From ac16dc5e6453ac7704e4edc21ced019be638b288 Mon Sep 17 00:00:00 2001
From: 134 <a134@134deMacBook-Pro.local>
Date: Tue, 23 Jun 2026 13:35:54 +0800
Subject: [PATCH] fix: reject rapid stale canvas autosaves

---
 lib/canvas/canvas-save-conflict.ts       | 2 +-
 tests/routes/canvas-chat-helpers.test.ts | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/canvas/canvas-save-conflict.ts b/lib/canvas/canvas-save-conflict.ts
index 1a7364243..0bb8c94ed 100644
--- a/lib/canvas/canvas-save-conflict.ts
+++ b/lib/canvas/canvas-save-conflict.ts
@@ -16,7 +16,7 @@ export function isStaleCanvasSaveBaseRevision(params: {
     params.baseCanvasUpdatedAt || params.baseCanvasRevision
   );
   if (!baseDate) return false;
-  return baseDate.getTime() + 1000 < params.currentUpdatedAt.getTime();
+  return baseDate.getTime() < params.currentUpdatedAt.getTime();
 }
 
 export function buildStaleCanvasSaveConflictPayload(currentUpdatedAt: Date) {
diff --git a/tests/routes/canvas-chat-helpers.test.ts b/tests/routes/canvas-chat-helpers.test.ts
index 28fae44c4..ae8185464 100644
--- a/tests/routes/canvas-chat-helpers.test.ts
+++ b/tests/routes/canvas-chat-helpers.test.ts
@@ -145,6 +145,12 @@ test.describe("canvas chat pure helpers", () => {
         baseCanvasUpdatedAt: "2026-06-22T00:00:05.000Z",
         currentUpdatedAt,
       })
+    ).toBe(true);
+    expect(
+      isStaleCanvasSaveBaseRevision({
+        baseCanvasUpdatedAt: "2026-06-22T00:00:05.500Z",
+        currentUpdatedAt,
+      })
     ).toBe(false);
     expect(
       isStaleCanvasSaveBaseRevision({