9d78d9716..7cd98c5820 100644
--- a/src/adapters/cursor/checkpoint-store.ts
+++ b/src/adapters/cursor/checkpoint-store.ts
@@ -37,6 +37,7 @@ export interface CursorCheckpointSnapshot {
   coveredMessageCount?: number;
   prefixDigest?: string;
   systemDigest?: string;
+  toolSuspended?: boolean;
 }
 
 interface CursorCheckpointStore {
@@ -187,6 +188,7 @@ export function commitCursorCheckpoint(input: {
   coveredMessageCount?: number;
   prefixDigest?: string;
   systemDigest?: string;
+  toolSuspended?: boolean;
 }): string | undefined {
   if (!input.conversationId || !input.modelId || input.checkpointBytes.byteLength === 0) return undefined;
   if (input.checkpointBytes.byteLength > CURSOR_CHECKPOINT_MAX_TOTAL_BYTES) return undefined;
@@ -216,6 +218,7 @@ export function commitCursorCheckpoint(input: {
     ...(input.coveredMessageCount !== undefined ? { coveredMessageCount: input.coveredMessageCount } : {}),
     ...(input.prefixDigest ? { prefixDigest: input.prefixDigest } : {}),
     ...(input.systemDigest ? { systemDigest: input.systemDigest } : {}),
+    ...(input.toolSuspended ? { toolSuspended: true } : {}),
   };
   const blobIds = collectCheckpointBlobIds(input.checkpointBytes);
   if (blobIds === undefined) return undefined;
diff --git a/src/adapters/cursor/request-builder.ts b/src/adapters/cursor/request-builder.ts
index e99791134a..91aaeb1617 100644
--- a/src/adapters/cursor/request-builder.ts
+++ b/src/adapters/cursor/request-builder.ts
@@ -431,7 +431,10 @@ function resolveCursorCheckpoint(
   if (cursorCheckpointModelAffinityId(snapshot.modelId) !== cursorCheckpointModelAffinityId(request.modelId)) {
     return { reason: "model_changed" };
   }
-  if (parsed.context.messages.at(-1)?.role !== "toolResult" && cursorState?.checkpointUsable === false) {
+  if (
+    parsed.context.messages.at(-1)?.role !== "toolResult"
+    && (snapshot.toolSuspended === true || cursorState?.checkpointUsable === false)
+  ) {
     return { reason: "trailing_tool_result" };
   }
   const lineage = lineageMismatch(parsed, snapshot);
diff --git a/tests/cursor-tool-suspended-checkpoint.test.ts b/tests/cursor-tool-suspended-checkpoint.test.ts
index 6461d20a48..7b4147f1ae 100644
--- a/tests/cursor-tool-suspended-checkpoint.test.ts
+++ b/tests/cursor-tool-suspended-checkpoint.test.ts
@@ -1,6 +1,7 @@
 import { describe, expect, test } from "bun:test";
 import { createCursorAdapter as createCursorAdapterProduction } from "../src/adapters/cursor";
 import { clearCursorCheckpointsForTests, getCursorCheckpoint } from "../src/adapters/cursor/checkpoint-store";
+import { createCursorRequest } from "../src/adapters/cursor/request-builder";
 import { create, toBinary } from "@bufbuild/protobuf";
 import { ConversationStateStructureSchema } from "../src/adapters/cursor/gen/agent_pb";
 import type { AdapterEvent, OcxParsedRequest, OcxProviderConfig } from "../src/types";
@@ -55,7 +56,22 @@ describe("tool-suspended checkpoint commit (devlog 260826 050)", () => {
     if (done?.type !== "done") throw new Error("expected done");
     expect(done.providerState?.cursor?.checkpointRef).toBeDefined();
     expect(done.providerState?.cursor?.checkpointUsable).toBe(false);
-    expect(getCursorCheckpoint(done.providerState?.cursor?.checkpointRef)).toBeDefined();
+    expect(getCursorCheckpoint(done.providerState?.cursor?.checkpointRef)?.toolSuspended).toBe(true);
+
+    const retry = createCursorRequest(body("cursor/grok-4.6"));
+    expect(retry.continuationMode).toBe("full-replay");
+    expect(retry.checkpointInvalidationReason).toBe("trailing_tool_result");
+
+    const continuation = body("cursor/grok-4.6");
+    continuation.context.messages.push({
+      role: "toolResult",
+      toolCallId: "call_x",
+      content: "sunny",
+      timestamp: 2,
+    });
+    const resumed = createCursorRequest(continuation);
+    expect(resumed.continuationMode).toBe("checkpoint");
+    expect(resumed.checkpointBytes).toEqual(checkpointBytes);
     clearCursorCheckpointsForTests();
   });