fix: don't wipe a store just because this window can't open it, and don't send a stand-in when a file's upload is held again

lib/offline/__tests__/review-fixes.test.ts

@@ -460,6 +460,19 @@ describe('a send the server couldn\'t take right now', () => {
     expect(row).toMatchObject({ status: 'waiting', copyId: 'copy-1' });
   });
 
+  it('doesn\'t hand an online send a stand-in for a file the upload held again', async () => {
+    writeEnabled(['acc']);
+    stop = startOfflineMode();
+    const { blobId } = await holdFile('acc', new File(['x'], 'x.txt', { type: 'text/plain' }), 'x.txt');
+    const client = fakeClient('https://mail.example.org', { uploadBlob: vi.fn(async () => ({ blobId: `${LOCAL_BLOB_PREFIX}stand-in`, size: 1, type: 'text/plain' })) });
+    useAuthStore.setState({ client: client as never, activeAccountId: 'acc', getClientForAccount: () => client } as never);
+    try {
+      await expect(getOutboxHooks()!.resolveHeldAttachments(client as never, [{ blobId }])).rejects.toMatchObject({ name: 'SendNotStartedError' });
+    } finally {
+      useAuthStore.setState({ getClientForAccount: useRealClient, client: null });
+    }
+  });
+
   it('doesn\'t send a stand-in for a file the upload held again', async () => {
     writeEnabled(['acc']);
     const { blobId } = await holdFile('acc', new File(['x'], 'x.txt', { type: 'text/plain' }), 'x.txt');
@@ -583,13 +596,16 @@ describe('a browser that can\'t run the store', () => {
     expect(await strandedLegacyMessages()).toBe(0);
   });
 
-  it('turns the switch off in a window that refuses the private file system', async () => {
-    writeEnabled([]);
+  it('turns the switch off in a window that refuses the private file system, and wipes nothing', async () => {
+    writeEnabled(['acc']);
     Object.defineProperty(window.navigator, 'storage', { configurable: true, value: { getDirectory: async () => { throw new DOMException('The operation is insecure.', 'SecurityError'); } } });
     try {
       stop = startOfflineMode();
       await vi.waitFor(() => expect(useOfflineStore.getState().storageBlocked).toBe(true));
       expect(offlineSupported()).toBe(false);
+      enforcePolicy();
+      await new Promise((resolve) => setTimeout(resolve, 20));
+      expect(useOfflineStore.getState().enabled).toEqual(['acc']);
     } finally {
       delete (window.navigator as { storage?: unknown }).storage;
       useOfflineStore.setState({ storageBlocked: false });

lib/offline/offline-mode.ts

@@ -39,7 +39,7 @@ import { useEmailStore } from '@/stores/email-store';
 import { usePolicyStore, whenPolicySettled } from '@/stores/policy-store';
 import { onBeforeSignOut, onFullSignOut } from '@/lib/sign-out-cleanup';
 import { generateMessageId } from '@/lib/jmap/client';
-import { setOfflineHooks, type OfflineClientRef, type OfflineHooks, type OfflineMethodCall, type OfflineResponse } from '@/lib/jmap/offline-hooks';
+import { SendNotStartedError, setOfflineHooks, type OfflineClientRef, type OfflineHooks, type OfflineMethodCall, type OfflineResponse } from '@/lib/jmap/offline-hooks';
 import type { SendEmailResult } from '@/lib/jmap/types';
 import { setOutboxHooks, type OutboxHooks } from './outbox-hooks';
 import {
@@ -99,7 +99,8 @@ function hasIndexedDb(): boolean {
 
 /** Offline mode is possible here at all: not in Lite, with what the store needs. */
 export function offlineSupported(): boolean {
-  if (IS_LITE || !hasIndexedDb() || useOfflineStore.getState().storageBlocked) return false;
+  if (IS_LITE || !hasIndexedDb()) return false;
+  if (useOfflineStore.getState().storageBlocked) return false;
   try {
     return typeof crypto !== 'undefined' && !!crypto.subtle && getStore().supported();
   } catch {
@@ -457,6 +458,8 @@ const outbox: OutboxHooks = {
       const file = await heldFile(account, attachment.blobId);
       if (!file) throw Object.assign(new Error('A file attached offline is no longer on this device'), { name: 'OfflineFileMissingError' });
       const { blobId } = await real.uploadBlob(file);
+      // The server went away just now, and offline mode held the file again.
+      if (isLocalBlobId(blobId)) throw new SendNotStartedError();
       out.push({ ...attachment, blobId });
     }
     return out;
@@ -814,7 +817,9 @@ export function enforcePolicy(): void {
   if (!loaded) return;
   for (const account of useOfflineStore.getState().enabled) {
     if (!policyDecided(account)) continue;
-    if (!offlineAllowed(account)) {
+    // What the organisation says, not whether this window can open the store:
+    // a blocked store says nothing against the data in it.
+    if (devicesForAccount(account).noOffline) {
       // Whoever is here now wasn't signed in to a dropped account.
       const someoneElses = isEvicted(account);
       clearHandoffs();

lib/store/__tests__/outbox.test.ts

@@ -462,8 +462,10 @@ describe('sends', () => {
 
   it('doesn\'t call a try that never started an attempt', async () => {
     const id = await t.engine.areaCall('outbox.queueSend', { summary, item }) as number;
-    await t.engine.areaCall('outbox.claim', { id });
-    await t.engine.areaCall('outbox.update', { id, status: 'waiting' });
+    for (let i = 0; i < 2; i += 1) {
+      await t.engine.areaCall('outbox.claim', { id });
+      await t.engine.areaCall('outbox.update', { id, status: 'waiting' });
+    }
     expect((await read()).entries[0].firstAttemptAt).toBeUndefined();
   });