app/canvas/[id]/CanvasEditorLegacyPageClient.tsx

@@ -5413,7 +5413,6 @@ export default function CanvasEditorLegacyPage({
     const onVisibilityChange = () => {
       if (!canvasLeaveApprovedRef.current && document.visibilityState === "hidden" && hasUnsavedCanvasChanges()) {
         writeCanvasDraft(id, { base: savedCanvasSnapshotRef.current!.snapshot, snapshot: JSON.stringify({ canvasData: buildPersistedCanvasData() }) });
-        retrySync();
       }
     };
     const retryTimer = window.setInterval(() => {

tests/e2e/canvas-autosync.test.ts

@@ -143,6 +143,21 @@ test("only unsaved content blocks closing and beforeunload does not issue duplic
   expect(errors).toEqual([]);
 });
 
+test("pagehide and visibilitychange issue only one closing save", async ({ page }) => {
+  const { state, errors } = await setup(page);
+  state.failSave = true;
+  await moveImage(page);
+  const writes = state.writes.length;
+  await page.evaluate(() => {
+    window.dispatchEvent(new Event("pagehide"));
+    Object.defineProperty(document, "visibilityState", { value: "hidden", configurable: true });
+    document.dispatchEvent(new Event("visibilitychange"));
+  });
+  await expect.poll(() => state.writes.length).toBe(writes + 1);
+  expect(state.submissions).toHaveLength(0);
+  expect(errors).toEqual([]);
+});
+
 test("leaving with pending changes can continue editing or save before navigating", async ({ page }) => {
   const { state, errors } = await setup(page);
   await page.route(url => url.pathname === "/", route => route.fulfill({ contentType: "text/html; charset=utf-8", body: "<p>已返回首页</p>" }));